v3.25.4
N-2
12 Months Ended
Dec. 31, 2025
$ / shares
shares
Cover [Abstract]  
Entity Central Index Key 0001814390
Amendment Flag false
Document Type N-CSR
Entity Registrant Name Flat Rock Core Income Fund
General Description of Registrant [Abstract]  
Investment Objectives and Practices [Text Block]

INVESTMENT OBJECTIVE

Flat Rock Core Income Fund’s (the “Fund”) investment objective is the preservation of capital while generating current income from its debt investments and seeking to maximize the portfolio’s total return.

Risk Factors [Table Text Block]

8. RISK FACTORS

In the normal course of business, the Fund invests in financial instruments and enters into financial transactions where risk of potential loss exists due to such things as changes in the market (market risk) or failure or inability of the other party to a transaction to perform (credit and counterparty risk). See below for a detailed description of select principal risks. The following is not intended to be a comprehensive description of all of the potential risks associated with the Fund. The Fund’s prospectus provides a detailed discussion of the Fund’s risks.

Credit Risk: The Fund is subject to the risk that the issuer or guarantor of an obligation, or the counterparty to a transaction, may fail, or become less able, to make timely payment of interest or principal or otherwise honor its obligations or default completely. The strategies utilized by the Adviser require accurate and detailed credit analyses of issuers, and there can be no assurance that the Adviser’s analyses will be accurate or complete. The Fund may be subject to substantial losses in the event of credit deterioration or bankruptcy of one or more issuers in its portfolio.

Financial strength and solvency of an issuer are the primary factors influencing credit risk. The Fund could lose money if the issuer or guarantor of a debt security is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. Companies in which the Fund invests could deteriorate as a result of, among other factors, an adverse development in their business, a change in the competitive environment or an economic downturn. As a result, companies that the Adviser may have expected to be stable may operate, or expect to operate, at a loss or have significant variations in operating results, may require substantial additional capital to support their operations or maintain their competitive position, or may otherwise have a weak financial condition or be experiencing financial distress. In addition, inadequacy of collateral or credit enhancement for a debt obligation may affect its credit risk. Although the Fund may invest in investments that the Adviser believes are secured by specific collateral, the value of which may exceed the principal amount of the investments at the time of initial investment, there can be no assurance that the liquidation of any such collateral would satisfy the borrower’s obligation in the event of non-payment of scheduled interest or principal payments with respect to such investment, or that such collateral could be readily liquidated. In addition, in the event

of bankruptcy of a borrower, the Fund could experience delays or limitations with respect to its ability to realize the benefits of the collateral securing an investment. Under certain circumstances, collateral securing an investment may be released without the consent of the Fund.

Credit risk is typically greater for securities with ratings that are below investment grade (commonly referred to as “junk bonds”). Since the Fund can invest significantly in high-yield investments considered speculative in nature and unsecured investments, this risk may be substantial. The Fund’s right to payment and its security interest, if any, may be subordinated to the payment rights and security interests of more senior creditors. This risk may also be greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund. Changes in the actual or perceived creditworthiness of an issuer, or a downgrade or default affecting any of the Fund’s securities, could affect the Fund’s performance.

Senior Loans: The Fund pursues its investment objective by investing in a portfolio composed primarily of Senior Loans and investment vehicles, such as CLOs, BDCs or Loan Facilities. Investing in Senior Loans involves a number of significant risks. Below investment grade Senior Loans have historically experienced greater default rates than has been the case for investment grade securities. The Fund intends to achieve its investment objective by investing in a portfolio composed primarily of securities that are rated below investment grade by rating agencies, or that would be rated below investment grade if they were rated. Below investment grade securities, which are often referred to as “junk,” have predominantly speculative characteristics with respect to the issuer’s capacity to pay interest and repay principal. They may also be difficult to value and illiquid. There can be no assurance as to the levels of defaults or recoveries that may be experienced on the Fund’s investments in Senior Loans. Senior Loans in which the Fund invests may be issued by companies with limited financial resources and limited access to alternative financing. Issuers of Senior Loans may be unable to meet their obligations under their debt securities that the Fund holds. Such developments may be accompanied by deterioration in the value of collateral backing its investments. This could lead to a decline in value of the Fund’s Senior Loan investments, which could result in a decline in the Fund’s net earnings and NAV. In addition, many of the Fund’s Senior Loans are “bank loans” that may not be deemed to be “securities” for purposes of the federal securities laws. Bank loan providers may not have the protections of the anti-fraud provisions of the federal securities laws and must rely instead on contractual provisions in loan agreements and applicable common-law fraud protections.

CLO Risk: CLOs are securities backed by an underlying portfolio of loan obligations. CLOs issue classes or “tranches” that vary in risk and yield and may experience substantial losses due to actual defaults, decrease of market value due to collateral defaults and removal of subordinate tranches, market anticipation of defaults and investor aversion to CLO securities as a class. Investments in CLO securities may be riskier and less transparent than direct investments in the underlying loans and debt obligations. The risks of investing in CLOs depend largely on the tranche invested in and the type of the underlying loans in the tranche of the CLO in which the Fund invests. The tranches in a CLO vary substantially in their risk profile, and debt tranches are more senior than equity tranches. The senior tranches are relatively safer because they have first priority on the collateral in the event of default. As a result, the senior tranches of a CLO generally have a higher credit rating and offer lower coupon rates than the junior tranches, which offer higher coupon rates to compensate for their higher default risk. The CLOs in which the Fund may invest may incur, or may have already incurred, debt that is senior to the Fund’s investment. CLOs also carry risks including, but not limited to, interest rate risk and credit risk. Investments in CLOs may be subject to

certain tax provisions that could result in the Fund incurring tax or recognizing income prior to receiving cash distributions related to such income. CLOs that fail to comply with certain U.S. tax disclosure requirements may be subject to withholding requirements that could adversely affect cash flows and investment results. Any unrealized losses the Fund experiences with respect to its CLO investments may be an indication of future realized losses. Equity tranches are unrated and equity investors receive no principal payments, if any, until all debt obligations are paid.

Middle Market Risk: Investing in middle-market companies is highly speculative and involves a high degree of risk of credit loss, and therefore the Fund’s securities may not be suitable for someone with a low tolerance for risk. Middle-market companies are more likely to be considered lower grade investments, commonly called “junk,” which are either rated below investment grade by one or more nationally recognized statistical rating agencies at the time of investment or may be unrated but determined by the Adviser to be of comparable quality. Lower grade securities or comparable unrated securities are considered predominantly speculative regarding the portfolio company’s ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. These risks are likely to increase during volatile economic periods.

Global Markets Risk: The increasing interconnectivity between global economies and financial markets increases the likelihood that events or conditions in one region or financial market may adversely impact issuers in a different country, region or financial market. Securities in the Fund’s portfolio may underperform due to inflation (or expectations for inflation), interest rates, global demand for particular products or resources, natural disasters, pandemics, epidemics, terrorism, regulatory events, imposition of tariffs and governmental or quasi-governmental actions. The occurrence of global events similar to those in recent years may result in market volatility and may have long term effects on both the U.S. and global financial markets. For example, Russia’s ongoing military interventions in Ukraine have led to, and may lead to additional sanctions being levied by the United States, the European Union and other countries against Russia. Russia’s military incursion and the resulting sanctions could adversely affect global energy and financial markets and thus could affect the value of the Fund’s investments, even beyond any direct exposure the Fund may have to Russian issuers or the adjoining geographic regions. The extent and duration of the military action, sanctions and resulting market disruptions are impossible to predict, but could be substantial. Any such disruptions caused by Russian military action or resulting sanctions may magnify the impact of other risks. In addition, the Israel-Hamas conflict as well as the potential risk for a wider conflict could negatively affect financial markets. Geopolitical tensions introduce uncertainty into global markets. This conflict could disrupt regional trade and supply chains, potentially affecting U.S. businesses with exposure to the region. Additionally, the Middle East plays a pivotal role in the global energy sector, and prolonged instability could impact oil prices, leading to increased costs for businesses and consumers. Furthermore, the U.S.’s diplomatic ties and commitments in the region mean that it might become more directly involved, either diplomatically or militarily, diverting attention and resources. These and any related events could significantly impact the Fund’s performance and the value of an investment in the Fund, even if the Fund does not have direct exposure. It is not known how long such impacts, or any future impacts of other significant events described above, will or would last, but there could be a prolonged period of global economic slowdown, which may impact your Fund investment.

Valuation Risk: Most of the Fund’s investments are not traded on national securities exchanges, and the Fund does not have the benefit of market quotations or other pricing data from such an exchange. Certain of the Fund’s investments will have the benefit of third-party bid-ask quotations. With respect to investments for which pricing data is not readily available or when such pricing data is deemed not to represent fair value, the Fund’s Board determines fair value using the valuation procedures approved by the Board. There is no single standard for determining fair value in good faith. As a result, determining fair value requires that judgment be applied to the specific facts and circumstances of each portfolio investment while employing a consistently applied valuation process for the types of investments the Fund makes.

Interest Rate Risk: Interest rate sensitivity refers to the change in earnings that may result from changes in the level of interest rates. The Fund intends to fund portions of its investments with borrowings, and at such time, its net investment income will be affected by the difference between the rate at which it invests and the rate at which it borrows. Accordingly, the Fund cannot assure that a significant change in market interest rates will not have a material adverse effect on its net investment income.

NAV Per Share | $ / shares $ 19.62
Capital Stock, Long-Term Debt, and Other Securities [Abstract]  
Capital Stock [Table Text Block]

10. MANDATORILY REDEEMABLE PREFERRED STOCK

At December 31, 2025, the Fund issued and had outstanding 1,000 Series A Term Preferred Shares. The Series A Term Preferred Shares have a liquidation preference of $10,000 per share plus accrued and unpaid dividends (whether or not declared). The Fund issued 1,000 Series A Term Preferred Shares on September 30, 2021. The Series A Term Preferred Shares are entitled to a dividend at a rate of 4.00% per year based on the $10,000 liquidation preference before the common stock is entitled to receive any dividends. The Series A Term Preferred Shares are redeemable at $10,000 per share plus accrued and

unpaid dividends (whether or not declared) exclusively at the Fund’s option upon written notice. Debt issuance costs related to Series A Preferred Shares of $200,000 are deferred and amortized over the period the Series A Term Preferred Shares are outstanding.

Series

 

Mandatory
Redemption
Date

 

Annual
Dividend
Rate

 

Shares
Outstanding

 

Aggregate
Liquidation
Preference

 

Unamortized
Deferred
Issuance
Costs

 

Carrying
Value of
Preferred
Shares

 

Fair Value
as of
December 31,
2025

Series A Term Preferred Shares

 

September 15, 2026

 

4.00%

 

1,000

 

$

10,000,000

 

$

5,432

 

$

9,994,568

 

$

9,917,038

This fair value is based on Level 3 inputs under the fair value hierarchy. The following table summarizes the valuation techniques and significant unobservable inputs that are used to estimate the fair value for the Series A Term Preferred Shares. The Series A Term Preferred Shares are presented on the Consolidated Statement of Assets and Liabilities at the aggregate liquidation preference, net of deferred financing costs.

Assets

 

Fair Value
as of
December 31,
2025

 

Valuation
Techniques

 

Unobservable
Inputs

 

Range/Weighted
Average
(1)

 

Impact to
Valuation
from an
Increase in
Input
(2)

Series A Term Preferred Shares

 

$

9,917,038

 

Income Approach (Discounted Cash Flow Model)

 

Discount Rates

 

5.10% – 6.20%/5.57%

 

Decrease

(1)    Weighted averages are calculated based on fair value of investments.

(2)    The impact on fair value measurement of an increase in each unobservable input is in isolation.

Security Title [Text Block] MANDATORILY REDEEMABLE PREFERRED STOCK
Security Dividends [Text Block] The Series A Term Preferred Shares have a liquidation preference of $10,000 per share plus accrued and unpaid dividends (whether or not declared).
Security Liquidation Rights [Text Block] The Series A Term Preferred Shares are entitled to a dividend at a rate of 4.00% per year based on the $10,000 liquidation preference before the common stock is entitled to receive any dividends.
Long Term Debt [Table Text Block]

9. BORROWINGS

The Fund maintains an $85 million revolving line of credit (the “Credit Facility”) through a special purpose wholly-owned subsidiary, FRC Funding, with certain financial institutions as lenders (“Lenders”). These Lenders include Cadence Bank, N.A. (“Cadence”) as the administrative agent, as well as Georgia Banking Company (“GBC”), Synovus Bank (“Synovus”), and Woodforest National Bank (“Woodforest”). The Loan Agreement for the Credit Facility, by and between the Fund and the Lenders (the “Loan Agreement”), expires on July 22, 2030.

As of December 31, 2025, the Fund had drawn down $43,451,895 from the Credit Facility and the maximum borrowing outstanding during the year was $72,993,373. The balance drawn from the Credit Facility is inclusive of $243,750 of upfront fees in addition to the principal balance. The Fund is charged an interest rate of 2.70% above the 1-month Secured Overnight Financing Rate (“SOFR”) plus 0.11448%. The Fund is charged a fee on the average daily unused balance of the Credit Facility of 0.40%. Pursuant to the terms of the Loan Agreement, the Fund granted Cadence, for the benefit of the Lenders, a security interest and a lien in substantially all of FRC Funding’s assets. The average balance outstanding and weighted average interest rate for the fiscal year ended December 31, 2025, was $53,747,598 and 7.06%, respectively.

Outstanding Security, Title [Text Block] Shares of beneficial interest outstanding
Outstanding Security, Held [Shares] | shares 15,702,526
Credit Risks [Member]  
General Description of Registrant [Abstract]  
Risk [Text Block]

Credit Risk: The Fund is subject to the risk that the issuer or guarantor of an obligation, or the counterparty to a transaction, may fail, or become less able, to make timely payment of interest or principal or otherwise honor its obligations or default completely. The strategies utilized by the Adviser require accurate and detailed credit analyses of issuers, and there can be no assurance that the Adviser’s analyses will be accurate or complete. The Fund may be subject to substantial losses in the event of credit deterioration or bankruptcy of one or more issuers in its portfolio.

Financial strength and solvency of an issuer are the primary factors influencing credit risk. The Fund could lose money if the issuer or guarantor of a debt security is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. Companies in which the Fund invests could deteriorate as a result of, among other factors, an adverse development in their business, a change in the competitive environment or an economic downturn. As a result, companies that the Adviser may have expected to be stable may operate, or expect to operate, at a loss or have significant variations in operating results, may require substantial additional capital to support their operations or maintain their competitive position, or may otherwise have a weak financial condition or be experiencing financial distress. In addition, inadequacy of collateral or credit enhancement for a debt obligation may affect its credit risk. Although the Fund may invest in investments that the Adviser believes are secured by specific collateral, the value of which may exceed the principal amount of the investments at the time of initial investment, there can be no assurance that the liquidation of any such collateral would satisfy the borrower’s obligation in the event of non-payment of scheduled interest or principal payments with respect to such investment, or that such collateral could be readily liquidated. In addition, in the event

of bankruptcy of a borrower, the Fund could experience delays or limitations with respect to its ability to realize the benefits of the collateral securing an investment. Under certain circumstances, collateral securing an investment may be released without the consent of the Fund.

Credit risk is typically greater for securities with ratings that are below investment grade (commonly referred to as “junk bonds”). Since the Fund can invest significantly in high-yield investments considered speculative in nature and unsecured investments, this risk may be substantial. The Fund’s right to payment and its security interest, if any, may be subordinated to the payment rights and security interests of more senior creditors. This risk may also be greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund. Changes in the actual or perceived creditworthiness of an issuer, or a downgrade or default affecting any of the Fund’s securities, could affect the Fund’s performance.

Senior Loans [Member]  
General Description of Registrant [Abstract]  
Risk [Text Block]

Senior Loans: The Fund pursues its investment objective by investing in a portfolio composed primarily of Senior Loans and investment vehicles, such as CLOs, BDCs or Loan Facilities. Investing in Senior Loans involves a number of significant risks. Below investment grade Senior Loans have historically experienced greater default rates than has been the case for investment grade securities. The Fund intends to achieve its investment objective by investing in a portfolio composed primarily of securities that are rated below investment grade by rating agencies, or that would be rated below investment grade if they were rated. Below investment grade securities, which are often referred to as “junk,” have predominantly speculative characteristics with respect to the issuer’s capacity to pay interest and repay principal. They may also be difficult to value and illiquid. There can be no assurance as to the levels of defaults or recoveries that may be experienced on the Fund’s investments in Senior Loans. Senior Loans in which the Fund invests may be issued by companies with limited financial resources and limited access to alternative financing. Issuers of Senior Loans may be unable to meet their obligations under their debt securities that the Fund holds. Such developments may be accompanied by deterioration in the value of collateral backing its investments. This could lead to a decline in value of the Fund’s Senior Loan investments, which could result in a decline in the Fund’s net earnings and NAV. In addition, many of the Fund’s Senior Loans are “bank loans” that may not be deemed to be “securities” for purposes of the federal securities laws. Bank loan providers may not have the protections of the anti-fraud provisions of the federal securities laws and must rely instead on contractual provisions in loan agreements and applicable common-law fraud protections.

CLO Risk [Member]  
General Description of Registrant [Abstract]  
Risk [Text Block]

CLO Risk: CLOs are securities backed by an underlying portfolio of loan obligations. CLOs issue classes or “tranches” that vary in risk and yield and may experience substantial losses due to actual defaults, decrease of market value due to collateral defaults and removal of subordinate tranches, market anticipation of defaults and investor aversion to CLO securities as a class. Investments in CLO securities may be riskier and less transparent than direct investments in the underlying loans and debt obligations. The risks of investing in CLOs depend largely on the tranche invested in and the type of the underlying loans in the tranche of the CLO in which the Fund invests. The tranches in a CLO vary substantially in their risk profile, and debt tranches are more senior than equity tranches. The senior tranches are relatively safer because they have first priority on the collateral in the event of default. As a result, the senior tranches of a CLO generally have a higher credit rating and offer lower coupon rates than the junior tranches, which offer higher coupon rates to compensate for their higher default risk. The CLOs in which the Fund may invest may incur, or may have already incurred, debt that is senior to the Fund’s investment. CLOs also carry risks including, but not limited to, interest rate risk and credit risk. Investments in CLOs may be subject to

certain tax provisions that could result in the Fund incurring tax or recognizing income prior to receiving cash distributions related to such income. CLOs that fail to comply with certain U.S. tax disclosure requirements may be subject to withholding requirements that could adversely affect cash flows and investment results. Any unrealized losses the Fund experiences with respect to its CLO investments may be an indication of future realized losses. Equity tranches are unrated and equity investors receive no principal payments, if any, until all debt obligations are paid.

Middle Market Risk [Member]  
General Description of Registrant [Abstract]  
Risk [Text Block]

Middle Market Risk: Investing in middle-market companies is highly speculative and involves a high degree of risk of credit loss, and therefore the Fund’s securities may not be suitable for someone with a low tolerance for risk. Middle-market companies are more likely to be considered lower grade investments, commonly called “junk,” which are either rated below investment grade by one or more nationally recognized statistical rating agencies at the time of investment or may be unrated but determined by the Adviser to be of comparable quality. Lower grade securities or comparable unrated securities are considered predominantly speculative regarding the portfolio company’s ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. These risks are likely to increase during volatile economic periods.

Global Markets Risk [Member]  
General Description of Registrant [Abstract]  
Risk [Text Block]

Global Markets Risk: The increasing interconnectivity between global economies and financial markets increases the likelihood that events or conditions in one region or financial market may adversely impact issuers in a different country, region or financial market. Securities in the Fund’s portfolio may underperform due to inflation (or expectations for inflation), interest rates, global demand for particular products or resources, natural disasters, pandemics, epidemics, terrorism, regulatory events, imposition of tariffs and governmental or quasi-governmental actions. The occurrence of global events similar to those in recent years may result in market volatility and may have long term effects on both the U.S. and global financial markets. For example, Russia’s ongoing military interventions in Ukraine have led to, and may lead to additional sanctions being levied by the United States, the European Union and other countries against Russia. Russia’s military incursion and the resulting sanctions could adversely affect global energy and financial markets and thus could affect the value of the Fund’s investments, even beyond any direct exposure the Fund may have to Russian issuers or the adjoining geographic regions. The extent and duration of the military action, sanctions and resulting market disruptions are impossible to predict, but could be substantial. Any such disruptions caused by Russian military action or resulting sanctions may magnify the impact of other risks. In addition, the Israel-Hamas conflict as well as the potential risk for a wider conflict could negatively affect financial markets. Geopolitical tensions introduce uncertainty into global markets. This conflict could disrupt regional trade and supply chains, potentially affecting U.S. businesses with exposure to the region. Additionally, the Middle East plays a pivotal role in the global energy sector, and prolonged instability could impact oil prices, leading to increased costs for businesses and consumers. Furthermore, the U.S.’s diplomatic ties and commitments in the region mean that it might become more directly involved, either diplomatically or militarily, diverting attention and resources. These and any related events could significantly impact the Fund’s performance and the value of an investment in the Fund, even if the Fund does not have direct exposure. It is not known how long such impacts, or any future impacts of other significant events described above, will or would last, but there could be a prolonged period of global economic slowdown, which may impact your Fund investment.

Valuation Risk [Member]  
General Description of Registrant [Abstract]  
Risk [Text Block]

Valuation Risk: Most of the Fund’s investments are not traded on national securities exchanges, and the Fund does not have the benefit of market quotations or other pricing data from such an exchange. Certain of the Fund’s investments will have the benefit of third-party bid-ask quotations. With respect to investments for which pricing data is not readily available or when such pricing data is deemed not to represent fair value, the Fund’s Board determines fair value using the valuation procedures approved by the Board. There is no single standard for determining fair value in good faith. As a result, determining fair value requires that judgment be applied to the specific facts and circumstances of each portfolio investment while employing a consistently applied valuation process for the types of investments the Fund makes.

Interest Rate Risk [Member]  
General Description of Registrant [Abstract]  
Risk [Text Block]

Interest Rate Risk: Interest rate sensitivity refers to the change in earnings that may result from changes in the level of interest rates. The Fund intends to fund portions of its investments with borrowings, and at such time, its net investment income will be affected by the difference between the rate at which it invests and the rate at which it borrows. Accordingly, the Fund cannot assure that a significant change in market interest rates will not have a material adverse effect on its net investment income.