false

10-K

Entity Address, Address Line One

200 Park Avenue

Entity Address, City or Town

New York

Entity Address, Postal Zip Code

10166

Local Phone Number

750-6060

Entity Emerging Growth Company

false

Shareholder Transaction Expenses [Table Text Block]


Stockholder transaction expenses:
Sales load (as a percentage of offering price)	0	%	(1)
Offering expenses (as a percentage of offering price)	0	%	(2)
Dividend reinvestment plan expenses	None		(3)
Total stockholder transaction expenses (as a percentage of offering price)	0	%


Annual expenses (as a percentage of net assets attributable to common stock):(4)
Management fees	2.19	%	(5)
Incentive fees payable under the Investment Advisory Agreement	1.82	%	(6)
Interest payments on borrowed funds	7.22	%	(7)
Other expenses	0.54	%	(8)

Total annual expenses	11.77	%	(9)

(1)In the event that the securities to which any applicable prospectus relates are sold to or through underwriters or agents, a corresponding prospectus supplement will disclose the applicable sales load.

(2)In the event that we conduct an offering of our securities, the related prospectus supplement will disclose the estimated amount of total offering expenses (which could include offering expenses borne by third parties on our behalf), the offering price and the offering expenses borne by us as a percentage of the offering price.

(3)The expenses associated with the dividend reinvestment plan are included in “Other expenses.” See “Dividend Reinvestment Plan.”.

(4)Our total net assets as of September 30, 2025 was $3,983 million. The daily average net assets for the year ended September 30, 2025, employed as the denominator for expense ratio computation was $4,025 million.

(5)Our management fee is calculated at an annual rate equal to 1.0% and is based on the average adjusted gross assets (including assets purchased with borrowed funds and securitization-related assets, leverage, unrealized depreciation or appreciation on derivative instruments and cash collateral on deposit with custodian but adjusted to exclude cash and cash equivalents so that investors do not pay the base management fee on such assets) at the end of the two most recently completed calendar quarters and is payable quarterly in arrears. See “Item 1. Business — Management Agreements” and “Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations - Recent Developments”. The management fee referenced in the table above is annualized and based on actual amounts incurred during the year ended September 30, 2025 by GC Advisors in its capacity as investment adviser to us and collateral manager to the 2024 Issuer, the 2018 Issuer, the GCIC 2018 Issuer, the GBDC 3 2021 Issuer, the GBDC 3 2022 Issuer and the GBDC 3 2022-2 Issuer, collectively the Securitization Issuers. The adjusted estimate of our annualized base management fees based on actual expenses for the year ended September 30, 2025 assumes average net assets of $4,025 million and average leverage of $4,893 million, which reflects our average net assets and average net leverage as of September 30, 2025.

GC Advisors, as collateral manager for our indirect, wholly owned, consolidated subsidiary, Golub Capital BDC CLO 8 LLC, or the 2024 Issuer, under a collateral management agreement, or the 2024 Issuer Collateral Management Agreement, is entitled to receive an annual fee in an amount equal to 0.35% of the principal balance of the portfolio loans held by the 2024 Issuer at the beginning of the collection period relating to each payment date, which is payable in arrears on each payment date. Under the 2024 Issuer Collateral Management Agreement, the term “collection period” refers to the period commencing on the third business day prior to the preceding payment date and ending on (but excluding) the third business day prior to such payment date.

Prior to the redemption of the notes, or 2018 Notes, offered in our $602.4 million term debt securitization initially completed on November 16, 2018, or the 2018 Debt Securitization, and termination of the documents governing the 2018 Debt Securitization on November 18, 2024, GC Advisors served as collateral manager for Golub Capital BDC CLO III LLC, a Delaware limited liability company, or LLC, and, prior to its dissolution, our indirect subsidiary, or the 2018 Issuer, under a collateral management agreement, or the 2018 Collateral Management Agreement, and was entitled to receive an annual fee in an amount equal to 0.25% of the principal balance of the portfolio loans held by the 2018 Issuer at the beginning of the collection period relating to each payment date, which was payable in arrears on each payment date. Under the 2018 Collateral Management Agreement, the term “collection period” referred to the period commencing on the third business day prior to the preceding payment date and ending on (but excluding) the third business day prior to such payment date.

Prior to the redemption of the notes, or the GCIC 2018 Notes, offered in the $908.2 million term debt securitization, or the GCIC 2018 Debt Securitization, that we assumed effective September 16, 2019 as a result of our acquisition of Golub Capital Investment Corporation, a Maryland corporation, or the GCIC Merger, and the termination of the documents governing the GCIC 2018 Debt Securitization, GC Advisors served as collateral manager for Golub Capital Investment Corporation CLO II LLC, or the GCIC 2018 Issuer, under a collateral management agreement, or the GCIC 2018 Collateral Management Agreement, and was entitled to receive an annual fee in an amount equal to 0.35% of the principal balance of the portfolio loans held by the GCIC 2018 Issuer at the beginning of the collection period relating to each payment date, which was payable in arrears on each payment date. Under the 2018 GCIC Collateral Management Agreement, the term “collection period” generally referred to a quarterly period commencing on the day after the end of the prior collection period to the tenth business day prior to the payment date.

Prior to the redemption of the notes, or the GBDC 3 2021 Notes, offered in the $398.9 million term debt securitization, or the GBDC 3 2021 Debt Securitization, that we assumed effective June 3, 2024 as a result of our acquisition of Golub Capital BDC 3, Inc., a Maryland corporation, or the GBDC 3 Merger, and the termination of the documents governing the GBDC 3 2021 Debt Securitization, GC Advisors served as collateral manager for Golub Capital BDC 3 CLO 1 LLC, or the GBDC 3 2021 Issuer, an LLC and, prior to its dissolution, our indirect, wholly owned, consolidated subsidiary, under a collateral management agreement, or the GBDC 3 2021 Collateral Management Agreement, and was entitled to receive an annual fee in an amount equal to 0.35% of the principal balance of the portfolio loans held by the GBDC 3 2021 Issuer at the beginning of the collection period relating to each payment date, which was payable in arrears on each payment date. Under the GBDC 3 2021 Collateral Management Agreement, the term “collection period” referred to the period commencing on the tenth business day prior to the preceding payment date and ending on (but excluding) the tenth business day prior to such payment date.

Prior to the redemption of the GBDC 3 2022 Notes and the termination of the documents governing the GBDC 3 2022 Debt Securitization, GC Advisors served as collateral manager for the GBDC 3 2022 Issuer, under the 2022 Collateral Management Agreement and was entitled to receive an annual fee in an amount equal to 0.35% of the principal balance of the portfolio loans held by the GBDC 3 2022 Issuer at the beginning of the collection period relating to each payment date, which was payable in arrears on each payment date. Under the GBDC 3 2022 Collateral Management Agreement, the term “collection period” relating to any payment date, referred to the period commencing on the tenth business day prior to the preceding payment date and ending on (but excluding) the tenth business day prior to such payment date.

GC Advisors served as collateral manager for our indirect, wholly owned, consolidated subsidiary, Golub Capital BDC 3 ABS 2022-1 LLC, or the GBDC 3 2022 Issuer, prior to the redemption of the GBDC 3 2022 Notes, under a collateral management agreement, or the GBDC 3 2022-2 Collateral Management Agreement, and was entitled to receive an annual fee in an amount equal to 0.35% of the principal balance of the portfolio loans held by the GBDC 3 2022 Issuer at the beginning of the collection period relating to each payment date, which is payable in arrears on each payment date. Under the GBDC 3 2022 Collateral Management Agreement, the term “collection period” relating to any payment date, referred to the period commencing on the tenth business day prior to the preceding payment date and ending on (but excluding) the tenth business day prior to such payment date..

Collateral management fees are paid directly by the 2018 Issuer, GCIC 2018 Issuer, GBDC 3 2021 Issuer, GBDC 3 2022 Issuer, GBDC 2 2022-2 Issuer and the 2024 Issuer and are offset against the management fees payable under the Investment Advisory Agreement. Term debt securitizations are also known as CLOs, and are a form of secured financing incurred by us, which are consolidated by us and subject to our overall asset coverage requirement.

For purposes of this table, the SEC requires that the “Management fees” percentage be calculated as a percentage of net assets attributable to common stock, rather than total assets, including assets that have been funded with borrowed monies, because common stockholders bear all of this cost. If the base management fee portion of the “Management fees” percentage were calculated instead as a percentage of our total assets, our base management fee portion of the “Management fees” percentage would be approximately 0.98% of total assets.

(6)The incentive fee referenced in the table above is based on actual amounts of the income component of the incentive fee incurred during the year ended September 30, 2025. The incentive fee referenced in the table above is calculated under the Investment Advisory Agreement based on actual amounts of the income component of the incentive fee for GBDC. As of September 30, 2025, no amount was payable for the capital gains component under the Investment Advisory Agreement. We have structured the calculation of the incentive fee to include a fee limitation such that no incentive fee will be paid to GC Advisors for any quarter if, after such payment, the cumulative incentive fees paid to GC Advisors since the effective date of our election to become a business development company would be greater than 15.0% of our cumulative pre-incentive fee net income per share. For a more detailed discussion of the calculation of the incentive fee, see “Item 1. Business - Management Agreement - Income and Capital Gains Incentive Fee Calculation” as well as any amendments reflected in subsequent filings with the SEC.

(7)Interest payments on borrowed funds is based on our cost of funds on our outstanding indebtedness for the year ended September 30, 2025, which consisted of $1,137.6 million of indebtedness outstanding under revolving credit facilities, $1,364.0 million in notes issued through the Debt Securitizations, $600.0 million of 2026 Notes, $350.0 million of 2027 Notes, $700.0 million of 2028 Notes and $750.0 million of 2029 Notes. For the year ended September 30, 2025, the annualized cost of funds for our total debt outstanding, which includes all interest, accretion of discounts, and amortization of debt issuance costs on the Debt Securitizations, was 5.8%. Debt issuance costs represent fees and other direct incremental costs incurred in connection with our Debt Securitizations. These fees include structuring and placement fees paid by the 2018 Issuer to Morgan Stanley & Co. LLC for its services in connection with the structuring of the 2018 Debt Securitization and by the 2024 Issuer to Deutsche Bank Securities Inc. for its services in connection with the structuring of the 2024 Debt Securitization. Before we acquired the GCIC 2018 Issuer as part of the GCIC Merger, the GCIC 2018 Issuer paid Wells Fargo Securities, LLC structuring and placement fees for its services in connection with the initial structuring of the GCIC 2018 Debt Securitization. Before we acquired the GBDC 3 2021 Issuer as a part of the GBDC 3 Merger, the GBDC 3 2021 Issuer paid Deutsche Bank AG, New York Branch, structuring and placement fees for its services in connection with the structuring of each of the GBDC 3 2021 Debt Securitization and the GBDC 3 2022 Debt Securitization. Before we acquired the GBDC 3 2022-2 Issuer as a part of the GBDC 3 Merger, the GBDC 3 2022-2 Issuer paid GreensLedge Capital Markets LLC and KeyBanc Capital Markets Inc. structuring and placement fees for its services in connection with the structuring of the GBDC 3 2022-2 Debt Securitization.

(8)Includes our overhead expenses, including payments under the Administration Agreement based on our allocable portion of overhead and other expenses incurred by the Administrator, and any acquired fund fees and expenses that are not required to be disclosed separately. See “Item 1. Management Agreements - Administration Agreements”, as well as any amendments reflected in subsequent filings with the SEC. “Other expenses” also includes the ongoing administrative expenses to the trustee, collateral manager, independent accountants, legal counsel, rating agencies and independent managers in connection with developing and maintaining reports and providing required services in connection with the administration of each of the Debt Securitizations. Additionally, “Other expenses” includes the actual amount incurred for U.S. federal excise tax. “Other expenses” are based on actual amounts incurred for the year ended September 30, 2025. The administrative expenses of each of the Securitization Issuers are paid on each payment date in two parts: (1) a component that is paid in a priority to other amounts distributed by the applicable Securitization Issuer, subject to a cap equal to the sum of 0.04% per annum of the adjusted principal balance of the portfolio loans and other assets held by the applicable Securitization Issuer on the last day of the collection period relating to such payment date, plus $150,000 per annum, and (2) a component that is paid in a subordinated position relative to other amounts distributed by the applicable Securitization Issuer equal to any amounts that exceed the aforementioned administrative expense cap.

(9)All of our expenses, including all expenses of each of the Debt Securitizations, are disclosed in the appropriate line items under “Annual Expenses (as a percentage of net assets attributable to common stock).” “Total annual expenses” as a percentage of consolidated net assets attributable to common stock are higher than the total annual expenses percentage would be for a company that is not leveraged. We borrow money to leverage our net assets and increase our total assets. The SEC requires that the “Total annual expenses” percentage be calculated as a percentage of net assets (defined as total assets less indebtedness and after taking into account any incentive fees payable during the period), rather than the total assets, including assets that have been funded with borrowed monies. The reason for presenting expenses as a percentage of net assets attributable to common stockholders is that our common stockholders bear all of our fees and expenses.

Dividend Reinvestment and Cash Purchase Fees

$ 0

Other Transaction Expenses [Percent]

0.00%

Management Fees [Percent]

2.19%

Incentive Fees [Percent]

1.82%

Other Annual Expenses [Percent]

0.54%

Expense Example [Table Text Block]

The following example demonstrates the projected dollar amount of total cumulative expenses that would be incurred over various periods with respect to a hypothetical investment in our common stock. This example and the expenses in the table above should not be considered a representation of our future expenses, and actual expenses (including the cost of debt, if any, and other expenses) could be greater or less than those shown.


You would pay the following expenses on a $1,000 investment	1 year	3 years	5 years	10 years
Assuming a 5% annual return (assumes no return from net realized capital gains or net unrealized capital appreciation)	$114	$295	$459	$803
Assuming a 5% annual return (assumes return entirely from realized capital gains and thus subject to the capital gain incentive fee)	$121	$314	$486	$836

Expense Example, Years 1 to 3

295

Expense Example, Years 1 to 10

$ 803

Management Fee not based on Net Assets, Note [Text Block]

ur management fee is calculated at an annual rate equal to 1.0% and is based on the average adjusted gross assets (including assets purchased with borrowed funds and securitization-related assets, leverage, unrealized depreciation or appreciation on derivative instruments and cash collateral on deposit with custodian but adjusted to exclude cash and cash equivalents so that investors do not pay the base management fee on such assets) at the end of the two most recently completed calendar quarters and is payable quarterly in arrears. See “Item 1. Business — Management Agreements” and “Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations - Recent Developments”. The management fee referenced in the table above is annualized and based on actual amounts incurred during the year ended September 30, 2025 by GC Advisors in its capacity as investment adviser to us and collateral manager to the 2024 Issuer, the 2018 Issuer, the GCIC 2018 Issuer, the GBDC 3 2021 Issuer, the GBDC 3 2022 Issuer and the GBDC 3 2022-2 Issuer, collectively the Securitization Issuers. The adjusted estimate of our annualized base management fees based on actual expenses for the year ended September 30, 2025 assumes average net assets of $4,025 million and average leverage of $4,893 million, which reflects our average net assets and average net leverage as of September 30, 2025.