Is there a penalty under the Streamlined Foreign Offshore Procedures?

No. Under the foreign procedures, a compliant filer is not subject to failure-to-file, failure-to-pay, accuracy-related, information return or FBAR penalties. Tax and statutory interest on the three return years must be paid. The miscellaneous offshore penalty applies only under the Streamlined Domestic Offshore Procedures, which are for taxpayers who do not meet the non-residency test. Penalties already assessed for those years are not abated.

Does UK tax paid on carried interest remove my US tax on it?

Often only partly. The US foreign tax credit can offset US tax with UK tax paid on the same income, but the two countries may tax carry in different years and categories. The US can tax an allocation before cash is received, while the UK taxes receipts, and from 6 April 2026 the UK taxes carried interest as trading income. Year-by-year matching is needed to see what US tax, if any, remains.

What is the section 1061 three-year rule for carried interest?

Section 1061 applies to partnership interests held in connection with substantial services in an investment business. For these interests, gain qualifies as long-term capital gain only where the holding period exceeds three years instead of one, and gain failing that test is recharacterised as short-term capital gain. A capital interest reflecting capital actually contributed is excluded. Fund statements need holding-period data so the return can apply the rule correctly.

Do I need to report my UK LLP interest and co-investments to the IRS?

Usually yes. The IRS confirms that foreign partnership interests and foreign private equity funds are reportable on Form 8938 where the thresholds are met. Co-investments held through non-US companies may require Form 8621 as passive foreign investment companies, and foreign partnership interests can require Form 8865 depending on the filer category. Each vehicle's US classification must be established before deciding which forms apply.

How long can the IRS assess tax if I never filed Form 8938 or Form 8865?

Under section 6501(c)(8), where required information under the relevant foreign reporting sections is not furnished, the assessment period for that year does not end until three years after the IRS receives the information. If the failure was due to reasonable cause and not wilful neglect, the extension is limited to the related items. Older unfiled years can therefore remain open beyond the three-year streamlined return window.

Missed US Tax Returns: US PE Partners in London Guide

Q: Can a US private equity partner in London use the Streamlined Foreign Offshore Procedures?

Yes, if the failure to file was non-wilful and the residency test is met. A US citizen qualifies on residency where, in any one of the three most recent years with a passed due date, they had no US abode and were physically outside the United States for at least 330 full days. The submission covers three years of returns and six years of FBARs, and a compliant filer faces no penalties, only tax and interest.

Missed US tax returns are a common problem for US citizen partners at London private equity houses, and they can almost always be fixed: most partners whose failure was non-wilful can catch up through the IRS Streamlined Foreign Offshore Procedures, filing three years of returns and six years of FBARs with no penalty. The harder part is not the route but the reconstruction, because a partner's US return has to translate UK LLP profit allocations, carried interest statements and co-investment holdings into US concepts that the UK paperwork never produces.

This guide is written for the US citizen partner or principal who has lived in London for years, is usually a member of a UK limited liability partnership, and has several US filing years outstanding. In the returns we prepare for this group, the tax due is often modest once UK tax is credited. The exposure sits in the information returns, the carried interest timing mismatch and the statute of limitations, which stays open far longer than most partners assume.

Why do US private equity partners in London end up with missed US tax returns?

A US citizen is taxed on worldwide income wherever they live, and that obligation does not stop because the UK is also taxing the same income. Private equity partners fall behind for reasons we see repeatedly. Many arrived in London on secondment, assumed the firm's payroll or a UK self-assessment agent dealt with everything, and only discovered the gap when a bank asked for a US tax identification number or a fund administrator requested a US tax status certification.

Others filed a basic Form 1040 for a while, then stopped when their profit share became complex. A typical London partner's income is spread across a UK LLP profit allocation, carried interest from one or more fund vehicles, returns from co-investment programmes, and interest on cash held in UK accounts. Each item lands in a different US category, and each can trigger a separate information return. When nobody has assembled that picture, years go by unfiled.

Belief that UK tax paid removes any US filing need, when in fact the US credit system only works if a return is filed.
Profit share received as drawings during the year, with the final allocation settled months after the US filing deadline.
Carried interest that is taxable in the US before cash is distributed, so no one thought there was anything to report.
Co-investments held through non-US feeder companies that the partner never recognised as foreign corporations for US purposes.
Signature authority or interests in UK capital and drawings accounts that were never reported on an FBAR.

What are the routes to catch up on missed US tax returns?

There are three broad ways back into compliance, and the choice depends on whether the failure was wilful and whether the IRS has already made contact.

The Streamlined Foreign Offshore Procedures are the IRS programme for US taxpayers living abroad whose failures resulted from non-wilful conduct. The IRS describes non-wilful conduct as conduct due to negligence, inadvertence or mistake, or a good-faith misunderstanding of the law. A US citizen qualifies on residency if, in any one of the three most recent years with a passed due date, they had no US abode and were physically outside the United States for at least 330 full days. Both spouses must meet the test for a joint submission. The rules are set out at https://www.irs.gov/individuals/international-taxpayers/us-taxpayers-residing-outside-the-united-states.

Under the foreign procedures, a compliant filer is not subject to failure-to-file, failure-to-pay, accuracy-related, information return or FBAR penalties. Tax and statutory interest are still payable. The Streamlined Domestic Offshore Procedures, by contrast, are for people who do not meet the non-residency test and carry a miscellaneous offshore penalty; that penalty does not apply to the foreign version. For a partner who has lived in London throughout the missed years, the foreign procedures are normally the relevant ones.

Ordinary late filing is the second route. A partner can simply file the overdue returns and forms outside any programme. This can be sensible where the partner owes no US tax, has no foreign information returns outstanding and has filed every FBAR, but that is rarely the profile of a private equity partner. Without the streamlined certification, information return penalties remain available to the IRS on their normal terms.

The IRS Criminal Investigation voluntary disclosure practice is the third route. It exists for taxpayers whose conduct was wilful and who want to resolve potential criminal exposure. It involves a longer disclosure period and significant civil penalties. We describe it here only so the distinction is clear; whether conduct was wilful is a fact question that has to be examined honestly before any streamlined certification is signed.

What does a Streamlined Foreign Offshore submission contain?

The IRS asks for a specific package. In the submissions we prepare for London partners, the core components are consistent:

Delinquent or amended US income tax returns for each of the three most recent years with a passed due date, together with all required information returns for those years.
Delinquent FBARs (FinCEN Form 114) for the six most recent years with a passed due date, filed electronically through FinCEN's BSA E-Filing System, selecting Other as the late-filing reason and entering Streamlined Filing Compliance Procedures in the explanation.
A signed Form 14653 certification covering eligibility, FBAR filing and the narrative explaining why the conduct was non-wilful.
Payment of all tax due plus statutory interest for the three return years.
Each paper return and information return marked Streamlined Foreign Offshore at the top of the first page and mailed to the address the IRS lists, as electronic submissions are not accepted.

Two points matter for private equity partners. First, the information returns are attached to the paper returns in the package, even where they would normally be filed separately. Second, returns filed through the procedures can still be selected for audit. The penalty protection survives an audit unless the IRS finds that tax non-compliance was fraudulent or an FBAR violation was wilful, so the quality of the reconstruction matters as much as the route.

How do you reconstruct K-1 information from a UK LLP profit allocation?

A US partner in a US partnership receives a Schedule K-1 that breaks income into ordinary income, capital gain, interest, dividends and foreign taxes. A member of a UK LLP receives nothing of the kind. The firm produces UK partnership return figures and a partner's profit statement built for HMRC, not the IRS. Reconstructing a US-equivalent picture is the single largest task in a London partner's catch-up file.

The first question is classification. A UK LLP is a separate entity, and how it is treated for US purposes depends on the US entity classification rules and on whether a classification election was ever made for it. Many fund management LLPs have addressed this for their US members, but the partner needs to confirm the position rather than assume it, because the answer determines whether the profit share is reported as partnership income or something else entirely.

Where partnership treatment applies, the reconstruction normally works through these steps in the files we prepare:

Start from the UK partner profit statement for each UK accounting period and map it onto the US calendar tax year, since the UK tax year runs 6 April to 5 April and LLP accounting periods often differ again.
Separate the fixed or priority profit share from the discretionary allocation, and identify any amounts that are really investment returns rather than service income.
Adjust UK taxable profit to US principles, removing UK-only adjustments and identifying expenses the US treats differently.
Split out interest earned on capital accounts and any gains passed through from investments held at LLP level.
Record UK income tax and Class 4 National Insurance paid on the profit share by year, as the basis for the foreign tax credit calculation.
Keep a reconciliation that ties every US figure back to a UK document, because that reconciliation is what defends the return if it is examined.

The reconstruction is also where we find the information returns. If the LLP is treated as a foreign partnership, Form 8865 may be required in specific circumstances, and the partner's LLP interest is likely to be a specified foreign financial asset for Form 8938.

How is carried interest taxed for a US partner living in the UK?

Carried interest is a share of fund profits paid to the managers once investors have received their capital and preferred return. For a US citizen in London it is taxed by both countries, and the two systems measure it differently.

On the US side, section 1061 of the Internal Revenue Code applies to an applicable partnership interest, meaning an interest held in connection with substantial services in a business of raising or returning capital and investing in specified assets such as securities. For these interests, long-term capital gain treatment requires a holding period of more than three years rather than the usual one year, and gain that fails the three-year test is recharacterised as short-term capital gain. The statute, which applies to tax years beginning after 31 December 2017, is at https://www.law.cornell.edu/uscode/text/26/1061. A capital interest that reflects capital the partner actually contributed is excluded from the rule.

In practice this means the fund-level carried interest statement has to show the holding period of the underlying assets that produced each gain. Many non-US funds do not provide a section 1061 analysis as standard, so part of our reconstruction work is requesting holding-period data from fund finance teams or deriving it from deal dates in the investor reports.

Timing is the second US issue. Depending on the fund documents, a US partner can be allocated carried interest income for US purposes before any cash is distributed, because US partnership allocations follow the partnership agreement rather than the cash waterfall. A partner who never received a distribution may still have US income to report for a missed year.

What changed in the UK carried interest regime from April 2026?

The UK moved carried interest out of capital gains tax and into income tax. GOV.UK confirms that income tax and National Insurance contributions are payable on carried interest received from 6 April 2026, at https://www.gov.uk/capital-gains-tax/rates. Under the revised regime published at https://www.gov.uk/government/publications/reform-of-the-tax-treatment-of-carried-interest/revised-tax-regime-for-carried-interest, the individual is treated as carrying on a trade, carried interest less permitted deductions is treated as trading profits subject to income tax and Class 4 National Insurance, and where carried interest is qualifying, 72.5 percent of the qualifying profits is treated as trading profits. Whether carried interest is qualifying depends on the average holding period of the investment scheme under the legislation.

The regime applies to UK tax residents and to carried interest relating to investment management services performed in the UK. For a missed-returns file covering earlier years, the pre-April 2026 UK treatment will still govern those years, so the US credit calculation must use the UK tax actually charged for each year rather than the new rules.

How does the foreign tax credit work against UK tax on carry?

The foreign tax credit lets a US citizen reduce US tax by UK tax paid on the same income, which is why many London partners owe little or no US tax once returns are prepared. It is not automatic, and private equity income creates three recurring problems.

Timing mismatches: the US may tax carry when it is allocated while the UK taxes it on receipt, so UK tax can arrive in a later year than the US income. Carryback and carryforward rules exist for excess credits, but they are time limited, and missed years can push credits out of reach if returns are not filed promptly.
Character and category: the credit is calculated within separate limitation categories, so UK tax on income the US treats as passive investment income cannot always shelter US tax on service income, and the reverse. The 2026 UK shift to trading-income treatment for carry does not change how the US characterises the same amounts.
Rate differences: where the US treats carry as long-term capital gain at preferential rates while the UK charges a higher rate, excess UK tax builds up as credits that may never be used. Where section 1061 recharacterises gain as short-term, the US rate rises and more UK tax becomes usable.

In the returns we prepare, we build a year-by-year matching schedule that pairs each US income item with the UK tax charged on it. This is the document that most often turns a frightening estimate into a modest liability, and it is also where errors are most expensive.

Which information returns apply to co-investments and non-US fund vehicles?

Co-investment programmes are where London partners accumulate the most unreported information returns. Firms typically offer co-investment alongside the main fund, often through a non-US partnership, a Luxembourg or Jersey vehicle, or a feeder company. The form required depends on how each vehicle is classified for US purposes.

Form 8621 for a passive foreign investment company: a non-US corporation whose income or assets are mainly passive is generally a PFIC, and many fund feeder and blocker companies fall into this category for a US investor. PFIC rules can impose punitive tax and interest charges on distributions and gains unless an election such as a qualified electing fund election was made in time.
Form 8865 for a foreign partnership: required for US persons in specific categories, including control of more than 50 percent, a 10 percent or greater interest where the partnership is controlled by US persons, certain contributions of property exceeding $100,000 in a 12-month period combined with prior contributions, or reportable acquisitions and dispositions. The categories are set out in the IRS instructions at https://www.irs.gov/instructions/i8865.
Form 5471 for a foreign corporation: relevant where a partner holds or acquires a qualifying interest in a non-US corporation, such as a personal holding company or a management vehicle. A filer who meets both Category 4 and Category 5a checks only Category 4.
Form 8938 for specified foreign financial assets: the IRS confirms that foreign partnership interests, foreign hedge funds and foreign private equity funds are reportable on Form 8938.

The Form 8865 penalty for Categories 1 and 2 is $10,000 per tax year for each foreign partnership, with further amounts after an IRS notice and a reduction in available foreign tax credits. This is exactly the type of penalty the Streamlined Foreign Offshore Procedures remove for a non-wilful filer, which is why getting each vehicle into the submission matters.

Do FBAR and Form 8938 cover capital and drawings accounts?

Yes, frequently. The FBAR is required when the aggregate value of a US person's foreign financial accounts exceeds $10,000 at any time during the calendar year. It is filed with FinCEN, not with the tax return, and signature authority over an account counts subject to exceptions. Personal UK current accounts, savings accounts, brokerage accounts and any account into which drawings are paid all count toward the aggregate.

Form 8938 is filed with the tax return and has higher thresholds for taxpayers living abroad. According to the IRS comparison at https://www.irs.gov/businesses/comparison-of-form-8938-and-fbar-requirements, an unmarried taxpayer living abroad files where specified foreign financial assets exceed $200,000 on the last day of the year or $300,000 at any time, and married couples filing jointly where they exceed $400,000 at year end or $600,000 at any time. For a London partner, the LLP interest, fund interests and co-investment holdings can count toward Form 8938 even though they do not appear on the FBAR, and the FBAR can capture accounts that Form 8938 does not.

A capital account in the LLP is a partner's equity, not a bank account, so it does not by itself go on the FBAR. Cash accounts held in the partner's name, joint accounts, and any firm account over which the partner has signature authority need individual review.

Does the statute of limitations stay open while information returns are missing?

This is the gap angle most London partners never hear about. Under section 6501(c)(8), where information required under sections including 6038, 6038B, 6038D, 6046 and 6046A, or a PFIC-related election under section 1295(b) or 1298(f), is not furnished, the time to assess any tax for that year does not expire until three years after the IRS receives the information. The text is at https://www.law.cornell.edu/uscode/text/26/6501. If the failure is due to reasonable cause and not wilful neglect, the extension applies only to the items related to the failure.

Those sections are the statutory sources behind Forms 5471, 8865 and 8938. In plain terms, a partner who never filed Form 8938 or a required Form 8865 for an older year may face a tax year that remains open, potentially for all items, long after the normal three-year window. The streamlined procedures ask for three years of returns, but the earlier years do not automatically close. In our files we review the years before the streamlined window for unfiled information returns and record the reasonable-cause position, so the partner understands exactly which years remain exposed.

Worked scenario: a London partner with five unfiled US years

The following figures are an illustration only. An exchange rate of $1.30 to £1 is assumed throughout and is not a rate for any specific year.

A US citizen has lived in London since 2017, is a member of a UK LLP that manages a non-US buyout fund, and last filed a US return for 2020. In each recent year their UK profit share was about £600,000 (about $780,000 at the assumed rate), on which UK income tax and Class 4 National Insurance were paid. They also hold a carried interest in the fund through a non-US partnership, which allocated a US-basis gain of about £400,000 (about $520,000) in one year before any distribution, and co-investments through a non-US feeder company. They hold three UK bank accounts and have signature authority over a small firm account.

They were outside the US for more than 330 full days in each recent year and had no US abode, and their failure arose from a mistaken belief that UK tax ended their US obligations. On those facts, the Streamlined Foreign Offshore Procedures are the expected route. The package would contain three years of Form 1040 with Forms 1116, 8938, 8621 for the feeder company, and Form 8865 if their fund interest crossed a filer category, plus six years of FBARs and Form 14653.

On the profit share, UK tax paid at UK marginal rates is likely to cover the US liability on that income through the foreign tax credit. The pressure point is the carry: the US-basis allocation arises before the UK taxes anything, and the fund's holding-period data determines whether section 1061 treats the gain as long-term or short-term. If UK tax on that carry lands in a later year, the credit must be matched across years, and some US tax and interest may be payable for the allocation year. The feeder company may also generate a PFIC charge that no UK payment offsets. In this illustration the bulk of the cost is professional reconstruction and a targeted tax-and-interest payment on carry and PFIC items, not penalties.

The final step is the earlier years. Because 2018 and 2019 sit outside the three-year return window but were never covered by Forms 8938 or 8621, the file includes a section 6501(c)(8) review so the partner knows whether those years remain open.

What should a London PE partner gather before filing?

In our experience the speed of a catch-up depends almost entirely on documents. The items we request from private equity partners first are UK self-assessment returns and HMRC statements for each year, LLP partner profit statements and capital account statements, carried interest and fund investor statements with deal dates, co-investment subscription documents identifying each vehicle, year-end and peak balances for every UK account, and a travel record supporting the 330-day test. With those in hand, the reconstruction becomes an accounting exercise rather than an investigation.