Do I need to file Form 5471 if my UK company made a loss?

Yes. Form 5471 filing depends on ownership and control, not profit. A US citizen or green card holder who controls more than 50% of a UK company, or owns 10% or more of a UK company that is a controlled foreign corporation, files the form every year. The IRS instructions say a required schedule must be filed even when all amounts are zero, and a loss-making company has negative figures that must be reported.

What happens to Form 5471 when a Series A takes me below 50%?

Control is tested at any time during your tax year, so if you held more than 50% before the round closed you remain a Category 4 filer for that year. In later years, the question is whether US shareholders together still own more than 50%. If they do, the company stays a CFC and you file as a Category 5a filer. If not, you may fall outside Categories 4 and 5 entirely.

Does a tested loss mean I can skip Form 8992?

No. Schedule I-1 of Form 5471 reports the tested loss at company level, and Form 8992 with Schedule A is where a US shareholder computes their own position. If the loss-making UK start-up is your only CFC, the result is usually no inclusion, but the computation still has to be completed. For years beginning after 31 December 2025, the regime is renamed net CFC tested income under Public Law 119-21.

Do my UK corporation tax losses carried forward reduce US earnings and profits?

Not in the same way. In the UK, HMRC lets a company carry trading losses forward against future profits, subject to the restriction for larger amounts. In the US computation, each year's deficit is booked to accumulated earnings and profits on Schedule J in the year it arises. When the company becomes profitable, UK loss relief lowers the UK tax bill, but the old losses are not deducted again in the US current-year figures.

Does an R&D tax credit from HMRC affect my Form 5471?

It can. A payable credit under the merged R&D expenditure credit scheme or enhanced R&D intensive support is cash received by the company, and its accounting treatment flows into Schedule C and the Schedule H adjustments. A refundable credit is also different from UK corporation tax paid, which matters for the foreign tax side of the US computation once the company becomes profitable. Keep the R&D claim papers with your US workpapers.

What is the penalty for not filing Form 5471 for a UK start-up?

The December 2025 instructions set a $10,000 penalty for each annual accounting period of each foreign corporation, plus a further $10,000 for each 30-day period the failure continues more than 90 days after an IRS notice, capped at $50,000. Foreign tax credits can also be reduced. These penalties apply even when no US tax was due, which is why loss-making companies are a frequent source of unexpected exposure.

Form 5471 for a Loss-Making UK Start-Up: Founder Guide

Form 5471 is required for a US founder of a loss-making UK limited company even when the company has never made a penny of profit, because the filing obligation is triggered by ownership and control, not by income. If you are a US citizen or green card holder and you control more than 50% of your UK start-up, or you own 10% or more of a UK company that is a controlled foreign corporation, the IRS expects a full Form 5471 with your Form 1040 every year, losses and all. The penalty for missing it starts at $10,000 per company per year, whether or not any US tax was due.

In the returns we prepare for American founders, the most common misconception is "no profit, no filing". But Form 5471 is an information return, and a loss-making company still has an income statement, a balance sheet, an earnings and profits deficit, shareholder transactions and an ownership history to report. This guide covers your filer category, how losses appear on the schedules, how a tested loss is treated, what a funding round changes, and the failure modes we see most often.

Why is Form 5471 required when the UK company makes a loss?

Form 5471 is the Information Return of US Persons With Respect to Certain Foreign Corporations. The current instructions, revised December 2025 and published at https://www.irs.gov/instructions/i5471, define five categories of filer. None of the categories that matter to a founder contain a profit test. They turn on who you are, how much you own and whether the company is a controlled foreign corporation (CFC).

The instructions are explicit that zero is not a reason to omit anything: when a schedule is required but all amounts are zero, the schedule should still be filed with one or more zero amounts. A loss-making company is not even a zero case. It has real numbers, they are simply negative, and negative numbers have to be reported in the right places for the US shareholder computation to work.

A summary procedure for dormant foreign corporations under Rev. Proc. 92-70 allows only page 1 to be completed, but a start-up that employs staff, pays suppliers and raises equity is not dormant in any ordinary sense. Check the definition in section 3 of that revenue procedure before relying on it.

Which Form 5471 categories apply to a US founder?

Most US founders of a UK start-up fall into Category 4, Category 5a, or both, with Categories 2 and 3 appearing around funding rounds. The definitions below are taken from the December 2025 instructions.

Category 4: a US person who had control of the foreign corporation during its annual accounting period. Control means owning more than 50% of the total combined voting power of all classes of voting stock, or more than 50% of the total value of all classes of stock, at any time during the US person's tax year.
Category 5: a US shareholder who owned stock in a CFC at any time during the year and who owned that stock on the last day the company was a CFC. A US shareholder for this purpose owns, directly, indirectly or constructively, 10% or more of the voting power or value. Category 5a is the standard case, meaning a Category 5 filer who is not a 5b or 5c filer.
Category 3: broadly, a US person who acquires stock that takes them to 10% or more, who becomes a US person while holding 10% or more, or who disposes of enough stock to fall below 10%. This is the event-driven category tied to Schedule O.
Category 2: a US citizen or resident who is an officer or director of a foreign corporation in which a US person has acquired 10% or more, or an additional 10% or more. A US founder sitting on the board when a US venture fund invests can be pulled in here.

A CFC, under the same instructions, is a foreign corporation whose US shareholders together own more than 50% of the voting power or value on any day of the corporation's tax year. A US founder holding 60% of a UK limited company makes that company a CFC on their own.

Where you meet both Category 4 and Category 5a, the instructions say to check only the Category 4 box and leave Category 5a blank. Checking only 5a understates your obligations, including Schedule M.

How do losses appear on Schedule C, Schedule H and Schedule J?

Three schedules carry the loss through the form, and the hand-offs between them are where most of the work sits.

Schedule C is the income statement. The instructions require it in the foreign corporation's functional currency in accordance with US GAAP. A UK start-up typically keeps its books under FRS 102 or FRS 105, so the statutory accounts loss filed at Companies House is a starting point, not the finished Schedule C figure.

Schedule H reports current-year earnings and profits (E&P) for US tax purposes. It starts from net book income or loss on line 1, then makes the adjustments required by Regulations section 1.964-1(b) and (c) on lines 2a through 2i to conform the books to US GAAP and US tax accounting principles. Depreciation, inventories and the difference between book income tax expense and the taxes that actually reduce E&P are all called out. The result on line 5c is the current-year E&P, or the deficit in E&P, and for a loss-making start-up that figure is negative. Line 5d translates it into US dollars at the average exchange rate for the year.

Schedule J tracks accumulated E&P. Line 3 picks up the current-year E&P or deficit from Schedule H line 5c, and column (a) holds post-2017 E&P not previously taxed, the section 959(c)(3) balance. Year after year of losses builds an accumulated deficit on Schedule J, which becomes the opening position against which future profits and distributions are measured. If the first Form 5471 is prepared years late without reconstructing earlier years, that balance is wrong from day one.

Schedule F is the balance sheet, in US dollars. Schedule M reports transactions with shareholders and related persons, and every Category 4 filer must file it. Founder loans, director's salary and personally paid expenses recharged to the company are classic Schedule M items.

What is a tested loss, and how does Schedule I-1 feed Form 8992?

A tested loss is the negative result, for a CFC, of the computation used in the US global minimum tax regime under section 951A. For years covered by the December 2025 Form 5471 instructions and the Form 8992 instructions at https://www.irs.gov/instructions/i8992, that regime is still described as global intangible low-taxed income (GILTI), and Form 8992 is titled US Shareholder Calculation of Global Intangible Low-Taxed Income.

The law has since moved. IRS Notice 2025-72, at https://www.irs.gov/pub/irs-drop/n-25-72.pdf, confirms that under the amendments made by Public Law 119-21, commonly called the One Big Beautiful Bill Act, for taxable years beginning after 31 December 2025 the US shareholder includes its net CFC tested income under section 951A, determined from its pro rata share of each CFC's tested income or tested loss. In practice, a founder filing for 2025 will still see GILTI on the forms, while 2026 and later years fall under the net CFC tested income wording. Always prepare a given year on the form revision that the IRS has issued for that year, because line references and names may change.

At the CFC level, Schedule I-1 does the arithmetic. Line 4 is gross income less exclusions, line 5 is the allocable deductions including taxes, and line 6 is the result, which can be positive (tested income) or negative (tested loss). The instructions then say that if the CFC has a tested loss on line 6, enter zero on line 7 (tested foreign income taxes) and zero on line 8 (qualified business asset investment). Line 6 is translated into US dollars at the average exchange rate for the CFC's year.

At the shareholder level, an individual US shareholder who is not part of a consolidated group completes Form 8992 with Schedule A. The Form 8992 instructions direct you to enter the US dollar tested loss from line 6 of Schedule I-1 for each CFC, and then your pro rata share of it. If your only CFC is a loss-making UK start-up, the practical result is usually no inclusion for the year. But that nil result only exists once Form 8992 has been completed.

If you hold more than one CFC, for example a profitable UK consultancy and a loss-making start-up, a tested loss in one can offset tested income in the other; the Form 5471 instructions include a worked example of this offset. And these are annual computations: a tested loss enters the calculation in its own year and is not carried forward on these forms the way a UK trading loss is.

Do UK trading losses carried forward reduce US E&P the same way?

No. The UK and US systems track losses in different places.

On the UK side, the GOV.UK guidance at https://www.gov.uk/guidance/work-out-and-claim-relief-from-corporation-tax-trading-losses explains that a company can offset a trading loss against other profits of the same accounting period, carry it back against profits of the previous 12 months where the same trade was carried on, or carry it forward against future profits. For carried-forward losses arising from 1 April 2017, relief is restricted broadly to an allowance of up to £5 million plus 50% of remaining profits. Losses are reported on the CT600, and for a start-up carry forward is usually the only route that matters.

On the US side, a deficit is booked into accumulated E&P on Schedule J in the year it arises; there is no Form 5471 line for a carried-forward UK trading loss. When the company turns profitable and uses brought-forward losses to cut its UK bill, the US computation does not deduct those old losses again. Current-year E&P is positive, the accumulated deficit starts to unwind, and prior-year tested losses do not reappear. The result is a timing mismatch: the first profitable UK year may carry little UK tax, while the US computation sees positive tested income with little foreign tax attached.

The precise outcome depends on the facts, other CFCs you hold, and whether you make a section 962 election, which the instructions describe as letting a non-corporate US shareholder be taxed at corporate rates on these inclusions to claim a credit for certain foreign taxes. We model that first profitable year in advance for founders.

What happens to Form 5471 after a Series A dilutes the founder?

Funding rounds change the category, not the obligation to think about it. The two tests to rerun after every round are whether you still have control (more than 50%, Category 4) and whether the company is still a CFC (US shareholders together over 50%, Category 5). We cover the full mechanics in a separate post on a company ceasing to be a CFC, so this section is deliberately brief.

Control is tested at any time during your tax year. If you held 60% until a round closed in June, you had control that year and remain a Category 4 filer for that year, even though you end the year at 35%.
CFC status is tested on any day of the company's tax year. A company that was a CFC for the first half of the year was a CFC for that year, and a US shareholder who held stock on the last day it was a CFC is a Category 5 filer.
Who the new investors are matters. If a US venture fund structured as a domestic partnership takes 25% and you hold 35%, US shareholders own 60% together and the company stays a CFC, with you as a Category 5a filer.
If the new investors are UK or European funds and no other US shareholder holds 10% or more, the company stops being a CFC from the round, and in the following full year you may fall outside Categories 4 and 5 altogether.
Crossing the 10% line in either direction, or a US person acquiring 10% while you are a director, can trigger Category 3 or Category 2 reporting with Schedule O, even in a year when Categories 4 and 5 no longer apply.

Constructive ownership can change these answers: shares held by family members or entities you own can be attributed to you, and options can count in some circumstances. EMI options granted to UK employees rarely move the founder's percentage on their own, but a large pool exercised at exit can.

Worked scenario: a founder at 60%, then 35% after a Series A

This is an illustration with assumed figures, not a real client. Assume an exchange rate of 0.7800 pounds per US dollar for each year, which is how Form 5471 wants rates shown: the instructions require a divide-by convention, meaning units of foreign currency per one US dollar, rounded to at least four places.

Facts. Maya, a US citizen in London, incorporates a UK software company in 2024 with a 31 December year end. She owns 60% and her non-US co-founder 40%. No other US person holds shares.

Year 2025. The company records a book loss of £500,000 under FRS 102. After the Schedule H adjustments, the current-year deficit on line 5c is assumed at £480,000, about $615,385 at the assumed rate. Maya meets Categories 4 and 5a and checks only Category 4. She completes Schedule C, Schedule F, Schedule H (the £480,000 deficit), Schedule I-1 (a tested loss on line 6, zero on lines 7 and 8), Schedule J (the deficit flows to line 3) and Schedule M (her £50,000 director's loan). On Form 8992 and Schedule A she reports her share of the tested loss and has no inclusion. The company's CT600 shows a trading loss carried forward.

Year 2026. On 30 June a Series A closes with a London fund and a European fund, and Maya is diluted to 35%. She had control until 30 June, so she is still a Category 4 filer for 2026, and the company was a CFC for its 2026 year. It loses an assumed £1,200,000. Because 2026 is a year beginning after 31 December 2025, the shareholder computation falls under the net CFC tested income rules, on whatever Form 8992 revision the IRS issues for 2026. Part-year CFC pro rata rules are technical; the Form 8992 instructions refer to Regulations section 1.951A-1(d).

Year 2027. Maya holds 35% all year, no other US person owns 10% or more, so the company is not a CFC and she lacks control. Unless Category 2 or 3 is triggered, she may have no Form 5471 for 2027. But the company account she signs on brings in the FBAR, and her shares may need to go on Form 8938, because the instructions' rule that items on Form 5471 need not be repeated on Form 8938 no longer helps in a year with no Form 5471. The category answer changed three times in three years while the company never made a profit.

How do R&D tax relief receipts show up for a US founder?

Many UK start-ups claim research and development relief. GOV.UK guidance at https://www.gov.uk/guidance/research-and-development-rd-tax-relief-the-merged-scheme-and-enhanced-rd-intensive-support explains that for accounting periods beginning on or after 1 April 2024 there are two routes: the merged R&D expenditure credit scheme, and enhanced R&D intensive support for loss-making, R&D-intensive small and medium-sized enterprises, which can produce a payable tax credit.

For Form 5471, the point is classification. How the accounts record a payable credit, as other income or within the tax line, flows into Schedule C and the Schedule H adjustments, and a refundable credit is not the same as UK corporation tax paid, which matters once foreign taxes feature in the US computation.

What are the Form 5471 penalties for a missed year?

The penalties in the December 2025 instructions apply regardless of whether any US tax was due, which is exactly why loss-making companies are dangerous: founders assume no tax means no exposure.

A $10,000 penalty for each annual accounting period of each foreign corporation for failure to furnish the information required by section 6038(a) on time.
If the information is not filed within 90 days after the IRS mails a notice, an additional $10,000 for each 30-day period or part of one, capped at $50,000 per failure.
A reduction of 10% of the foreign taxes available for credit under sections 901 and 960, with further 5% reductions for each three-month period the failure continues after the 90-day period, subject to the limits in section 6038(c)(2).
A separate $10,000 penalty structure under section 6679 for failures relating to section 6046 and Schedule O, the acquisition and disposition reporting.
Criminal penalties under sections 7203, 7206 and 7207 may apply in serious cases.

The instructions add that a person who agrees to have someone else file for them remains exposed if that person does not file a correct return.

How do you catch up on missed Form 5471 filings?

The right route depends on whether income was also missed and on your reasons. The IRS page on delinquent international information returns, at https://www.irs.gov/individuals/international-taxpayers/delinquent-international-information-return-submission-procedures, describes filing late information returns with an amended return and an optional reasonable cause statement for taxpayers who are not under civil examination or criminal investigation and have not been contacted by the IRS about the returns. It is clear that penalties may still be assessed under existing procedures.

Where the missed Form 5471 sits alongside missed income or missed FBARs, the Streamlined Filing Compliance Procedures at https://www.irs.gov/individuals/international-taxpayers/streamlined-filing-compliance-procedures are often the better fit for a non-wilful founder. The Streamlined Foreign Offshore Procedures, for qualifying taxpayers resident outside the US, carry no penalty; the 5% miscellaneous offshore penalty applies only to the Streamlined Domestic Offshore Procedures. Late FBARs themselves are filed through FinCEN's BSA E-Filing System with a reason for late filing, or within the Streamlined submission. FinCEN's guidance at https://www.fincen.gov/report-foreign-bank-and-financial-accounts confirms that a US person with a financial interest in or signature authority over foreign accounts must file if their aggregate value exceeds $10,000 at any time in the calendar year, and a founder who signs on the company account usually has signature authority.

Form 5471 is attached to your income tax return and filed by its due date, including extensions. Whatever the route, rebuild Schedule H for each missed year and roll Schedule J forward from incorporation.

Form 5471 checklist for a loss-making UK start-up

Map the cap table at the start of the year, at each round and at the year end, including attributed holdings.
Decide the categories; if both 4 and 5a apply, check only Category 4.
Convert the UK accounts to US GAAP for Schedule C and document each Schedule H adjustment.
Roll forward Schedule J from incorporation so the accumulated deficit is correct.
Complete Schedule I-1 and record the tested loss on line 6, with zero on lines 7 and 8.
Complete Form 8992 and Schedule A using the revision for that year, noting the shift to net CFC tested income for years beginning after 31 December 2025.
Report founder loans, salary and recharges on Schedule M.
Use the divide-by convention for every exchange rate, rounded to at least four places.
Check FBAR and Form 8938 for the company bank account and your shares.
Keep R&D relief claims and CT600 loss computations with the US workpapers.

Failure modes we see with loss-making start-ups

The patterns repeat: not filing because the company lost money; filing page 1 only on the belief that the company is dormant; checking Category 5a alone when the founder has control, which drops Schedule M; carrying the UK statutory loss straight onto Schedule H without adjustments; forgetting Form 8992 because there is no inclusion; assuming a funding round ended all reporting when earlier control kept the founder in Category 4; and neglecting Schedule J, so the accumulated deficit is unreliable when the company is profitable, pays a dividend or is sold. An annual review tied to the cap table and UK accounts avoids all of them.

Our team prepares Form 5471, Form 8992, FBAR and related US returns for founders and investors, including catch-up filings for missed years. Contact us at us-uktax.com to review your position before the next deadline.