Significant Accounting Policies

12 Months Ended

Dec. 31, 2025

ISQ Open Infrastructure Company LLC - Series I [Member]

Significant Accounting Policies [Line Items]

SIGNIFICANT ACCOUNTING POLICIES

2. SIGNIFICANT ACCOUNTING POLICIES

Basis of Accounting— The consolidated financial statements were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and are presented in United States dollars. The Company’s fiscal year end is December 31.

Series I consolidated financial statements are prepared using the accounting and reporting guidance under Financial Accounting Standards Board Accounting Standards Codification (“FASB”) Accounting Standards Codification (“ASC”) 946, Financial Services—Investment Companies. Series I and Series II qualify as investment companies solely for accounting purposes and not for any other purpose. Series I and Series II are not registered, and are not required to be registered, as investment companies under the Investment Company Act. Series I and Series II follow the significant accounting policies described below.

Basis of Presentation— Series I and Series II are treated as distinct entities under the LLC Act and for U.S. federal income tax purposes, each with its own segregated assets, liabilities, and expenses. If any expenses are incurred on behalf of or for the benefit of either Series, the Manager will allocate those expenses among Series based on the relative size of each Series’ investment in the relevant activity or entity, the net asset value of each Series, or another method the Manager, in good faith, deems fair and reasonable.

Basis of Consolidation— As provided under Regulation S-X and ASC 946, the Company will generally not consolidate its investments in a company other than a wholly owned investment company or controlled operating company whose business consists of providing services to Series I. Accordingly, Series I consolidated the financial position and results of operations of its wholly-owned subsidiary, the Blocker. All significant intercompany transactions and balances have been eliminated in consolidation.

Use of Estimates— The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions, in particular the fair value of investments, that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the amounts of income and expenses during the reporting period. Management believes that the estimates utilized in preparing the consolidated financial statements are reasonable and prudent; however, actual results could differ from those estimates, and such differences could be material to Series I.

Cash and Cash Equivalents— Cash and cash equivalents include cash on hand, cash held in banks and money market funds with financial institutions with maturities of three months or fewer at the time of acquisition. As of December 31, 2025, Series I held cash of $7,000 and no cash equivalents.

Organizational and Offering Expenses— Organizational expenses are expensed as incurred. Organizational expenses consist of costs incurred to establish Series I and enable it legally to do business. Organizational expenses will be paid by the Manager, subject to potential recoupment as described in Note 3. For the period from the Funding Date to December 31, 2025, Series I incurred organizational expenses of $328,197.

Offering expenses include registration fees and legal fees regarding the preparation of the general form of registration of securities. Offering expenses are accounted for as deferred costs until operations begin. Offering expenses are then amortized over the first twelve months of operations on a straight-line basis. As of December 31, 2025, Series I incurred cumulative offering costs of $221,784. For the period from March 28, 2025 to December 31, 2025, Series I amortized $48,587 of deferred offering costs.

Distribution Fees and Servicing Fees— Series I invests in Series II. As a result, holders of any class of Series I Shares will indirectly bear their proportional share of the Distribution and Servicing fee that are charged at the Series II level. These fees are not charged again at the Series I level, but Series I’s share of such fees is allocated to it through its investment in Series II, as further described in the Fourth Amended and Restated Limited Liability Company Agreement of the Company (as amended from time to time, the “LLC Agreement”).

Investments, At Fair Value— The investment valuation policy of Series I is to value its financial instruments at fair value. Series I records its investment in Series II at fair value based on its proportionate interest in the net assets of Series II. Valuation of assets held by Series II is discussed in Note 2 of Series II’s Notes to Consolidated Financial Statements.

Investment in Series II— On a monthly basis, Series I, records its proportionate share of the income, expenses, realized gains and losses and change in unrealized gains and losses of Series II. In addition, Series I accrues its own income and expenses. As of December 31, 2025, Series I owned 22.5% of the net assets of Series II. The performance of Series I is directly impacted by the performance of Series II. The notes to Series II consolidated financial statements are attached to Series I consolidated financial statements and are an integral part of these consolidated financial statements.

Income Taxes— Series I operates so that it will qualify to be treated as a partnership for U.S. federal income tax purposes under the Internal Revenue Code. An entity that is treated as a partnership for U.S. federal tax purposes generally incurs no U.S. federal income tax liability. Instead, each partner is generally required to take into account its allocable share of items of income, gain, loss, deduction, or credit of the entity in computing its U.S. federal income tax liability, regardless of whether cash distributions are made. A partnership, such as each Series, may nonetheless be taxed as a corporation if it is a publicly traded partnership, unless it meets the qualifying income exception. The qualifying income exception applies with respect to a publicly traded partnership if (i) at least 90% of such partnership’s gross income for each taxable year consists of “qualifying income” and (ii) the partnership would not be required to register under the Investment Company Act if it were a U.S. corporation. Qualifying income includes certain interest income, dividends, real property rents, gains from the sale or other disposition of real property, and any gain from the sale or disposition of a capital asset or other property held for the production of income that otherwise constitutes qualifying income. Each Series is managed such that it will meet the qualifying income exception in each taxable year. If either Series were recharacterized as a corporation for federal income tax purposes by not meeting the qualifying income exception, the holders of interest in that Series would then be treated as stockholders in a corporation, and the Series would become taxable as a corporation for U.S. federal income tax purposes. Further, each Series would be subject to U.S. corporate income tax on its net taxable income. In addition, each Series operates, in part, through subsidiaries that may be treated as corporations for U.S. and non-U.S. tax purposes and therefore may be subject to current and deferred U.S. federal, state and/or local income taxes at the subsidiary level.

Calculation of Net Asset Value— Net asset value (“NAV”) under GAAP by share class is calculated by subtracting total liabilities for each class from the total carrying amount of all assets for that class, which includes the fair value of investments. At the end of each month, any change in our NAV (whether an increase or decrease) is allocated among each share class based on the relative percentage of the previous aggregate NAV for each share class, adjusted for issuances of shares that were effective on the first calendar day of such month and redemptions that were effective on the last calendar day of such month. Net asset value per share for each class is calculated by dividing the net asset value for that class by the total number of outstanding shares of that class on the reporting date.

The Manager is ultimately responsible for the Company’s NAV calculations.

Due to/Due from Manager— Balances due to or due from the Manager represent amounts payable or receivable arising from reimbursable expenses, fee waivers, expense support arrangements, or other related-party transactions. These amounts are recorded at their contractual amount and are settled in the normal course of business. Amounts due to the Manager are classified as liabilities, and amounts due from the Manager are classified as assets in the Consolidated Statement of Assets and Liabilities.

Segment Reporting— The Company operates through a single operating and reporting segment with a primary objective of generating attractive risk-adjusted returns consisting of both current income and long-term capital appreciation. The chief operating decision maker (“CODM”) is comprised of the Company’s Chief Executive Officer and Chief Investment Officer (the “Principal Committee”) which assesses the performance and makes operating decisions of the Company on a consolidated basis. The CODM has concluded that the Company operates as a single operating segment because the Company has a single investment strategy against which the CODM assesses the Company’s performance. In addition to other metrics, the CODM uses net increase (decrease) in net assets resulting from operations as a key metric to assess the Company’s performance. As the Company’s investment operations comprise a single reporting segment, the segment assets are the same assets that are reported in the Consolidated Statement of Assets and Liabilities and significant segment expenses are the same as those listed in the Consolidated Statements of Operations.

ISQ Open Infrastructure Company LLC - Series II [Member]

Significant Accounting Policies [Line Items]

SIGNIFICANT ACCOUNTING POLICIES

2. SIGNIFICANT ACCOUNTING POLICIES

Basis of Accounting— The consolidated financial statements were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and are presented in United States dollars. The Company’s fiscal year end is December 31.

Series II consolidated financial statements are prepared using the accounting and reporting guidance under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 946, Financial Services—Investment Companies. Series I and Series II qualify as investment companies solely for accounting purposes and not for any other purpose. Series I and Series II are not registered, and are not required to be registered, as investment companies under the Investment Company Act. Series I and Series II follow the significant accounting policies described below.

Basis of Presentation— Series I and Series II are treated as distinct entities under the LLC Act and for U.S. federal income tax purposes, each with its own segregated assets, liabilities, and expenses. If any expenses are incurred on behalf of or for the benefit of either Series, the Manager will allocate those expenses among Series based on the relative size of each Series’ investment in the relevant activity or entity, the net asset value of each Series, or another method the Manager, in good faith, deems fair and reasonable.

Basis of Consolidation— As provided under Regulation S-X and ASC 946, Series II will generally not consolidate its investments in a company other than a wholly owned investment company or controlled operating company whose business consists of providing services to Series II. Accordingly, Series II consolidated the financial position and results of operations of its wholly owned subsidiaries. All significant intercompany transactions and balances have been eliminated in consolidation.

Use of Estimates— The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions, in particular the fair value of investments, that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the amounts of income and expenses during the reporting period. Management believes that the estimates utilized in preparing the consolidated financial statements are reasonable and prudent; however, actual results could differ from those estimates, and such differences could be material to Series II.

Cash and Cash Equivalents— Cash and cash equivalents include cash on hand, cash held in banks and money market funds with financial institutions with maturities of three months or fewer at the time of acquisition. As of December 31, 2025, Series II held cash equivalents of $2,180,513.

Organizational and Offering Expenses— Organizational expenses are expensed as incurred. Organizational expenses consist of costs incurred to establish Series II and enable it legally to do business. Organizational expenses will be paid by the Manager, subject to potential recoupment as described in Note 6. For the period from the Funding Date to December 31, 2025, Series II incurred organizational expenses of $2,867,509.

Offering expenses include registration fees and legal fees regarding the preparation of the general form of registration of securities. Offering expenses are accounted for as deferred costs until operations begin. Offering expenses are then amortized over the first twelve months of operations on a straight-line basis. For the period from March 28, 2025 to December 31, 2025, Series II incurred offering expenses of $1,734,837. For the period ended December 31, 2025, Series II amortized $411,159 of deferred offering expenses.

Distribution Fees and Servicing Fees— — Series II pays the applicable selling agents ongoing servicing fees (the “Servicing Fees”) of 0.85% of NAV per annum for Class F-S Shares, Class F-S_TE Shares, and Class S_TE Shares, 0.50% of NAV per annum for Class F-J Shares, Class F-J_TE and Class J_TE Shares, and 0.25% of NAV per annum for Class F-D_TE Shares, and Class D_TE Shares, payable monthly in arrears, as they become contractually due.

Class F-I Shares, Class F-I_TE Shares, Class I_TE Shares, Class E Shares, and Class E_TE Shares do not incur Servicing Fees. Such Servicing Fees are calculated based on Series II’s transactional net asset value, which is the price at which Series II sells and redeems its Shares.

All or a portion of the Servicing Fee may be used to pay for sub-transfer agency, platform, sub-accounting and certain other administrative services.

Under GAAP, Series II accrues the cost of the Servicing Fees and Distribution Fees as an offering cost at the time Series II sells the applicable classes of Shares and amortizes such costs over the estimated life of the Shares. As of December 31, 2025, Series II has accrued $2,805,542 of Servicing Fees payable to the selling agents related to the applicable classes of Shares sold.

Investments, at Fair Value— ASC 820, Fair Value Measurement, defines fair value, establishes a framework for measuring fair value in accordance with U.S. GAAP and expands disclosures about fair value. Series II recognizes and accounts for its assets (including the Infrastructure Assets) at fair value. The fair value of the assets does not reflect transaction costs that may be incurred upon disposition of the assets.

Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Where available, fair value is based on observable market prices or parameters or derived from such prices or parameters. Where observable prices or inputs are not available, valuation models are applied. These valuation techniques involve some level of management estimation and judgment, the degree of which is dependent on the price transparency for the instruments or market and the instruments’ complexity for disclosure purposes.

Assets and liabilities recorded at fair value on the Consolidated Statement of Assets and Liabilities are categorized based upon the level of judgment associated with the inputs used to measure their value. Hierarchical levels, as defined under U.S. GAAP, are directly related to the amount of subjectivity associated with the inputs to fair valuations of these assets and liabilities, and are as follows:

Level 1— inputs are observable market inputs that reflect quoted prices for identical securities in active markets that the entity has the ability to access at the measurement date.

Level 2— inputs are observable market inputs other than quoted prices for identical assets in active markets the entity has the ability to access at the measurement date.

Level 3— inputs are unobservable markets inputs, for example, inputs derived through extrapolation or interpolation that are not able to be corroborated by observable market data.

A significant decrease in the volume and level of activity for the asset or liability is an indication that transactions or quoted prices may not be representative of fair value because in such market conditions there may be increased instances of transactions that are not orderly. In those circumstances, further analysis of transactions or quoted prices is needed, and an adjustment to the transactions or quoted prices may be necessary to estimate fair value.

The board of directors (the “Board”) is responsible for overseeing the valuation of Series II’s investments at fair value as determined in good faith pursuant to Series II’s valuation policy. The Board has designated the Manager as Series II’s valuation designee, with day-to-day responsibility for implementing the portfolio valuation process set forth in Series II’s valuation policy.

There is no single standard for determining fair values of assets that do not have a readily available market price and, in many cases, such fair values may be best expressed as a range of fair values from which a single estimate may be derived in good faith. As a result, determining fair value requires that judgment be applied to the specific facts and circumstances of each acquisition while employing a valuation process that is consistently followed. Determinations of fair value involve subjective judgments and estimates.

When making fair value determinations for Infrastructure Assets that do not have readily available market prices, the Manager considers industry-accepted valuation methodologies, primarily consisting of an income approach and market approach. The income approach derives fair value based on the present value of cash flows that a business or asset is expected to generate in the future. The market approach relies upon valuations for comparable companies, transactions or assets, and includes making judgments about which companies, transactions, or assets are comparable. A blend of approaches may be relied upon in arriving at an estimate of fair value, though there may be instances where it is more appropriate to utilize one approach. It is common to use only the income approach for Infrastructure Assets. The Manager also considers a range of additional factors that it deems relevant, including a potential sale of an Infrastructure Asset, macro and local market conditions, industry information and the Infrastructure Asset’s historical and projected financial data.

Infrastructure Assets will generally be valued at transaction price initially; however, to the extent the Manager does not believe an Infrastructure Asset’s transaction price reflects the current market value, the Manager will adjust such valuation. When making fair value determinations for Infrastructure Assets, the Manager will update the prior month-end valuations by incorporating the then current market comparables and discount rate inputs, any material changes to the Infrastructure Assets financial performance since the valuation date, as well as any cash flow activity related to the Infrastructure Assets during the month. The Manager values Infrastructure Assets using the valuation methodology it deems most appropriate and consistent with widely recognized valuation methodologies and market conditions.

When making fair value determinations for assets that do not have a reliable readily available market price, the Manager will engage one or more independent valuation firms to provide positive assurance regarding the reasonableness of such valuations as of the relevant measurement date. However, the Manager is ultimately responsible for determining the fair value of all applicable investments in good faith in accordance with Series II’s valuation policies and procedures.

Because assets are valued as of a specified valuation date, events occurring subsequent to that date will not be reflected in Series II’s valuations. However, if information indicating a condition that existed at the valuation date becomes available subsequent to the valuation date and before financial information is publicly released, it will be evaluated to determine whether it would have a material impact requiring adjustment of the final valuation.

At least annually, the Manager reviews the appropriateness of Series II’s valuation policies and procedures and will recommend any proposed changes to the Board. From time to time, the Board and the Manager may adopt changes to the valuation policies and procedures if they determine that such changes are likely to result in a more accurate reflection of estimated fair value.

Net Realized Gains or Losses and Net Change in Unrealized Appreciation (Depreciation) on Investments and Derivatives— Without regard to unrealized appreciation (depreciation) previously recognized, realized gains or losses will be measured as the difference between the net proceeds from the sale, repayment, or disposal of an asset and the adjusted cost basis of the asset. Net change in unrealized appreciation (depreciation) will reflect the change in investment values during the reporting period, including the reversal of any previously recorded unrealized appreciation (depreciation) when gains or losses are realized.

Income and Expense Recognition— Interest income is recognized on the accrual basis. Series II records dividend income and accrues interest income from private securities pursuant to the terms of the respective investment, unless, in the case of dividend income, the General Partner determines that the portfolio company does not have positive earnings in which case such dividend income is treated as a return of capital. The Company records unrealized appreciation or depreciation on their investments based upon the change in fair value of investments. Realized gains and losses on the sale of investments are recorded on the trade date basis using the specific identification method. Expenses are recorded as incurred. Interest and dividend income are recorded net of any withholding taxes. Interest income is not accrued when collection appears unlikely.

Income Taxes— Series II operates so that it will qualify to be treated as a partnership for U.S. federal income tax purposes under the Internal Revenue Code. An entity that is treated as a partnership for U.S. federal tax purposes generally incurs no U.S. federal income tax liability. Instead, each partner is generally required to take into account its allocable share of items of income, gain, loss, deduction, or credit of the entity in computing its U.S. federal income tax liability, regardless of whether cash distributions are made. A partnership, such as each Series, may nonetheless be taxed as a corporation if it is a publicly traded partnership, unless it meets the qualifying income exception. The qualifying income exception applies with respect to a publicly traded partnership if (i) at least 90% of such partnership’s gross income for each taxable year consists of “qualifying income” and (ii) the partnership would not be required to register under the Investment Company Act if it were a U.S. corporation. Qualifying income includes certain interest income, dividends, real property rents, gains from the sale or other disposition of real property, and any gain from the sale or disposition of a capital asset or other property held for the production of income that otherwise constitutes qualifying income. Each Series is managed such that it will meet the qualifying income exception in each taxable year. If either Series were recharacterized as a corporation for federal income tax purposes by not meeting the qualifying income exception, the holders of interest in that Series would then be treated as stockholders in a corporation, and the Series would become taxable as a corporation for U.S. federal income tax purposes. Further, each Series would be subject to U.S. corporate income tax on its net taxable income. In addition, each Series operates, in part, through subsidiaries that may be treated as corporations for U.S. and non-U.S. tax purposes and therefore may be subject to current and deferred U.S. federal, state and/or local income taxes at the subsidiary level.

Deferred Income Taxes— Income taxes are accounted for using the asset and liability method of accounting. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of differences between the carrying amounts of assets and liabilities and their respective tax basis, using tax rates in effect for the year in which the differences are expected to reverse. The effect on deferred assets and liabilities of a change in tax rates is recognized in the Consolidated Statements of Operations in the period when the change is enacted.

Deferred tax assets are reduced by a valuation allowance when, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. When evaluating the realizability of the deferred tax assets, all evidence, both positive and negative, is considered. Items considered when evaluating the need for a valuation allowance include the ability to carry back losses, future reversals of existing temporary differences, tax planning strategies, and expectations of future earnings.

Uncertain Tax Positions— Series II analyzes its tax filing positions in all of the U.S. federal, state and local tax jurisdictions and foreign tax jurisdictions where it is required to file income tax returns, as well as for all open tax years in these jurisdictions. If, based on this analysis, the Company determines that uncertainties in tax positions exist, a reserve is established. The reserve for uncertain tax positions is recorded in Taxes Payable in the accompanying Consolidated Statements of Assets and Liabilities. Series II recognizes accrued interest and penalties related to uncertain tax positions within the provision for income taxes in the Consolidated Statements of Operations. Series II records uncertain tax positions on the basis of a two-step process: (a) determination is made whether it is more likely than not that the tax positions will be sustained based on the technical merits of the position and (b) those tax positions that meet the more-likely-than-not threshold are recognized as the largest amount of tax benefit that is greater than 50 percent likely to be realized upon ultimate settlement with the related tax authority.

Calculation of Net Asset Value— Net asset value (“NAV”) under GAAP by share class is calculated by subtracting total liabilities for each class from the total carrying amount of all assets for that class, which includes the fair value of investments. At the end of each month, any change in our NAV (whether an increase or decrease) is allocated among each share class based on the relative percentage of the previous aggregate NAV for each share class, adjusted for issuances of shares that were effective on the first calendar day of such month and redemptions that were effective on the last calendar day of such month. Net asset value per share for each class is calculated by dividing the net asset value for that class by the total number of outstanding shares of that class on the reporting date.

The Manager is ultimately responsible for the Company’s NAV calculations.

Borrowings— Series II records amounts drawn under its line of credit as borrowings within the Consolidated Statement of Assets and Liabilities. Borrowings under the line of credit are initially recognized at cost, which represents the proceeds received, and are subsequently carried at amortized cost. Interest accrues at the contractual interest rate applicable under the Credit Agreement (as defined below), which is generally based on the Secured Overnight Financing Rate (“SOFR”) plus a stated margin, or such other base rate as defined under the terms of the facility.

Due to/Due from Manager— Balances due to or due from the Manager represent amounts payable or receivable arising from reimbursable expenses, fee waivers, expense support arrangements, or other related-party transactions. These amounts are recorded at their contractual amount and are settled in the normal course of business. Amounts due to the Manager are classified as liabilities, and amounts due from the Manager are classified as assets in the Consolidated Statement of Assets and Liabilities.

Performance Participation Allocation— Under the Fourth Amended and Restated Limited Liability Company Agreement of the Company (as amended from time to time, the “LLC Agreement”), so long as the Management Agreement has not been terminated, the Company will be entitled to receive a Performance Participation Allocation equal to 12.5% of the Total Return attributable to Investor Shares, subject to a 5.0% Hurdle Amount and a High Water Mark, with a 100% Catch-Up (each as defined in the LLC Agreement) (the “Performance Participation Allocation”). The Performance Participation Allocation will be measured and paid on an annual basis and accrued monthly; see “Note 6. RELATED PARTY TRANSACTIONS”, below for further detail. Such Performance Participation Allocation is calculated based on the Company’s transactional net asset value, which is the price at which the Company sells and redeems its Shares. The Company may elect to receive the Performance Participation Allocation in cash and/or Class E Shares. If the Performance Participation Allocation is paid in Class E Shares, such shares may be redeemed at the Company’s request and will be subject to the redemption limitations of our share redemption program.

Segment Reporting— Series II operates through a single operating and reporting segment with a primary objective of generating attractive risk-adjusted returns consisting of both current income and long-term capital appreciation. The chief operating decision maker (“CODM”) is comprised of the Company’s Chief Executive Officer and Chief Investment Officer (the “Principal Committee”) which assesses the performance and makes operating decisions of the Company on a consolidated basis. The CODM has concluded that the Company operates as a single operating segment because the Company has a single investment strategy against which the CODM assesses the Company’s performance. In addition to other metrics, the CODM uses net increase (decrease) in net assets resulting from operations as a key metric to assess Series II’s performance. As the Company’s investment operations comprise a single reporting segment, the segment assets are the same assets that are reported in the Consolidated Statement of Assets and Liabilities and significant segment expenses are the same as those listed in the Consolidated Statements of Operations.