BAND

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 19, 2026

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On February 19, 2026, Bandwidth Inc. issued a press release reporting its financial results for the fourth quarter and full year ended December 31, 2025. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated February 19, 2026 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: February 19, 2026By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20251030FALSE000151441600015144162025-10-302025-10-30

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) October 30, 2025

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On October 30, 2025, Bandwidth Inc. issued a press release reporting its financial results for the third quarter ended September 30, 2025. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated October 30, 2025 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: October 30, 2025By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20250729FALSE000151441600015144162025-07-292025-07-29

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) July 29, 2025

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On July 29, 2025, Bandwidth Inc. issued a press release reporting its financial results for the second quarter ended June 30, 2025. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated July 29, 2025 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: July 29, 2025By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20250507FALSE000151441600015144162025-05-072025-05-07

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 7, 2025

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On May 7, 2025, Bandwidth Inc. issued a press release reporting its financial results for the first quarter ended March 31, 2025. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated May 7, 2025 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: May 7, 2025By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20250220FALSE000151441600015144162025-02-202025-02-20

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 20, 2025

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On February 20, 2025, Bandwidth Inc. (the “Company”) issued a press release reporting its financial results for the fourth quarter and full year ended December 31, 2024. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 8.01 Other Events. On February 19, 2025, the Company entered into separate, privately negotiated repurchase agreements with a limited number of holders of its 0.250% Convertible Senior Notes due 2026 (the “Notes”) to repurchase (the “Repurchases”) approximately $27.4 million aggregate principal amount of the Notes for approximately $26.1 million, excluding customary transaction fees. The repurchase price payable by Bandwidth will be paid in cash. The Company has previously entered into capped call transactions with certain financial institutions in connection with the Notes. All of these transactions are expected to remain in effect notwithstanding the Repurchases. The Repurchases are expected to close on February 24, 2025, subject to the satisfaction of customary closing conditions. Following the Repurchases, approximately $7.6 million principal amount of the Notes will remain outstanding. The information furnished with this Item 8.01 shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated February 20, 2025 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: February 20, 2025By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20241028FALSE000151441600015144162024-10-282024-10-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) October 28, 2024

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement. On October 28, 2024, Bandwidth Inc. (the “Company”) entered into a second amendment (the “Credit Agreement Amendment”) to the credit agreement (as amended, the “Credit Agreement”) among the Company, as borrower, certain subsidiaries of the Company, as guarantors, the lenders from time to time party thereto, and Bank of America, N.A., as administrative agent, swingline lender and letters of credit issuer, with BofA Securities, Inc. and Wells Fargo Securities, LLC as Joint Lead Arrangers and Joint Bookrunners. Effective as of October 28, 2024, the Credit Agreement was amended to: •increase the aggregate revolving credit commitments from $100.0 million to $150.0 million; •with respect to applicable interest rates, modify the applicable margin for loans based on SOFR to between 2.00% and 2.50%, and modify the applicable margin for loans based on the base rate to between 1.00% and 1.50%, in each case depending upon the Company’s consolidated total leverage ratio for the most recent fiscal quarter for which financial statements have been delivered under the Credit Agreement; •modify the quarterly commitment fee to between 0.20% and 0.25% on the unused portion of the borrowing commitment, depending upon the Company’s consolidated total leverage ratio for the most recent fiscal quarter for which financial statements have been delivered under the Credit Agreement; •replace the existing financial covenants with the following new financial covenants: (a) (1) for each fiscal quarter ending on or prior to June 30, 2025, a consolidated senior secured leverage ratio not to exceed 2.75 to 1.00, and (2) for each fiscal quarter thereafter, a consolidated senior secured leverage ratio not to exceed 2.50 to 1.00; and (b) a consolidated fixed charge coverage ratio not less than 2.00 to 1.00, in each case tested as of the end of any fiscal quarter; •modify exceptions to certain customary negative covenants to require a pro forma consolidated senior secured leverage ratio at least 0.50 to 1.00 inside the maximum then-applicable consolidated senior secured leverage ratio, and modify the exception to the restriction on additional convertible indebtedness to require a pro forma consolidated total leverage ratio over the most recent four fiscal quarters not to exceed 4.50 to 1.00; and •modify the maturity date to the earlier of (a) May 1, 2029 or (b) the date that is 91 days prior to the scheduled maturity date or mandatory conversion date of any of the Company’s outstanding convertible senior notes due 2028. Except as described above, the terms of any loans under the Credit Agreement are unmodified and remain in full force and effect.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 1, 2024

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On August 1, 2024, Bandwidth Inc. issued a press release reporting its financial results for the second quarter ended June 30, 2024. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated August 1, 2024 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: August 1, 2024By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20240507FALSE000151441600015144162024-05-072024-05-07

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 7, 2024

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement. On May 1, 2024, Bandwidth Inc. (the “Company”) entered into an amendment (the “Credit Agreement Amendment”) to the credit agreement (as amended, the “Credit Agreement”) among the Company, as borrower, certain subsidiaries of the Company, as guarantors, the lenders from time to time party thereto, and Bank of America, N.A., as administrative agent, swingline lender and letters of credit issuer, with BofA Securities, Inc. and Wells Fargo Securities, LLC as Joint Lead Arrangers and Joint Bookrunners. Effective as of May 1, 2024, the Credit Agreement was amended to: •increase the aggregate revolving credit commitments from $50.0 million to $100.0 million; •increase the swingline sublimit from $5.0 million to $10.0 million; •increase from $75.0 million to $82.5 million the minimum liquidity (which includes the amount of undrawn borrowing commitments available under the Credit Agreement) the Company is required to maintain, tested (a) as of the end of any fiscal quarter and (b) as of each incurrence of certain actions in reliance on negative covenant baskets that are subject to a minimum liquidity condition; and •extend the maturity date to the earlier of May 1, 2029 (previously August 1, 2028) or the date that is 91 days prior to the scheduled maturity date or mandatory conversion date of any of the Company’s outstanding convertible notes. Except as described above, the terms of any loans under the Credit Agreement are unmodified and remain in full force and effect. This summary of the Credit Agreement Amendment is qualified in its entirety by reference to the full text of the First Amendment to Credit Agreement, dated as of May 1, 2024, which will be filed as an exhibit to the Company’s Quarterly Report on Form 10-Q for the quarter ending March 31, 2024.

Item 2.02 Results of Operations and Financial Condition. On May 7, 2024, the Company issued a press release reporting its financial results for the first quarter ended March 31, 2024. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement. The information set forth above under Item 1.01 is hereby incorporated by refe

band-20240228FALSE000151441600015144162024-02-282024-02-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 28, 2024

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On February 28, 2024, Bandwidth Inc. (the “Company”) issued a press release reporting its financial results for the fourth quarter ended December 31, 2023. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On February 26, 2024, the Company entered into a Second Amendment to Employment Agreement (the “Amendment”) with David Morken, the Company’s Chief Executive Officer, to amend the terms of his employment agreement, dated January 1, 2015 (as amended, the “Morken Agreement”), with the Company. Under the Amendment: a.In the event of a termination of Mr. Morken’s employment by the Company without “cause”, or his resignation of employment for “good reason” (as such terms are defined in the Morken Agreement) (a “Qualifying Termination”), and subject to his timely execution and non-revocation of a general release of claims, Mr. Morken will be also be entitled to receive a lump sum amount equal to eighteen (18) months of premiums for the term life insurance coverage the Company has in effect for him as of the date of his termination. b.If a Qualifying Termination occurs within twelve (12) months following a “change in control” or Mr. Morken terminates his employment for any reason within twelve (12) months following an “unapproved change in control,” (as described in the Morken Agreement), then in lieu of any other severance payments and benefits, Mr. Morken will be entitled to three hundred percent (300%) of his prior year’s base salary and bonus compensation (determined based on the achievement of target performance levels for the year of termination), plus a healthcare stipend, grossed up for taxes, in an amount sufficient to facilitate his purchase of healthcare coverage for a period of thirty-six (36) months, plus a lump sum amount equal to thirty (36) months of premiums for the term life insurance coverage the Company has in effect for him as of the date of his termination. c.The provisions related to a bonus upon an initial public offering and a bonus upon certain liquidity events were removed. The fo

band-20231102FALSE0001514416December 3100015144162023-11-022023-11-02

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 2, 2023

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On November 2, 2023, Bandwidth Inc. (the “Company”) issued a press release reporting its financial results for the third quarter ended September 30, 2023. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. On November 2, 2023, the Company’s Board of Directors (the “Board”) approved and adopted an amendment and restatement of the Company’s bylaws (the “Third Amended and Restated Bylaws”), which became effective the same day. Among other things, the amendments effected by the Third Amended and Restated Bylaws: •address the universal proxy rules adopted by the U.S. Securities and Exchange Commission, by clarifying that no person may solicit proxies in support of a director nominee other than the Board’s nominees unless such person has complied with Rule 14a-19 under the Securities Exchange Act of 1934, as amended, including applicable notice and solicitation requirements; and •enhance procedural mechanics and disclosure requirements in connection with stockholder nominations of directors and submissions of proposals regarding other business at stockholder meetings, including requiring additional background information and disclosures regarding proposing stockholders, proposed nominees and business, and other persons related to a stockholder’s solicitation of proxies, such as additional information about the ownership of securities and material litigation, relationships and interests in material agreements with or involving the Company. The Third Amended and Restated Bylaws also include certain technical, modernizing and clarifying changes. The foregoing summary does not purport to be complete and is qualified in its entirety by reference to the full text of the Third Amended and Restated Bylaws, a copy of which is filed as Exhibit 3.1 to this Current Report on Form 8-K and incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 3.1 Third Amended and Restated Bylaws of Bandwidth Inc., effective as of November 2, 2023 99.1 Bandwidth Inc. press release, dated November 2, 2023 104Cover Page Interactive File (

band-20230801FALSE000151441600015144162023-08-012023-08-01

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 1, 2023

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

2230 Bandmate Way Raleigh, NC 27607 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement. On August 1, 2023, Bandwidth Inc. (the “Company”) entered into a credit agreement (the “Credit Agreement”) among the Company, as borrower, the lenders from time to time party thereto, and Bank of America, N.A., as administrative agent, swingline lender and letters of credit issuer. The Credit Agreement provides for a $50.0 million revolving credit facility (the “Credit Facility”), including a $15.0 million sublimit for the issuance of letters of credit and a swingline subfacility of up to $5.0 million. The Credit Facility has an accordion feature that allows for an increase in the total borrowing size up to $25.0 million, subject to certain conditions. The Credit Facility matures on the earlier of (a) August 1, 2028 or (b) the date that is 91 days prior to the scheduled maturity date or mandatory conversion date of any of the Company’s outstanding convertible notes. Interest on borrowings under the Credit Facility accrues at an annual rate tied to a base rate or the Secured Overnight Financing Rate (“SOFR”), at the Company’s election. Loans based on SOFR bear interest at a rate equal to term SOFR for the applicable interest period plus 10 basis points plus an applicable margin between 2.25% and 2.75% , and loans based on the base rate bear interest at a rate equal to the base rate plus an applicable margin between 1.25% and 1.75%, in each case of the foregoing, depending upon the Company’s consolidated EBITDA for the most recent period of four consecutive fiscal quarters for which financial statements have been delivered under the Credit Agreement. The Company is required to pay a quarterly commitment fee equal to between 0.05% and 0.0625% on the unused portion of the borrowing commitment, depending upon the Company’s consolidated EBITDA for the most recent period of four consecutive fiscal quarters for which financial statements have been delivered under the Credit Agreement. The obligations under the Credit Agreement are secured by a lien on substantially all of the Company’s tangible and intangible property and by a pledge of all of the equity interests of the Company’s direct domestic subsidiaries and 65% of the voting capital stock and 100% of the non-voting capital stock of any first-tier foreign subsidiaries, subject to limited exceptions. In addition, the Company’s direct domestic subsidiaries guarantee the obligations under the Credit Agreement and grant a lien and pledge, as applicable, on substantially all of their tangible and intangible property to secure the obligations under the Credit Agreement. The Credit Agreement contains customary covenants (subject, in each case, to certain exceptions), inclu

band-20230502FALSE000151441600015144162023-05-022023-05-02

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 2, 2023

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On May 2, 2023, Bandwidth Inc. (“Bandwidth”) issued a press release reporting its financial results for the first quarter ended March 31, 2023. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated May 2, 2023 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: May 2, 2023By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20230221FALSE000151441600015144162023-02-212023-02-21

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 21, 2023

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On February 23, 2023, Bandwidth Inc. (“Bandwidth”) issued a press release reporting its financial results for the fourth quarter ended December 31, 2022. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended (the “Securities Act”), except as expressly set forth by specific reference in such a filing.

Item 5.02 Departure of Directors or Principal Officers; Election of Directors; Appointment of Principal Officers. On February 21, 2023, the board of directors of Bandwidth appointed Devin M. Krupka, Bandwidth’s Controller, as Bandwidth’s principal accounting officer. Daryl E. Raiford, who had previously been designated as Bandwidth’s principal accounting officer, will continue in his role as Bandwidth’s Chief Financial Officer and principal financial officer. Mr. Krupka, age 36, joined Bandwidth in August 2016 and served in various internal audit and accounting roles until March 2022, when he was named as Senior Vice President, Corporate Controller. From 2008 to 2012, Mr. Krupka was an Associate and then Senior Associate with PricewaterhouseCoopers in its external audit practice. Mr. Krupka obtained a Bachelor of Arts from Cedarville University in dual majors of Accounting and Finance, and is a Certified Public Accountant. There are no arrangements or understandings between Mr. Krupka and any other person pursuant to which Mr. Krupka was named as principal accounting officer. There are no transactions between Mr. Krupka and Bandwidth that would be reportable under Item 404(a) of Regulation S-K.

Item 7.01 Regulation FD Disclosure. As previously announced through a press release, dated February 2, 2023, issued by Bandwidth, on February 23, 2023, representatives of Bandwidth’s management team will hold a virtual investor day from 8:30 am to 10:00 am ET. The investor presentation will be posted at 8:30 am on February 23, 2023 on Bandwidth’s investor relations website at investors.bandwidth.com.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated February 23, 2023 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 19

band-20221101FALSE000151441600015144162022-11-012022-11-01

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 1, 2022

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On November 1, 2022, Bandwidth Inc. (“Bandwidth”) issued a press release reporting its financial results for the third quarter ended September 30, 2022. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On October 31, 2022, Marina C. Carreker informed Bandwidth that she has decided to resign her position as President of Bandwidth, effective December 31, 2022. Ms. Carreker’s resignation is not due to any disagreement with Bandwidth, its board of directors or management, or any matter relating to Bandwidth’s operations, policies or practices.

Item 8.01 Other Events. Bandwidth announced that it has entered into separate, privately negotiated repurchase agreements with a limited number of holders of its 0.250% Convertible Senior Notes due 2026 (the “Notes”) to repurchase (the “Repurchases”) approximately $160 million aggregate principal amount of the Notes at approximately a 29 percent discount to par value. The repurchase price payable by Bandwidth will be paid in cash and will be based in part on the daily volume-weighted average price per share of Bandwidth’s Class A common stock over a 15 consecutive trading day measurement period beginning on, and including, November 2, 2022. Bandwidth has previously entered into capped call transactions with certain financial institutions in connection with the Notes. All of these transactions are expected to remain in effect notwithstanding the Repurchases. The Repurchases are expected to close on November 28, 2022, subject to the satisfaction of customary closing conditions. Following such closings, approximately $240 million principal amount of the Notes will remain outstanding. The information furnished with this Item 8.01 shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

band-20220803FALSE000151441600015144162022-08-032022-08-03

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 3, 2022

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On August 3, 2022, Bandwidth Inc. issued a press release reporting its financial results for the second quarter ended June 30, 2022. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated August 3, 2022 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: August 3, 2022By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20220504FALSE000151441600015144162022-05-042022-05-04

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 4, 2022

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On May 4, 2022, Bandwidth Inc. issued a press release reporting its financial results for the first quarter ended March 31, 2022. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated May 4, 2022 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: May 4, 2022By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20220223FALSE000151441600015144162022-02-232022-02-23

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 23, 2022

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On February 23, 2022, Bandwidth Inc. issued a press release reporting its financial results for the fourth quarter ended December 31, 2021. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated February 23, 2022 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: February 23, 2022By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20211108FALSE000151441600015144162021-11-082021-11-08

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 8, 2021

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On November 8, 2021, Bandwidth Inc. issued a press release reporting its financial results for the third quarter ended September 30, 2021. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated November 8, 2021 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: November 8, 2021By:/s/ Daryl E. Raiford Name:Daryl E. Raiford Title:Chief Financial Officer

band-20210805FALSE000151441600015144162021-08-052021-08-05

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 5, 2021

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On August 5, 2021, Bandwidth Inc. (“the Company” or “Bandwidth”) issued a press release reporting its financial results for the second quarter ended June 30, 2021. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated August 5, 2021 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: August 5, 2021By:/s/ Jeffrey A. Hoffman Name:Jeffrey A. Hoffman Title:Chief Financial Officer

band-20210503FALSE000151441600015144162021-05-032021-05-03

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 3, 2021

BANDWIDTH INC.

(Exact name of registrant as specified in its charter)

Delaware001-3828556-2242657 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.)

900 Main Campus Drive Raleigh, NC 27606 (Address of principal executive offices) (Zip Code) (800) 808-5150 Registrant’s telephone number, including area code Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading Symbol(s)Name of each exchange on which registered Class A Common Stock, par value $0.001 per shareBANDNASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company   ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On May 5, 2021, Bandwidth Inc. (“the Company” or “Bandwidth”) issued a press release reporting its financial results for the first quarter ended March 31, 2021. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The information furnished with this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On May 3, 2021, Jeffrey A. Hoffman informed the Company that he has decided to step down as Chief Financial Officer of Bandwidth. Mr. Hoffman’s last day at Bandwidth will be August 31, 2021, and he has offered to work with the Company in an effort to ensure an orderly transition. Mr. Hoffman’s resignation is not due to any disagreement with Bandwidth, its board of directors or management, or any matter relating to the Company’s operations, policies or practices.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.Description 99.1 Bandwidth Inc. press release, dated May 5, 2021 99.2 Letter from Jeff Hoffman to David Morken of Bandwidth Inc. dated May 3, 2021 104Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BANDWIDTH INC.

Date: May 5, 2021By:/s/ Jeffrey A. Hoffman Name:Jeffrey A. Hoffman Title:Chief Financial Officer