Hong Kong Private Equity Co-Investment for US LPs: Tax Structuring Through Offshore Feeder Funds

The second half of 2025 has brought a sharpened focus on the tax treatment of offshore private equity structures for US persons, driven by the IRS’s continued enforcement of the Foreign Account Tax Compliance Act (FATCA) and the finalisation of regulations under Section 1446(f) governing the transfer of interests in partnerships holding US real property. For US limited partners (LPs) co-investing in Hong Kong-based private equity funds, the traditional structure—a Cayman Islands or BVI feeder fund flowing into a Hong Kong operating partnership—now carries heightened federal income tax risks, including the potential for unrelated business taxable income (UBTI) from leveraged real estate investments and the application of the Section 751(a) “hot asset” rules upon disposition of the partnership interest. The 2024 OECD peer review of Hong Kong’s economic substance requirements has also prompted fund managers to re-examine whether their offshore feeder vehicles meet the “substance” thresholds necessary to avoid being re-characterised as a Hong Kong permanent establishment for treaty purposes. This article examines the core tax issues for a US LP co-investing through an offshore feeder into a Hong Kong private equity fund, focusing on the interplay between Subchapter K of the Internal Revenue Code, the US-Hong Kong Tax Information Exchange Agreement (TIEA), and the practical constraints of the Hong Kong Inland Revenue Ordinance (Cap. 112).

The Core Structural Challenge: Offshore Feeder, Hong Kong Operating Partnership

The foundational structure for a US LP co-investing in a Hong Kong private equity fund involves a two-tier vehicle: a Cayman Islands or BVI exempted limited partnership (the “Offshore Feeder”) that aggregates capital from US and non-US investors, which in turn invests as a limited partner in a Hong Kong-registered limited partnership (the “Hong Kong Operating Partnership”). The Hong Kong Operating Partnership is typically the entity that makes direct investments in portfolio companies across Asia.

The operative tax position for the US LP is that the Offshore Feeder is treated as a partnership for US federal tax purposes under the “check-the-box” default rules (Treas. Reg. § 301.7701-3(b)(1)). This means the US LP is directly allocated its share of the Hong Kong Operating Partnership’s items of income, gain, loss, and deduction, as well as any liabilities. The critical consequence is that the US LP is subject to US tax on its allocable share of the Hong Kong Operating Partnership’s income, regardless of distributions. This is a fundamental departure from the Hong Kong territorial source rule, where only income “arising in or derived from Hong Kong” is subject to Hong Kong profits tax (Inland Revenue Ordinance (Cap. 112), s. 14). The US LP must file a US tax return reporting this income, even if the Offshore Feeder has not distributed any cash.

The ECI and UBTI Trap for US LPs

A US LP that is a non-US person (e.g., a US citizen living in Hong Kong) is generally subject to US federal income tax only on its US-source income that is “effectively connected” with a US trade or business (ECI) (IRC § 871(b) for individuals; IRC § 882 for corporations). However, if the Hong Kong Operating Partnership invests in US real estate, or in a US operating company that is treated as a “trade or business” under US tax principles, the US LP’s allocable share of that income may be treated as ECI.

The more common trap for tax-exempt US LPs (e.g., US pension funds or endowments that are tax-exempt under IRC § 501(a)) is the generation of unrelated business taxable income (UBTI). If the Hong Kong Operating Partnership uses debt financing to acquire its portfolio assets, the US LP’s share of the partnership’s debt-financed income is treated as UBTI under IRC § 514. This is particularly acute for leveraged buyout funds. The UBTI threshold for a tax-exempt entity is USD 1,000 per year (IRC § 512(b)(12)). Once this threshold is exceeded, the tax-exempt LP must file Form 990-T and pay tax at trust rates on the excess. The 2024 IRS data book shows that UBTI examinations increased by 18% year-over-year, signalling increased scrutiny.

The Section 751(a) “Hot Asset” Problem on Exit

When the US LP sells or redeems its interest in the Offshore Feeder, the character of the gain is determined under IRC § 741 (generally capital gain) unless Section 751(a) applies. Section 751(a) recharacterises gain attributable to “unrealized receivables” and “substantially appreciated inventory items” as ordinary income. For a private equity fund, “unrealized receivables” includes the potential recapture of depreciation on real estate assets and, critically, the fund’s share of any “excess” of the fair market value of accounts receivable over their tax basis. The Hong Kong Operating Partnership’s holding of portfolio company debt instruments that are not capital assets can also trigger Section 751(a).

The practical consequence is that a US LP exiting a successful co-investment may find that a significant portion of its gain—potentially 20% or more of the total—is recharacterised as ordinary income, taxed at the top marginal rate of 37% (for individuals in 2025) plus the 3.8% net investment income tax (NIIT), rather than the 20% long-term capital gains rate. This is a structural inefficiency that cannot be avoided by simply holding the interest for more than one year.

Hong Kong Tax Considerations for the Operating Partnership

While the US LP’s primary tax liability is to the IRS, the Hong Kong Operating Partnership must navigate the Hong Kong profits tax regime. The Hong Kong Inland Revenue Ordinance (Cap. 112) imposes profits tax only on profits “arising in or derived from Hong Kong” from a trade, profession, or business carried on in Hong Kong (s. 14). For a private equity fund, the key question is whether the fund’s investment management and deal-sourcing activities are carried on in Hong Kong.

The “Source” Principle and the Offshore Feeder

The Hong Kong Operating Partnership is a Hong Kong resident entity for Hong Kong tax purposes (Inland Revenue Ordinance (Cap. 112), s. 2). Its profits are subject to Hong Kong profits tax at the rate of 16.5% (for corporations) or the progressive rates for unincorporated businesses (s. 14(1)). However, the fund may seek to claim that its investment income is sourced outside Hong Kong—for example, if the portfolio companies are located in Mainland China or Southeast Asia and the investment decisions are made by a management company based outside Hong Kong.

The Inland Revenue Department (IRD) has historically applied a “totality of facts” test to determine the source of profits (see CIR v. Hang Seng Bank [1991] 1 AC 306). The IRD’s 2023 Departmental Interpretation and Practice Notes (DIPN) No. 21 (revised) on “Offshore Claims” emphasises that the IRD will scrutinise the location of the decision-making, the execution of trades, and the location of the fund’s key employees. If the fund’s investment committee meets in Hong Kong and the portfolio managers are based in Hong Kong, the IRD will likely treat the profits as Hong Kong-sourced, regardless of where the portfolio companies are located.

Economic Substance Requirements for the Offshore Feeder

The Offshore Feeder (Cayman or BVI) must meet the economic substance requirements under the relevant jurisdiction’s legislation (e.g., Cayman Islands Economic Substance Law, 2018; BVI Economic Substance (Companies and Limited Partnerships) Act, 2018). For a “pure equity holding entity,” the substance requirements are minimal: the entity must comply with all statutory filing and record-keeping obligations. However, if the Offshore Feeder performs any management or advisory functions beyond passive holding, it will be classified as a “relevant entity” and must demonstrate “core income-generating activities” (CIGA) in the jurisdiction, including having a physical office, employees, and board meetings in the jurisdiction. Failure to meet these requirements can result in penalties and the automatic exchange of information with the Hong Kong tax authorities under the Multilateral Convention on Mutual Administrative Assistance in Tax Matters (MAC).

The US-HK TIEA and Information Reporting

The US-Hong Kong Tax Information Exchange Agreement (TIEA), signed in 2014 and effective in 2016, allows the IRS to request information on US LPs holding interests in Hong Kong entities. The Hong Kong Inland Revenue Department (IRD) is authorised to obtain and exchange this information under the Inland Revenue Ordinance (Cap. 112), s. 49(1A). For the US LP, this means that the Offshore Feeder’s ownership information—including the LP’s name, address, and interest—is potentially discoverable by the IRS. The 2024 IRS examination cycle saw a 22% increase in TIEA-based information requests to Hong Kong, according to the IRS’s 2024 Annual Report to Congress.

Structuring Alternatives and Mitigation Strategies

Given the tax risks outlined above, a US LP co-investing in a Hong Kong private equity fund has several structuring alternatives to consider. Each carries trade-offs in terms of complexity, cost, and IRS scrutiny.

The “Blocker” Corporation in a Low-Tax Jurisdiction

The most common mitigation strategy is to insert a “blocker” corporation—typically a Cayman Islands or BVI company—between the US LP and the Offshore Feeder. The blocker corporation is treated as a corporation for US federal tax purposes (Treas. Reg. § 301.7701-3(b)(2)). The US LP holds shares in the blocker corporation, not a direct partnership interest. This structure eliminates the US LP’s direct exposure to ECI, UBTI, and Section 751(a) “hot asset” issues, because the blocker corporation is the taxpayer on the partnership income.

However, the blocker corporation introduces a double-tax layer. The blocker corporation pays Cayman or BVI corporate income tax (typically 0%, but subject to economic substance requirements). When the blocker corporation distributes dividends to the US LP, the US LP is taxed on the dividend at the qualified dividend rate (20% for individuals in 2025) plus the 3.8% NIIT. The blocker corporation’s gain on the sale of its partnership interest is subject to US corporate tax (21% for C-corporations in 2025), and the subsequent distribution to the US LP is again taxed. The total effective tax rate on a gain can approach 40% or more.

The US LP as a Direct Investor in the Hong Kong Operating Partnership

For a US LP that is a US person (e.g., a US citizen living in Hong Kong) and who is comfortable with the direct reporting obligations, the simplest structure is to invest directly in the Hong Kong Operating Partnership without an Offshore Feeder. This eliminates the Offshore Feeder’s administrative costs and the potential for double taxation on exit. The US LP must file Form 1065 (US Return of Partnership Income) with the partnership, and Form 8865 (Return of U.S. Persons With Respect to Certain Foreign Partnerships) if the LP’s interest exceeds 10% or the value of the contribution exceeds USD 100,000.

The direct structure also exposes the US LP to the Hong Kong profits tax on its share of the Hong Kong Operating Partnership’s Hong Kong-sourced profits. However, the US LP may be able to claim a foreign tax credit (FTC) under IRC § 901 for the Hong Kong profits tax paid, subject to the FTC limitation rules (IRC § 904). The FTC is generally limited to the US tax attributable to the foreign-source income. Given that the US top rate (37% + 3.8% NIIT = 40.8%) exceeds the Hong Kong corporate rate (16.5%), the FTC will typically fully offset the US tax on the Hong Kong-sourced income, but only if the income is classified as “passive” or “general” category income under the FTC basket rules.

The US LP as a Partner in a US-Based Feeder Fund

An alternative is for the US LP to invest in a US-based feeder fund (e.g., a Delaware limited partnership) that itself invests in the Offshore Feeder. This structure is common for institutional investors. The US-based feeder fund is treated as a partnership for US tax purposes, and the US LP is allocated its share of the feeder fund’s items. The feeder fund files a single Form 1065, simplifying the US LP’s reporting. The feeder fund must also file Form 8865 if it holds a 10% or greater interest in the Offshore Feeder. This structure does not eliminate the ECI, UBTI, or Section 751(a) issues, but it centralises the compliance burden with the feeder fund’s tax preparer.

Actionable Takeaways

1. A US LP co-investing through a Cayman/BVI feeder into a Hong Kong operating partnership is directly subject to US tax on its allocable share of the partnership’s income, regardless of distributions, and must file Form 1065 and potentially Form 8865.
2. The Section 751(a) “hot asset” rules can recharacterise a significant portion of the gain on exit as ordinary income, taxed at up to 40.8%, even for a long-term hold—this must be modelled into the fund’s projected returns.
3. A blocker corporation eliminates ECI and UBTI exposure but introduces a double-tax layer that can push the effective tax rate on exit above 40%—this structure is only viable for large institutional investors with a long-term horizon.
4. The Hong Kong Operating Partnership’s profits are subject to Hong Kong profits tax at 16.5% if the investment management activities are carried on in Hong Kong, and the IRD’s 2023 DIPN No. 21 makes it increasingly difficult to claim an offshore source for profits from a Hong Kong-based fund.
5. The US-HK TIEA gives the IRS the legal authority to request the US LP’s ownership information from the IRD, and the 2024 IRS data shows a 22% increase in such requests—non-compliance with FATCA and FBAR (FinCEN Form 114) reporting carries severe penalties.

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This does not constitute tax advice. Consult a licensed CPA or tax advisor for your specific situation.