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): September 1926, 2025

GOLUB CAPITAL BDC, INC.

(Exact name of Registrant as specified in its charter)

Delaware

814-00794

27-2326940

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

200 Park Avenue, 25th Floor, New York, NY 10166

(Address of Principal Executive Offices) (Zip Code)

Registrant’s telephone number, including area code: (212) 750-6060

(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 (see General Instruction A.2. below):

¨	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 communions 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 class		Trading Symbol (s)		Name of each exchange on which registered
Common Stock, par value $0.001 per share		GBDC		The Nasdaq 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 or Rule 12b-–2 of the Securities Exchange Act of 1934.

¨ 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 12.0103. ~~Entry~~Creation ~~into~~of a ~~Material~~Direct ~~Definitive~~Financial ~~Agreement.~~Obligation or an Obligation Under an Off-Balance Sheet Arrangement of a Registrant

On September 1926, 2025, Golub Capital BDC, Inc. (the “Company”) ~~entered~~issued ~~into~~ an ~~underwriting~~additional ~~agreement~~$250.0 million in aggregate principal amount of its 7.050% Notes due 2028 (the “~~Underwriting Agreement~~New Notes”) by and ~~among~~ the ~~Company,~~issuance GCand ~~Advisors~~sale ~~LLC~~of (the New Notes, the “~~Adviser~~Offering”). The New Notes were issued as additional notes under the base indenture, ~~Golub~~dated ~~Capital~~October ~~LLC~~2, 2020 (the “~~Administrator~~Base Indenture”), by and between the Company and ~~RBC~~U.S. ~~Capital~~Bank ~~Markets~~Trust Company, ~~LLC~~National Association (as successor in interest to U.S. Bank National Association), as trustee (the ~~underwriter~~“Trustee”), ~~set~~as ~~forth~~supplemented ~~therein~~by the Fourth Supplemental Indenture, indated ~~connection~~December ~~with~~5, 2023 (the ~~issuance~~“Fourth Supplemental Indenture” and ~~sale~~together ofwith anthe ~~additional~~Base Indenture, the “Indenture”), pursuant to which the Company initially issued $~~250~~450.0 ~~million~~ million in aggregate principal amount of the ~~Company’s~~ 7.050% Notes due 2028 (the “~~New~~Existing Notes” and ~~the~~together ~~issuance~~with ~~and sale of~~ the New Notes, the “~~Offering~~Notes”). ~~The closing of the Offering is expected to occur~~ on ~~September~~December 265, ~~2025, subject to customary closing conditions~~2023.

The ~~Underwriting~~New ~~Agreement~~Notes ~~includes~~are ~~customary~~treated ~~representations,~~as ~~warranties,~~a ~~and~~single ~~covenants~~series bywith the ~~Company,~~Existing Notes under the ~~Adviser,~~Indenture and have the ~~Administrator. It~~same ~~also~~terms ~~provides~~as ~~for~~the ~~customary~~Existing ~~indemnification~~Notes by(except the ~~each~~issue ofdate, the ~~Company,~~offering price and the ~~Adviser,~~initial interest payment date). The New Notes have the ~~Administrator,~~same CUSIP number and are fungible and rank equally with the ~~underwriter~~Existing ~~against~~Notes. ~~certain liabilities~~Upon ~~and~~issuance ~~customary~~of ~~contribution~~the ~~provisions~~New inNotes, ~~respect~~the outstanding aggregate principal amount of ~~those~~the ~~liabilities~~Company’s 7.050% Notes due 2028 is $700.0 million.

The ~~Offering~~Notes ~~was~~mature ~~made~~on ~~pursuant~~December to5, ~~the~~2028, ~~Company’s~~unless ~~effective~~previously ~~shelf~~redeemed ~~registration~~or ~~statement~~repurchased onin ~~Form~~accordance ~~N-2~~with ~~(File~~their Noterms. ~~333-286240)~~The ~~previously filed~~Notes ~~with~~bear ~~the~~interest ~~Securities~~at a ~~and~~rate ~~Exchange~~of ~~Commission~~7.050% ~~(the~~per ~~“SEC”),~~year aspayable ~~supplemented~~semi-annually byin aarrears ~~preliminary~~on ~~prospectus~~June ~~supplement~~5 ~~dated September~~and ~~19,~~December ~~2025,~~5 aof ~~final~~each ~~prospectus~~year, ~~supplement~~commencing ~~dated~~on ~~September~~December 195, 2025, ~~and~~for the New ~~pricing~~Notes. ~~term~~The ~~sheet~~Notes ~~filed~~are ~~with~~ the ~~SEC~~Company’s ongeneral ~~September 19,~~unsecured ~~2025.~~obligations ~~This~~that ~~Current~~rank ~~Report~~senior onin ~~Form~~right ~~8-K~~of ~~shall~~payment ~~not~~to ~~constitute~~all anof ~~offer~~the toCompany’s future ~~sell~~indebtedness or aother ~~solicitation~~obligations ofthat anare ~~offer~~expressly tosubordinated, ~~buy~~or ~~any securities~~junior, ~~nor shall~~in ~~there~~right beof ~~any~~payment ~~sale~~to ofthe ~~these~~Notes; ~~securities~~equal in ~~any~~right of ~~state~~payment orto ~~jurisdiction~~the inCompany’s ~~which~~existing ~~such~~and anfuture ~~offer,~~indebtedness ~~solicitation~~ or ~~sale~~other ~~would~~obligations bethat ~~unlawful~~are not so subordinated or junior; effectively ~~prior~~junior to ~~registration~~any of the Company’s secured indebtedness or ~~qualification~~other ~~under~~obligations (including unsecured indebtedness that the ~~securities~~Company ~~laws~~later secures) to the extent of ~~any~~the value of the assets securing such ~~state~~indebtedness; orand structurally junior to all existing and future indebtedness and other ~~jurisdiction~~obligations (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

~~The~~Prior ~~foregoing~~to ~~description~~November 5, 2028 (one month prior to the maturity date of the ~~Underwriting~~Notes) ~~Agreement~~(the ~~does~~“Par ~~not~~Call ~~purport~~Date”), the Company may redeem the Notes at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of: (1) 100% of the principal amount of the Notes to be ~~complete~~redeemed, plus, in either case, accrued and isunpaid ~~qualified~~interest thereon to the redemption date, or (2) (a) the sum of the present values of the remaining scheduled payments of principal and interest thereon discounted to the redemption date (assuming the Notes matured on the Par Call Date) on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate (as defined in ~~its~~the ~~entirety~~Fourth bySupplemental ~~reference~~Indenture) plus 45 basis points less (b) interest accrued to the date of redemption. On or after the Par Call Date, the Company may redeem the Notes, in whole or in part, at any time and from time ~~full~~to ~~text~~time, at a redemption price equal to 100% of the ~~Underwriting~~principal ~~Agreement~~amount ~~filed~~of the Notes being redeemed plus accrued and unpaid interest thereon to the redemption date. No sinking fund is provided for the Notes. In addition, if a Change of Control Repurchase Event (as andefined ~~exhibit~~in the ~~hereto~~Fourth Supplemental Indenture) occurs in respect of the Company prior to maturity, holders of the Notes may require the Company to repurchase for cash some or all of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and ~~incorporated~~unpaid byinterest ~~reference~~to, ~~herein~~but not including, the repurchase date.

The Indenture contains certain covenants, including a covenant requiring the Company to comply with Section 18(a)(1)(A) as modified by Section 61(a)(1) and (2) of the Investment Company Act of 1940, as amended, or any successor provisions, but giving effect to any exemptive relief granted to the Company by the Securities and Exchange Commission (the “SEC”), and to provide financial information to the holders of the Notes and the Trustee if the Company should no longer be subject to the reporting requirements under the Securities Exchange Act of 1934, as amended. These covenants are subject to important limitations and exceptions that are set forth in the Indenture.

The Company intends to use the net proceeds of the Offering to repay a portion of the outstanding indebtedness under the Company’s senior secured revolving credit facility with JPMorgan Chase Bank, N.A. (the “JPM Credit Facility”). However, the Company may re-borrow under the JPM Credit Facility or borrow under the Company’s line of credit with GC Advisors LLC for general corporate purposes, which may include investing in portfolio companies in accordance with the Company’s investment strategy.

The Offering was made pursuant to the Company’s effective shelf registration statement on Form N-2 (File No. 333-286240) previously filed with the SEC, as supplemented by a preliminary prospectus supplement dated September 19, 2025, the pricing term sheet filed with the SEC on September 19, 2025, and a final prospectus supplement dated September 19, 2025. This Current Report on Form 8-K shall not constitute an offer to sell or a solicitation of an offer to buy any securities, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction. The transaction closed on September 26, 2025.

The description above is only a summary of the material provisions of the Base Indenture, the Fourth Supplemental Indenture, and the Notes and is qualified in its entirety by reference to copies of the Base Indenture, the Fourth Supplemental Indenture, and the form of global note representing the Notes, respectively, which are incorporated by reference herein.

Item 9.01.

Financial Statements and Exhibits.

(d) Exhibits

EXHIBIT NUMBER		DESCRIPTION
1.1		Underwriting Agreement, dated September 19, 2025, by and among Golub Capital BDC, Inc., GC Advisors LLC, Golub Capital LLC, and RBC Capital Markets, LLC, as the underwriter set forth therein.
4.1		Indenture, dated as of October 2, 2020, by and between Golub Capital BDC, Inc. and U.S. Bank National Association, as trustee (incorporated by reference to Exhibit 4.1 to Current Report on Form 8-K filed on October 2, 2020)
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).
4.2		Fourth Supplemental Indenture, dated as of December 5, 2023, relating to the 7.050% Notes due 2028, by and between Golub Capital BDC, Inc. and U.S. Bank Trust Company, National Association (as successor in interest to U.S. Bank National Association), as trustee (incorporated by reference to Exhibit 4.2 to the Current Report on Form 8-K filed on December 5, 2023)
4.3		Form of Global Note with respect to 7.050% Notes due 2028 (included in Exhibit 4.2 to the Current Report on Form 8-K filed on December 5, 2023 and incorporated by reference herein)
5.1		Opinion of Eversheds Sutherland (US) LLP
23.1		Consent of Eversheds Sutherland (US) LLP (contained in the opinion filed as Exhibit 5.1 hereto)
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURE

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

	Golub Capital BDC, Inc.	~~Golub Capital BDC, Inc.~~
Date: September 25, 2025		By:	/s/ Christopher C. Ericson
Date: September 26, 2025	By:	/s/ Christopher C. Ericson
		Christopher C. Ericson	~~Christopher C. Ericson~~
		Chief Financial Officer and Treasurer	~~Chief Financial Officer and Treasurer~~

Filing Compare · GOLUB CAPITAL BDC, Inc.