7. Debt

In accordance with the 1940 Act, with certain limitations, the Company is allowed to borrow amounts such that its asset coverage, as defined in the 1940 Act, is at least 150% after such borrowing. As of December 31, 2022 and 2021, the Company’s asset coverage was 188.6% and 205.4%, respectively.

Revolving Credit Facility

On August 23, 2012, the Company entered into a senior secured revolving credit agreement with Truist Bank (as a successor by merger to SunTrust Bank), as administrative agent, and J.P. Morgan Chase Bank, N.A., as syndication agent, and certain other lenders (as amended and restated, the “Revolving Credit Facility”).

As of March 31, 2022, aggregate commitments under the facility were $1.510 billion. Pursuant to an amendment to the Revolving Credit Facility dated as of April 25, 2022 (the “Twelfth Amendment”), the aggregate commitments under the facility were increased to $1.585 billion. The facility includes an uncommitted accordion feature that allows the Company, under certain circumstances, to increase the size of the facility to up to $2.0 billion.

Pursuant to the Twelfth Amendment, with respect to $1.510 billion in commitments, the revolving period, during which period the Company, subject to certain conditions, may make borrowings under the facility, was extended to April 24, 2026 and the stated maturity date was extended to April 23, 2027. For the remaining $75.0 million of commitments, (A) with respect to $25.0 million of commitments, the revolving period ends January 31, 2024 and the stated maturity is January 31, 2025 and (B) with respect to $50.0 million of commitments, the revolving period ends on February 4, 2025 and the stated maturity is February 4, 2026.

Pursuant to an amendment to the Revolving Credit Facility dated as of May 19, 2022 (the “Thirteenth Amendment”), certain non-substantive administrative and operational elements were updated.

The Company may borrow amounts in U.S. dollars or certain other permitted currencies. As of December 31, 2022, the Company had outstanding debt denominated in Australian dollars (AUD) of 69.0 million, British pounds (GBP) of 12.9 million, Canadian dollars (CAD) of 96.6 million, and Euro (EUR) of 23.4 million on its Revolving Credit Facility, included in the Outstanding Principal amount in the table above.

The Revolving Credit Facility also provides for the issuance of letters of credit up to an aggregate amount of $75 million. As of December 31, 2022 and December 31, 2021, the Company had no outstanding letters of credit issued through the Revolving Credit Facility. The amount available for borrowing under the Revolving Credit Facility is reduced by any letters of credit issued through the Revolving Credit Facility.

Amounts drawn under the Revolving Credit Facility, including amounts drawn in respect of letters of credit, bear interest at either the applicable reference rate plus an applicable credit spread adjustment, plus a margin of either 1.75% or 1.875%, or the base rate plus a margin of either 0.75% or 0.875%, in each case, based on the total amount of the borrowing base relative to the sum of the total commitments (or, if greater, the total exposure) under the Revolving Credit Facility plus certain other designated secured debt. The Company may elect either the applicable reference rate or base rate at the time of drawdown, and loans may be converted from one rate to another at any time, subject to certain conditions. The Company also pays a fee of 0.375% on undrawn amounts and, in respect of each undrawn letter of credit, a fee and interest rate equal to the then applicable margin while the letter of credit is outstanding.

The Revolving Credit Facility is guaranteed by Sixth Street SL SPV, LLC, TC Lending, LLC and Sixth Street SL Holding, LLC. The Revolving Credit Facility is secured by a perfected first-priority security interest in substantially all the portfolio investments held by the Company and each guarantor. Proceeds from borrowings may be used for general corporate purposes, including the funding of portfolio investments.

The Revolving Credit Facility includes customary events of default, as well as customary covenants, including restrictions on certain distributions and financial covenants. In accordance with the terms of the Thirteenth Amendment, the financial covenants require:

The Revolving Credit Facility also contains certain additional concentration limits in connection with the calculation of the borrowing base, based on the Obligor Asset Coverage Ratio.

Net proceeds received from the issuance of the 2022 Convertible Notes, 2023 Notes, 2024 Notes and 2026 Notes were used to pay down borrowings on the Revolving Credit Facility.

As of December 31, 2022, the Company was in compliance with the terms of the Revolving Credit Facility.

2022 Convertible Notes

In February 2017, the Company issued in a private offering $115.0 million aggregate principal amount convertible notes due August 2022 (the “2022 Convertible Notes”). The 2022 Convertible Notes were issued in a private placement only to qualified institutional buyers pursuant to Rule 144A under the Securities Act. The 2022 Convertible Notes were unsecured, and bore interest at a rate of 4.50% per year, payable semiannually. In June 2018, the Company issued in a registered public offering an additional $57.5 million aggregate principal amount of 2022 Convertible Notes. The additional 2022 Convertible Notes were issued with identical terms, and were fungible with and were part of a single series with the previously outstanding $115.0 million aggregate principal amount of the Company’s 2022 Convertible Notes issued in February 2017. The 2022 Convertible Notes matured on August 1, 2022. In connection with the offering of 2022 Convertible Notes in February 2017 and the reopening in June 2018, the Company entered into interest rate swaps to align the interest rates of its liabilities with its investment portfolio, which consists of predominately floating rate loans. The notional amount of the interest rate swaps matched the amount of principal outstanding, and matured on August 1, 2022, matching the maturity date of the 2022 Convertible Notes.

During the year ended December 31, 2020, the Company repurchased on the open market and extinguished $29.7 million in aggregate principal amount of the 2022 Convertible Notes for $29.5 million. In connection with the repurchases of the 2022 Convertible Notes, the Company entered into floating-to-fixed interest rate swaps with an aggregate notional amount equal to the amount of 2022 Convertible Notes repurchased, which had the effect of reducing the notional exposure of the fixed-to-floating interest rate swaps, which were entered into in connection with the issuance of the 2022 Convertible Notes, to match the remaining principal amount of the 2022 Convertible Notes outstanding.

Holders were entitled to convert their 2022 Convertible Notes at their option at any time prior to February 1, 2022 only under certain circumstances. On or after February 1, 2022 until the close of business on the scheduled trading day immediately preceding the maturity date, holders were entitled to convert their notes at any time.

On September 30, 2021, the Company notified the trustee and holders of the 2022 Convertible Notes that the terms of one of the conversion features had been met and the notes were eligible for conversion at the option of the holders. The notes remained convertible until October 12, 2021. During this period $42.8 million aggregate principal amount of notes were surrendered for conversion and the Company elected combination settlement. During the three months ended December 31, 2021, $42.8 million of principal of the 2022 Convertible Notes were converted and were settled with a combination of cash and 2,324,820 shares of the Company’s common stock. In connection with the settlement of the 2022 Convertible Notes, the Company entered into a floating-to-fixed interest rate swap with an aggregate notional amount equal to the amount of 2022 Convertible Notes settled, which had the effect of reducing the notional exposure of the fixed-to-floating interest rate swaps, which were entered into in connection with the issuance of the 2022 Convertible Notes, to match the remaining principal amount of the 2022 Convertible Notes outstanding.

On January 26, 2022, the Company notified the trustee and holders of the 2022 Convertible Notes that the terms of settlement for the notes at the Company’s election was a combination settlement of cash and stock to occur after the 40 day observation period described in the notes indenture. The Company elected to settle any 2022 Convertible Notes that were converted between February 1, 2022 and August 1, 2022 with a specified cash amount (as defined in the indenture governing the 2022 Convertible Notes) of $20.00 per $1,000 principal amount of the 2022 Convertible Notes and any additional amounts in stock based on the applicable conversion rate as described in the indenture.

Total interest expense in the table above does not include the effect of the interest rate swaps. During the years ended December 31, 2022, 2021 and 2020, the Company received $5.8 million, $8.9 million, and $8.4 million, respectively, and paid $4.9 million, $6.1 million, and $6.4 million, respectively, related to the quarterly settlement of its interest rate swaps. These net amounts are included in interest expense in the Company’s Consolidated Statements of Operations. Please see Note 5 for further information about the Company’s interest rate swaps.

The stated interest rate in the table above does not include the effect of the interest rate swaps. The Company’s swap-adjusted interest rate was three month LIBOR plus 2.11% (on a weighted average basis) for the 2022 Convertible Notes. Please see Note 5 for further information about the Company’s interest rate swaps.

The 2022 Convertible Notes were accounted for in accordance with ASC Topic 470-20. During the period ended March 31, 2021, the Company early adopted ASU 2020-06 and in accordance with this guidance reclassified the remaining unamortized discount on the 2022 Convertible Notes from the carrying value of the instrument to “additional paid-in capital” in the accompanying consolidated balance sheet. As a requirement under ASU 2020-06 the Company calculated diluted earnings per shares using the if-converted method which assumed full share settlement for the aggregate value of the 2022 Convertible Notes.

On August 1, 2022, the 2022 Convertible Notes matured in accordance with the governing indenture. Holders of $79.2 million aggregate principal amount of notes provided valid notice of conversion and were subject to the combination settlement method previously elected by the Company. In accordance with the settlement method, the Company issued a total of 4,360,125 shares of

common stock, or $77.6 million at the adjusted conversion price per share of $17.92. The remaining balance of the notes that were not converted into newly issued shares of common stock were settled with existing cash resources, including through utilization of the Company’s Revolving Credit Facility. The interest rate swaps associated with the principal amount of the notes outstanding were terminated on the date of maturity of the 2022 Convertible Notes.

2023 Notes

In January 2018, the Company issued $150.0 million aggregate principal amount of unsecured notes that matured on January 22, 2023 (the “2023 Notes”). The principal amount of the 2023 Notes was payable at maturity. The 2023 Notes bore interest at a rate of 4.50% per year, payable semi-annually commencing on July 22, 2018, and were redeemable in whole or in part at the Company’s option at any time at par plus a “make whole” premium. Total proceeds from the issuance of the 2023 Notes, net of underwriting discounts and offering costs, were $146.9 million. The Company used the net proceeds of the 2023 Notes to repay outstanding indebtedness under the Revolving Credit Facility.

In connection with the 2023 Notes offering, the Company entered into an interest rate swap to align the interest rates of its liabilities with the Company’s investment portfolio, which consists of predominately floating rate loans. The notional amount of the interest rate swap is $150.0 million, which matured on January 22, 2023, matching the maturity date of the 2023 Notes. As a result of the swap, the Company’s effective interest rate on the 2023 Notes was three-month LIBOR plus 1.99%. See Note 5 for further information about the Company’s interest rate swaps.

2024 Notes

In November 2019, the Company issued $300.0 million aggregate principal amount of unsecured notes that mature on November 1, 2024 (the “2024 Notes”). The principal amount of the 2024 Notes is payable at maturity. The 2024 Notes bear interest at a rate of 3.875% per year, payable semi-annually commencing on May 1, 2020, and may be redeemed in whole or in part at our option at any time at par plus a “make whole” premium. Total proceeds from the issuance of the 2024 Notes, net of underwriting discounts, offering costs and original issue discount were $292.9 million. The Company used the net proceeds of the 2024 Notes to repay outstanding indebtedness under the Revolving Credit Facility.

On February 5, 2020, the Company issued an additional $50.0 million aggregate principal amount of unsecured notes that mature on November 1, 2024. The additional 2024 Notes are a further issuance of, fungible with, rank equally in right of payment with and have the same terms (other than the issue date and the public offering price) as the initial issuance of 2024 Notes. Total proceeds from the issuance of the additional 2024 Notes, net of underwriting discounts, offering costs and original issue premium were $50.1 million. The Company used the net proceeds of the 2024 Notes to repay outstanding indebtedness under the Revolving Credit Facility.

In connection with the 2024 Notes offering and the reopening of the 2024 Notes, the Company entered into interest rate swaps to align the interest rates of its liabilities with the Company’s investment portfolio, which consists of predominately floating rate loans. The notional amount of the two interest rates swaps is $300.0 million and $50.0 million, respectively, each of which matures on November 1, 2024, matching the maturity date of the 2024 Notes. As a result of the swaps, the Company’s effective interest rate on the 2024 Notes is three-month LIBOR plus 2.28% (on a weighted average basis). The interest expense related to the 2024 Notes is offset by proceeds received from the interest rate swaps designated as a hedge. The swap adjusted interest expense is included as a component of interest expense on the Company’s Consolidated Statement of Operations. As of December 31, 2022, and 2021, the effective hedge interest rate swaps had a fair value of $(19.4) million and $4.4 million, respectively, which is offset within interest expense by an equal, but opposite, fair value change for the hedged risk on the 2024 Notes.

During the year ended December 31, 2020, the Company repurchased on the open market and extinguished $2.5 million in aggregate principal amount of the 2024 Notes for $2.4 million. These repurchases resulted in a gain on extinguishment of debt of less than $0.1 million. This gain is included in the extinguishment of debt in the accompanying consolidated statements of operations. In connection with the repurchase of the 2024 Notes, the Company entered into a floating-to-fixed interest rate swap with a notional amount equal to the amount of 2024 Notes repurchased, which had the effect of reducing the notional exposure of the fixed-to-floating interest rate swaps, which were entered into in connection with the issuance of the 2024 Notes, to match the remaining principal amount of the 2024 Notes outstanding. As a result of the swap, the Company’s effective interest rate on the outstanding 2024 Notes is three-month LIBOR plus 2.28% (on a weighted average basis).

2026 Notes

On February 3, 2021, the Company issued $300.0 million aggregate principal amount of unsecured notes that mature on August 1, 2026 (the “2026 Notes”). The principal amount of the 2026 Notes is payable at maturity. The 2026 Notes bear interest at a rate of 2.50% per year, payable semi-annually commencing on August 1, 2021, and may be redeemed in whole or in part at the Company’s option at any time at par plus a “make whole” premium. Total proceeds from the issuance of the 2026 Notes, net of underwriting discounts and estimated offering costs, were $293.7 million. The Company used the net proceeds of the 2026 Notes to repay outstanding indebtedness under the Revolving Credit Facility.

In connection with the issuance of the 2026 Notes, the Company entered into an interest rate swap to align the interest rates of its liabilities with the Company’s investment portfolio, which consists of predominately floating rate loans. The notional amount of the interest rate swap is $300.0 million, which matures on August 1, 2026, matching the maturity date of the 2026 Notes. As a result of the swap, the Company’s effective interest rate on the 2026 Notes is three-month LIBOR plus 1.91%. The interest expense related to the 2026 Notes is offset by proceeds received from the interest rate swaps designated as a hedge. The swap adjusted interest expense is included as a component of interest expense on the Company’s Consolidated Statement of Operations. For the years ended December 31, 2022 and 2021, the effective hedge interest rate swaps had a fair value of $(35.7) million and $(10.2), respectively, which is offset within interest expense by an equal, but opposite, fair value change for the hedged risk on the 2026 Notes.

Total interest expense in the table above does not include the effect of the interest rate swaps related to the 2023 Notes, 2024 Notes and 2026 Notes. During the years ended December 31, 2022, 2021 and 2020, the Company received $27.9 million, $27.2 million, and $20.2 million, respectively, and paid $31.4 million, $17.8 million and $15.7 million, respectively, related to the settlements of its interest rate swaps related to the 2023 Notes, 2024 Notes and 2026 Notes. These net amounts are included in interest expense in the Company’s consolidated statements of operations. Please see Note 5 for further information about the Company’s interest rate swaps.

The stated interest rate in the table above does not include the effect of the interest rate swaps. As of December 31, 2022 and 2021 the Company’s swap-adjusted interest rate on the 2023 Notes, 2024 Notes and 2026 Notes is three month LIBOR plus 1.99%, 2.28% (on a weighted average basis) and 1.91%, respectively.

As of December 31, 2022 and December 31, 2021, the Company was in compliance with the terms of the indentures governing the 2023 Notes, 2024 Notes and 2026 Notes.

Organization

Sixth Street Specialty Lending, Inc. (the “Company”) is a Delaware corporation formed on July 21, 2010. The Company was formed primarily to lend to, and selectively invest in, middle-market companies in the United States. The Company has elected to be regulated as a business development company (“BDC”) under the 1940 Act. In addition, for tax purposes, the Company has elected to be treated as a regulated investment company (“RIC”) under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). The Company is managed by Sixth Street Specialty Lending Advisers, LLC (the “Adviser”). On June 1, 2011, the Company formed a wholly-owned subsidiary, TC Lending, LLC, a Delaware limited liability company. On March 22, 2012, the Company formed a wholly-owned subsidiary, Sixth Street SL SPV, LLC, a Delaware limited liability company. On May 19, 2014, the Company formed a wholly-owned subsidiary, Sixth Street SL Holding, LLC, a Delaware limited liability company. On December 9, 2020, the Company formed a wholly-owned subsidiary, Sixth Street Specialty Lending Sub, LLC, a Cayman Islands limited liability company.

On March 21, 2014, the Company completed its initial public offering (“IPO”) and the Company’s shares began trading on the New York Stock Exchange (“NYSE”) under the symbol “TSLX.”

Fiscal Year End

The Company’s fiscal year ends on December 31.

Cash and Cash Equivalents

Cash and cash equivalents may consist of demand deposits, highly liquid investments (e.g., money market funds, U.S. Treasury notes, and similar type instruments) with original maturities of three months or less, and restricted cash pledged as collateral for certain centrally cleared derivative instruments. Cash and cash equivalents denominated in U.S. dollars are carried at cost, which approximates fair value. The Company deposits its cash and cash equivalents with highly-rated banking corporations and, at times, cash deposits may exceed the insured limits under applicable law.

Financial and Derivative Instruments

The Company recognizes all derivative instruments as assets or liabilities at fair value in its consolidated financial statements, pursuant to ASC Topic 815 Derivatives and Hedging, further clarified by the FASB’s issuance of the Accounting Standards Update (“ASU”) No. 2017-12, Derivatives and Hedging, which was adopted in 2019 by the Company. For all derivative instruments designated in a hedge accounting relationship, the entire change in the fair value of the hedging instrument shall be recorded in the same line item of the consolidated statements of operations as the hedged item. The Company uses certain interest rate swaps as derivative instruments to hedge the Company’s fixed rate debt, and therefore both the periodic payment and the change in fair value for the effective hedge, if applicable, will be recognized as components of interest expense in the consolidated statements of operations. For derivative contracts entered into by the Company that are not designated in a hedge accounting relationship, the Company presents changes in the fair value through current period earnings.

In the normal course of business, the Company has commitments and risks resulting from its investment transactions, which may include those involving derivative instruments. Derivative instruments are measured in terms of the notional contract amount and derive their value based upon one or more underlying instruments. While the notional amount gives some indication of the Company’s derivative activity, it generally is not exchanged, but is only used as the basis on which interest and other payments are exchanged. Derivative instruments are subject to various risks similar to non-derivative instruments including market, credit, liquidity, and operational risks. The Company manages these risks on an aggregate basis as part of its risk management process.

Derivatives, including the Company’s interest rate swaps, for which broker quotes are available are typically valued at those broker quotes.

Foreign Currency

Foreign currency amounts are translated into U.S. dollars on the following basis:

Although net assets and fair values are presented based on the applicable foreign exchange rates described above, the Company does not isolate that portion of the results of operations resulting from changes in foreign exchange rates on investments from the fluctuations arising from changes in fair values of investments held. Such fluctuations are included with the net realized and unrealized gain or loss from investments. The Company’s current approach to hedging the foreign currency exposure in its non-U.S. dollar denominated investments is primarily to borrow the par amount in local currency under the Company’s Revolving Credit Facility to fund these investments. Fluctuations arising from the translation of foreign currency borrowings are included with the net change in unrealized gains (losses) on translation of assets and liabilities in foreign currencies on the consolidated statements of operations.

Investments denominated in foreign currencies and foreign currency transactions may involve certain considerations and risks not typically associated with those of domestic origin, including unanticipated movements in the value of the foreign currency relative to the U.S. dollar.

Debt Issuance Costs

The Company records origination and other expenses related to its debt obligations as deferred financing costs, which are presented as a direct deduction from the carrying value of the related debt liability. These expenses are deferred and amortized using the effective interest method, or straight-line method, over the stated maturity of the debt obligation.

Other Income

From time to time, the Company may receive fees for services provided to portfolio companies by the Adviser. The services that the Adviser provides vary by investment, but may include syndication, structuring, diligence fees, or other service-based fees and fees for providing managerial assistance to our portfolio companies and are recognized as revenue when earned.

Reimbursement of Transaction-Related Expenses

The Company may receive reimbursement for certain transaction-related expenses in pursuing investments. Transaction-related expenses, which are expected to be reimbursed by third parties, are typically deferred until the transaction is consummated and are recorded in Prepaid expenses and other assets on the date incurred. The transaction-related costs of pursuing investments not otherwise reimbursed are borne by the Company and for successfully completed investments included as a component of the investment’s cost basis.

Cash advances received in respect of transaction-related expenses are recorded as Cash and cash equivalents with an offset to Other liabilities or Other payables to affiliates. Other liabilities or Other payables to affiliates are relieved as reimbursable expenses are incurred.

Dividends to Common Stockholders

Dividends to common stockholders are recorded on the record date. The amount to be paid out as a dividend is determined by the Board and is generally based upon the earnings estimated by the Adviser. Net realized long-term capital gains, if any, would generally be distributed at least annually, although the Company may decide to retain such capital gains.

The Company has adopted a dividend reinvestment plan that provides for reinvestment of any dividends declared in cash on behalf of stockholders, unless a stockholder elects to receive cash. As a result, if the Board authorizes, and it declares, a cash dividend, then the stockholders who have not “opted out” of the dividend reinvestment plan will have their cash dividends automatically reinvested

in additional shares of the Company’s common stock, rather than receiving the cash dividend. The Company expects to use newly issued shares to satisfy the dividend reinvestment plan.

6. Fair Value of Financial Instruments

Investments

Transfers between levels, if any, are recognized at the beginning of the quarter in which the transfers occur.

Astra Acquisition Corp. was transferred into Level 3 from Level 2 for fair value measurement purposes during the year ended December 31, 2022, as a result of changes in the observability of inputs into the security valuation for this portfolio company.

The Company typically determines the fair value of its performing Level 3 debt investments utilizing a yield analysis. In a yield analysis, a price is ascribed for each investment based upon an assessment of current and expected market yields for similar investments and risk profiles. Additional consideration is given to the expected life, portfolio company performance since close, and other terms and risks associated with an investment. Among other factors, a determinant of risk is the amount of leverage used by the portfolio company relative to the total enterprise value of the company, and the rights and remedies of our investment within each portfolio company’s capital structure.

Significant unobservable quantitative inputs typically considered in the fair value measurement of the Company’s Level 3 debt investments primarily include current market yields, including relevant market indices, but may also include quotes from brokers, dealers, and pricing services as indicated by comparable investments. If debt investments are credit impaired, an enterprise value analysis may be used to value such debt investments; however, in addition to the methods outlined above, other methods such as a liquidation or wind-down analysis may be utilized to estimate enterprise value. For the Company’s Level 3 equity investments, multiples of similar companies’ revenues, earnings before income taxes, depreciation and amortization (“EBITDA”) or some combination thereof and comparable market transactions are typically used.

Financial Instruments Not Carried at Fair Value

Debt

The fair value of the Company’s Revolving Credit Facility, which is categorized as Level 3 within the fair value hierarchy, as of December 31, 2022 and 2021, approximates its carrying value as the outstanding balance is callable at carrying value.