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

Yes. The filing duty depends on your ownership and control of the company, not on whether it was profitable. A US citizen who controls a UK limited company files Form 5471 with their Form 1040 every year, including loss years. The penalty for not filing is $10,000 per company per year regardless of whether any US tax was due, so a loss year still needs a complete form.

Does giving my non-American spouse half the shares avoid Form 5471?

No. Splitting shares with a spouse can save UK income tax by using two sets of allowances and bands, but the US constructive ownership rules can attribute your spouse's shares to you. A company owned 50/50 by a US citizen and their non-US spouse is still normally a controlled foreign corporation, and the US citizen still files Form 5471. Only US persons in a filer category file.

Is a UK company paying 25% corporation tax exempt from net CFC tested income?

Not automatically. A company taxed at the UK 25% main rate will usually qualify for the high-tax exclusion, but the exclusion is an election you make on the US return, and the effective rate is measured on US tax principles. If you do not elect it, the profit can be included in your US income as net CFC tested income even though UK tax was high.

Is my UK dental practice LLP reported on Form 5471?

Generally not. A UK limited liability partnership or traditional partnership is usually treated as a foreign partnership for US purposes, so a US partner reports it on Form 8865 rather than Form 5471. Your share of the partnership profit flows onto your Form 1040 each year. The controlled foreign corporation rules and the high-tax election for corporations do not apply to it in the same way.

Does HMRC need to know that I file Form 5471 in the US?

No. Form 5471 is a purely US information return filed with your Form 1040, and HMRC does not require you to report it. Your UK obligations, the company's accounts, corporation tax return and your own Self Assessment for salary and dividends, are unchanged. The UK figures do, however, feed directly into Form 5471, so the two sets of filings must reconcile.

How far back do I have to go to catch up on missed Forms 5471?

Under the Streamlined Foreign Offshore Procedures you file the three most recent years of returns with their Forms 5471 and six years of FBARs, with no penalty for eligible non-willful filers. If all income was already reported, the delinquent information return procedures let you attach late forms to amended returns. Because a missing 5471 keeps the statute open, older years remain exposed until addressed.

Form 5471 for a UK Dental or Medical Practice Company

Form 5471 is the annual US information return a US citizen must file when they own and control a foreign corporation, and a UK limited company that runs your dental surgery, GP-turned-private clinic or medical consultancy is exactly that. If you hold more than half of the company, alone or once your family's shares are counted, you will normally file as a Category 4 and Category 5a filer, attach a full set of schedules to your Form 1040, and report the company's profits under the US controlled foreign corporation rules every year, whether or not you take a penny out.

In the returns we prepare for clinicians, the company itself is rarely the problem. UK accounts are filed and corporation tax is paid. The problem is that the US side was never set up: a dentist incorporates on UK advice, the structure works perfectly in Britain, and years later someone mentions that the IRS expected a Form 5471 for every one of those years.

Does a US Citizen Who Owns a UK Practice Company Have to File Form 5471?

Yes. A UK private limited company is treated as a foreign corporation for US purposes, and a US citizen who controls one has an annual reporting duty under section 6038 of the Internal Revenue Code. The duty follows citizenship, not residence, so it applies however long you have lived in Britain, whatever the size of the practice, and whether the company made a profit or a loss.

Form 5471 is not a separate tax return with its own tax bill. It is attached to your Form 1040 and is due when that return is due, including extensions. What makes it consequential is that its figures drive real US tax: the controlled foreign corporation rules use them to decide whether company profit must be included in your US income in the year it is earned. The IRS instructions at https://www.irs.gov/instructions/i5471 were revised in December 2025 to reflect the One Big Beautiful Bill Act.

Which Form 5471 Filer Category Applies to a Practice Owner?

The form sorts filers into five categories, and the category decides which schedules you complete. For a clinician who owns the company outright or with family, two categories matter most.

Category 4 is a US person who had control of the foreign corporation during its annual accounting period, meaning more than 50% of the total voting power or more than 50% of the total value of its shares. A sole or majority owner of a practice company meets this almost by definition.
Category 5 is a US shareholder of a controlled foreign corporation, and Category 5a is the ordinary version of it, a Category 5 filer that is not in the special 5b or 5c subcategories. A practice owner who controls the company is also a US shareholder of a CFC, so they meet Category 5a as well.
Where you meet both Category 4 and Category 5a, the instructions say you check only the Category 4 box and leave Category 5a blank. You still complete every schedule that either category requires; the single tick does not reduce the reporting.
Category 2 covers a US citizen who is an officer or director of a foreign corporation in which a US person has acquired a 10% stake, and Category 3 covers certain acquisitions and dispositions of 10% stock. In the year you incorporate the practice, or in a year you buy out a partner, these can apply alongside Category 4.

Is Your UK Practice Company a Controlled Foreign Corporation?

A controlled foreign corporation, or CFC, is a foreign company in which US shareholders together own more than 50% of the vote or value. A US shareholder for this purpose is a US person who owns 10% or more of the vote or value. A UK practice company owned wholly or mainly by a US citizen clinician is therefore a CFC from the day it is formed. The older rule that a corporation had to be a CFC for an uninterrupted 30 days before the inclusion rules bit was removed by the 2017 Act, so there is no grace period in the year of incorporation.

Ownership for these tests is not only what is printed on the share register. The instructions apply constructive ownership rules by reference to section 958, which borrows the family attribution rules of section 318, so shares held by your spouse, children or parents can be treated as owned by you. A common UK arrangement gives a spouse a block or separate class of shares so dividends use two sets of personal allowances and bands. If your spouse is also a US citizen, both of you may file your own Form 5471. If your spouse is not a US person, a 50/50 split does not take the company outside CFC status, because their shares can be attributed to you. The UK saving is real; the US reporting does not go away.

Which Form 5471 Schedules Will a Wholly Owned Practice Company Need?

A Category 4 filer, which is what the owner of a practice company almost always is, completes the full form. Based on the filing requirements table in the current instructions, that means the identifying information on page 1 of Form 5471 together with the following, each of which has a practical meaning for a clinical business:

Schedule A, the share capital, where a spouse share class or an associate buy-in becomes visible
Schedule B, the US and foreign shareholders, including a spouse who holds shares
Schedule C, the income statement, restating fee income, associate costs, laboratory fees, materials and staff costs in US dollars
Schedule E and Schedule E-1, the taxes paid or accrued, where UK corporation tax is recorded for the credit and high-tax analysis
Schedule F, the balance sheet, including equipment, goodwill and the director's loan account
Schedule G and Schedule G-1, a questionnaire that asks whether the company has income taxed abroad above 90% of the top US corporate rate
Schedule H, current earnings and profits under US tax principles, which rarely equals the UK profit because of equipment depreciation, goodwill and exchange differences
Schedule I and Schedule I-1, the shareholder's income from the CFC and the section 951A inclusion data
Schedule J and Schedule P, accumulated and previously taxed earnings and profits, which stop profit already taxed in the US being taxed again on distribution
Schedule M, transactions with shareholders and related persons, capturing salary, dividends, director's loan movements and any surgery rent paid to you
Schedule Q and Schedule R, CFC income by group and distributions to US shareholders

What Happened to GILTI for Tax Years Beginning After 2025?

GILTI, the global intangible low-taxed income regime introduced in 2017, has been renamed and reshaped. The 2025 law, Public Law 119-21, changed the heading of section 951A to net CFC tested income, usually shortened to NCTI. The current statute, which you can read at https://www.law.cornell.edu/uscode/text/26/951A, now requires each US shareholder to include their net CFC tested income in gross income, and the notes there confirm that the changes apply to taxable years beginning after December 31, 2025.

The change that matters most to a clinical business is the removal of the old tangible asset carve-out. Under GILTI, a deemed return on the company's qualified business asset investment, broadly the tax basis of its depreciable equipment, was taken out of the inclusion. A dental practice with chairs, imaging equipment and a substantial fit-out sometimes had a meaningful amount of profit shielded this way. The 2025 law struck out both the net deemed tangible income return and the qualified business asset investment provisions, so for tax years beginning after 2025 that shield no longer exists. Equipment-heavy practices lose the most from the change.

For an individual owner the basic mechanics remain: tested income is broadly the company's gross income after allocable deductions, excluding categories such as income covered by the high-tax exception, and your pro rata share is included on your Form 1040 at ordinary rates. Individuals do not automatically receive the deduction and deemed-paid credit available to a US corporation, which is why the section 962 election remains relevant. IRS guidance on several details was still developing when the December 2025 instructions were issued, so we model each year under its own rules.

Can the High-Tax Exclusion Shelter Practice Profits From US Tax?

Often it can, and for a UK practice company it is usually the most valuable election on the return. The high-tax exclusion lets a US shareholder elect to exclude from tested income any income taxed abroad at an effective rate greater than 90% of the maximum US corporate rate in section 11. The statute builds it into the definition of tested income by cross-referring to section 954(b)(4), and Form 5471 addresses it on Schedule G and Schedule Q.

UK corporation tax decides whether the practice qualifies. GOV.UK states at https://www.gov.uk/corporation-tax-rates that the main rate is 25%, that companies with profits of £50,000 or less pay the small profits rate of 19%, and that Marginal Relief may apply between £50,000 and £250,000, with those limits reduced for short accounting periods and associated companies. A company paying the full 25% will generally clear the US threshold with room to spare. A company at 19% sits much closer to the line, and the effective rate is computed on US tax principles, so timing differences and exchange rates can push a company that looks high-taxed in the UK below the threshold.

The effective rate is tested on US-measured income, not the UK taxable profit shown in the corporation tax computation
A year of large capital allowances on new equipment can reduce UK tax relative to US-measured income and depress the effective rate
Marginal Relief companies pay an effective rate between 19% and 25%, so the outcome depends on where in the band the profit falls
The election is made annually and generally applies consistently across the CFCs of the same controlling owner group, so it should be decided with all of your companies in view

Salary, Dividends or Retained Profits: How Does Each Land on Your US Return?

UK practice owners typically extract profit through a mix of a director's salary and dividends, and leave the rest in the company. Each route behaves differently on the US return, and the UK-optimal mix is not always the US-optimal one.

Salary is earned income for US purposes. It is reported on your Form 1040, the company deducts it in computing both UK profit and US tested income, and it can be sheltered either by the Foreign Earned Income Exclusion or by the Foreign Tax Credit for the UK income tax deducted under PAYE. A low salary is common in UK planning because dividends attract no National Insurance; for a US owner a low salary also means a smaller pool of earned income for US relief and more profit left in the company to be tested under the CFC rules.

Dividends paid out of profits that have not already been taxed in the US are taxable when received. Dividends from a UK company can qualify for the lower US rates on qualified dividends because of the US-UK income tax treaty, and the UK dividend tax you pay can support a Foreign Tax Credit. The difficulty for higher earners is the Net Investment Income Tax, which under US domestic rules is generally not reduced by foreign tax credits, so a heavy dividend strategy can leave a residual US cost even when UK tax is high.

Retained profits are where Form 5471 does its work. If the profit was excluded under the high-tax election, it is not included annually and is taxed in the US only when later distributed. If it was included as net CFC tested income, it becomes previously taxed earnings and profits, tracked on Schedule P, and a later dividend out of it is not taxed again as a dividend, although currency gain or loss can arise when it is paid. Keeping Schedules J and P accurate year after year is what prevents the same profit being taxed twice when you finally extract it, perhaps on retirement or sale of the practice.

How Is Goodwill Treated When You Incorporate a Practice?

Many clinicians practised as sole traders or within a partnership before incorporating, then transferred the practice, including its goodwill, into a new company. On the UK side that transfer is a disposal for capital gains purposes, and the UK rules on corporation tax relief for goodwill acquired from a related individual are restrictive, so the company often cannot write off the goodwill it has bought from you. Clinicians also frequently leave the value owed for the goodwill as a credit on their director's loan account and draw it down tax-free over time.

The US side is easy to miss. A transfer of property by a US person to a foreign corporation is an outbound transfer governed by section 367, and since the 2017 Act goodwill and going-concern value transferred to a foreign corporation can produce US income for the transferor rather than a tax-free incorporation. The transfer is also reportable on Form 926 in the year it happens. A practice incorporated years ago without any of this on the US return is one of the most common catch-up cases we see.

What If the Practice Is a UK Partnership or LLP Instead?

Form 5471 applies to corporations. A practice run through a UK partnership or a UK limited liability partnership is generally treated as a foreign partnership for US purposes, so a US partner reports on Form 8865 instead, with their share of profit flowing onto the Form 1040 each year. The CFC rules, the tested income inclusion and the corporate high-tax election do not apply in the same way, so changing structure changes both the form and the timing of US tax.

Worked Example: A US Citizen Dentist and a Family-Owned Practice Company

The following is an illustration with invented figures, not a real client, and it assumes an exchange rate of $1.30 to £1 throughout. Dr Ellen Marsh is a US citizen living in England. She incorporated her private dental practice into a UK limited company, holding 75% of the ordinary shares herself, with her British husband holding the remaining 25%. The company's profit before her salary is £420,000. She takes a salary of £60,000 and the company pays dividends of £80,000 to the couple, £60,000 of it to her.

After her salary, the company's taxable profit is £360,000, above the £250,000 upper limit, so it pays corporation tax at the 25% main rate, £90,000, leaving roughly £270,000 of after-tax profit. Ellen is a Category 4 and Category 5a filer and ticks only Category 4. Her husband's 25% does not reduce the US picture: the company is a CFC on her shareholding alone, and his shares can be attributed to her under the family attribution rules in any case. Because he is not a US person, he has no Form 5471 of his own.

On her Form 1040, her £60,000 salary, about $78,000, is earned income sheltered by the Foreign Tax Credit for UK income tax paid under PAYE. Her £60,000 dividend, about $78,000, is a qualified dividend under the treaty with UK dividend tax available as a credit, although the Net Investment Income Tax may still apply. The retained profit, roughly £190,000, is where the election matters. On these illustrative numbers, with UK tax at 25% and no unusual timing differences, the effective rate on US principles is expected to exceed the threshold, so Ellen elects the high-tax exclusion and her share of the company's income drops out of net CFC tested income. Without the election, her 75% share would be included at ordinary rates, with no equipment carve-out to reduce it.

What Are the Penalties for Failing to File Form 5471?

The penalties are set out in the Form 5471 instructions at https://www.irs.gov/instructions/i5471 and apply whether or not any US tax was due. A $10,000 penalty applies for each annual accounting period of each foreign corporation for which a required Form 5471 is not filed, or is filed substantially incomplete. If the failure continues for more than 90 days after the IRS mails a notice, a further $10,000 applies for each 30-day period, up to a maximum of $50,000 of additional penalty per failure. Separately, failing to file can reduce the foreign taxes available for credit by 10%, with further 5% reductions for each three-month period the failure continues 90 days or more after notice.

The less visible cost is the statute of limitations. Section 6501(c)(8), at https://www.law.cornell.edu/uscode/text/26/6501, provides that where information required under section 6038 is not furnished, the period for assessing tax related to that information does not expire until three years after the IRS is furnished the information. If the failure was due to reasonable cause and not willful neglect, the extension is limited to the items related to the failure. In practice, a missing Form 5471 can keep an otherwise closed year open indefinitely, which is why we treat a late 5471 as a priority even when the company's profits were fully covered by UK tax.

How Do You Catch Up on Missed Form 5471 Filings?

The right route depends on whether you also have unfiled or understated US income. For a clinician resident in the UK, the IRS lists its options on https://www.irs.gov/individuals/international-taxpayers/us-taxpayers-residing-outside-the-united-states, and two are relevant to most practice owners.

The Streamlined Foreign Offshore Procedures, for non-willful taxpayers who meet the non-residency requirement, in broad terms having no US abode and spending at least 330 full days outside the US in one of the three most recent years. You file three years of delinquent or amended returns with the required information returns, including Form 5471, six years of FBARs, pay any tax and interest, and sign the Form 14653 certification of non-willful conduct. Compliant filers are generally not subject to failure-to-file, accuracy-related, information return or FBAR penalties, and the foreign version carries no miscellaneous offshore penalty.
The Delinquent International Information Return Submission Procedures, for taxpayers who have reported all their income and paid all tax, are not under civil examination or criminal investigation, and have not been contacted by the IRS about the missing returns. The IRS page at https://www.irs.gov/individuals/international-taxpayers/delinquent-international-information-return-submission-procedures, last reviewed in April 2026, directs that information returns such as Form 5471 be attached to an amended income tax return. You may attach a reasonable cause statement, but the IRS may assess penalties during processing without considering it, so you should expect to respond to correspondence.
Late FBARs for any year, whatever route you use for the 5471s, are filed electronically through FinCEN's BSA E-Filing System with the reason for late filing, or as part of a Streamlined submission. The former IRS Delinquent FBAR Submission Procedures page is no longer a live route.

An owner who reported every salary payment and dividend but never filed the 5471s usually fits the delinquent information return route. One who also missed the goodwill transfer, an inclusion or FBARs usually fits the Streamlined route better, because it settles income tax and information returns together.

What Should You Gather to Prepare Form 5471 for a Practice Company?

The company's UK statutory accounts and corporation tax computations for each year, with the CT600 and evidence of corporation tax paid
The share register and any share class rights, showing who owns what, including spouse and family holdings and any associate buy-ins
Payroll records for your director's salary and dividend vouchers for every distribution
The director's loan account ledger, including any balance created on the transfer of goodwill at incorporation
The incorporation documents and valuation of any goodwill or equipment you transferred into the company
A fixed asset register with dates and costs for chairs, imaging, other equipment and fit-out, for the US earnings and profits computation

Form 5471 for a UK dental or medical practice company is a recurring annual project rather than a one-off form. Prepared well, it records a company that UK tax has already taxed heavily, uses the high-tax election to keep retained profit out of current US income, tracks every pound of previously taxed earnings so it is never taxed twice, and closes the statute of limitations year by year. Prepared late or not at all, it leaves open years, fixed penalties and foreign tax credits at risk.