What is the penalty for filing Form 5471 late?

The penalty is $10,000 for each annual accounting period of each foreign corporation, under section 6038(b)(1). If the information is still not furnished 90 days after the IRS mails notice of the failure, a further $10,000 applies for each 30-day period or fraction of one, capped at an additional $50,000. The statutory maximum is therefore $60,000 per company per year, and it applies separately to each company and each year.

Do Form 5471 penalties apply if my UK company made no profit?

Yes. Section 6038 penalises the failure to furnish information, not the failure to pay tax, so a loss-making or dormant UK limited company attracts the same $10,000 as a profitable one. A genuinely dormant company may qualify for the summary filing procedure under Rev. Proc. 92-70, which involves filing page one of Form 5471 with a specific label in the top margin, but only if that procedure is actually followed.

Does a missed Form 5471 keep my entire US tax return open to audit?

Under section 6501(c)(8), the assessment period does not begin to run until the required information is furnished to the IRS, and a three-year period then starts. Until the missing Form 5471 is filed, the year it relates to remains open. A reasonable cause exception can confine that extension to the items related to the failure rather than the whole return, but it has to be established on the facts rather than assumed.

Can two US co-founders of one UK company file a single Form 5471?

A joint information return may be filed with the tax return of any one of the persons required to report for the same foreign corporation for the same period, although a Category 5b filer and a Category 5c filer cannot file jointly because their requirements differ. The obligation remains personal to each founder and the $10,000 penalty is imposed per person, per company, per year rather than shared, so a late or incorrect joint filing exposes both founders separately.

Can the IRS assess Form 5471 penalties automatically after the Farhy litigation?

In practice, yes. The D.C. Circuit reversed the Tax Court in Farhy v. Commissioner on 3 May 2024 and held that the IRS has authority to assess section 6038(b) penalties, and the Second Circuit reached the same conclusion in Safdieh v. Commissioner on 27 February 2026. The Tax Court maintains a contrary view, but with two circuits aligned and no split between them, a US founder should plan on the basis that the penalty can be assessed and collected administratively.

What is the best route to fix several missed years of Form 5471?

It turns on the non-residency test. If you had no US abode and were physically outside the United States for at least 330 full days in one or more of the last three years, and the failure was non-willful, the Streamlined Foreign Offshore Procedures cover three years of returns and six years of FBARs on a Form 14653 certification and waive information return penalties. If you do not qualify, delinquent Forms 5471 are attached to amended returns, but the IRS states that penalties may be assessed during processing without the attached reasonable cause statement being considered.

Form 5471 Late Filing Penalties: US Founders, UK Ltds

Form 5471 late filing penalties start at $10,000 for each annual accounting period of each foreign corporation you failed to report, and they apply whether or not your UK company turned a profit and whether or not you owed a single dollar of US tax. If the IRS mails a notice of the failure and the information is still not furnished 90 days later, a further $10,000 is charged for each 30-day period, or fraction of a period, capped at an additional $50,000. The statutory ceiling is therefore $60,000 per company per year, and it multiplies by every UK company you hold and every year you missed.

What Are Form 5471 Late Filing Penalties?

Form 5471 late filing penalties are the flat monetary sanctions imposed under Internal Revenue Code section 6038(b) when a US person who controls or holds a qualifying stake in a foreign corporation fails to furnish the required information on time. They are not calculated as a percentage of tax. They exist purely to enforce disclosure, which is why they land with full force on founders whose UK company was loss-making, dormant, or already fully taxed in the United Kingdom.

Three separate failures attract the same charge: not filing at all, filing after the deadline, and filing a return that omits required information. In practice the third is the one that catches otherwise well-organised founders. A Form 5471 submitted on time but missing the schedules your filer category requires can be treated as not filed, and the penalty clock is then measured from the original due date rather than from the date the incomplete form arrived.

Why a UK Limited Company Puts You Inside Form 5471

The starting point is entity classification, and most general guidance gets it slightly wrong. A UK public limited company is treated as a corporation per se for US federal tax purposes and cannot elect out. A UK private limited company is a foreign eligible entity, and because every member has limited liability it defaults to corporation treatment unless an election is made on Form 8832. Either way, the founder-owned London company sitting on your Companies House record is a foreign corporation in the eyes of the IRS from the day it was incorporated.

From there, the filer categories decide what you owe. A UK company becomes a controlled foreign corporation, or CFC, when US shareholders who each own at least 10 percent of vote or value together own more than 50 percent of the company. Two US co-founders holding 30 percent each of a London startup create a CFC between them, even though neither one controls it individually.

Category 4 applies where a US person had control of the foreign corporation, meaning more than 50 percent of total voting power or more than 50 percent of total value, during its annual accounting period.
Category 5 applies where a US shareholder owned stock in a CFC on the last day of the year in which the company qualified as a CFC, and splits into sub-categories 5a, 5b and 5c.
Category 3 is triggered by the transaction rather than the holding: acquiring stock that takes you to 10 percent, adding a further 10 percent, or disposing down below the threshold.
Category 2 catches US officers and directors when a US person acquires a qualifying stake, which frequently applies to a founder who sits on the board of a company they do not majority own.
Category 1 applies to US shareholders of section 965 specified foreign corporations, with sub-categories 1a, 1b and 1c.

When Does Form 5471 Become Late?

Form 5471 is not filed on its own and has no independent deadline. It is attached to your income tax return and is due when that return is due, including extensions. A US founder living in London receives an automatic two-month extension to 15 June without asking for it, and can push the date to 15 October by filing Form 4868 before the automatic extension expires. Interest still accrues on any tax unpaid at the regular April due date, so the extension buys filing time rather than payment time.

The consequence is blunt. If your Form 1040 goes in late, or goes in on time without the Form 5471 attached, the information return is late from the same moment. There is no separate grace period and no small-company exception.

How the $10,000 Form 5471 Penalty Escalates

An initial $10,000 penalty applies for each annual accounting period of each foreign corporation for which the required information was not furnished.
If the information is still not filed within 90 days after the IRS mails notice of the failure, an additional $10,000 applies for each 30-day period, or fraction of one, that the failure continues.
That additional penalty is limited to a maximum of $50,000 for each failure, so the ceiling is reached after five further 30-day periods.
Separately, section 6046 supports a penalty under section 6679 of $10,000 for each failure for each reportable transaction, with the same 90-day trigger and the same $50,000 cap on continuation.
Criminal penalties under sections 7203, 7206 and 7207 may apply where the conduct goes beyond mere lateness.

Nothing in that structure is scaled to the size of the business. The same $10,000 attaches to a two-person UK consultancy as to a company with eight figures of turnover, which is precisely why the penalty is so often disproportionate to the underlying tax at stake.

A Worked Example: Three Missed Years on One London Company

Take a US citizen who incorporated a UK private limited company in 2021, owns 100 percent of the shares, and files a US return each year without a Form 5471 because the company was reinvesting and paid no dividends. Three annual accounting periods go unreported: 2021, 2022 and 2023. The initial exposure is three separate $10,000 penalties, or $30,000, before any notice has been issued and before any UK tax question is even reached.

Assume the IRS then mails a notice of the failure for each year and the founder, believing the matter is not urgent because no US tax was due, does not respond for eight months. The 90-day window passes, then five further 30-day periods run before the cap bites. Each year picks up the full additional $50,000. The three years now carry $60,000 each, a statutory maximum of $180,000 on a company that never distributed a penny to its owner. Those figures are not a worst case invented for effect. They are simply the arithmetic of section 6038(b) applied three times over.

The Quiet Cost: Losing Credit for UK Corporation Tax You Already Paid

The monetary penalty is the headline, but section 6038(c) is often the larger number for a profitable UK company. A US person who fails to furnish the required information within the prescribed time suffers a reduction of 10 percent of the foreign taxes available for credit. If the failure continues 90 days or more after the IRS mails notice, a further 5 percent reduction applies for each three-month period. The statute does impose a limitation on how far that reduction can ultimately run, but the direction of travel is unmistakable.

This lands hardest on exactly this audience. UK Corporation Tax runs at a main rate of 25 percent on profits above 250,000 pounds, with a small profits rate of 19 percent where profits are 50,000 pounds or less and marginal relief between the two, for accounting periods from 1 April 2023. Those thresholds are reduced for short accounting periods and by the number of associated companies. That UK tax is the credit standing between a US founder and genuine double taxation, so cutting it by 10 percent and then in further 5 percent increments converts a paperwork failure into a permanent cash cost.

Why One Late Form 5471 Keeps Your Entire Return Open

Section 6501(c)(8) is the provision that turns a single missed form into an open-ended problem. The assessment period does not begin to run until the required information is furnished to the IRS, and only then does a three-year period start. Until you file the missing Form 5471, the year it relates to is not closed, and the exposure is not necessarily confined to the foreign corporation itself. A reasonable cause exception can narrow the extension so that it reaches only the items related to the failure rather than the whole return, but that relief has to be established on the facts rather than assumed.

The Co-Founder Trap Most Guides Miss

Where several US persons must furnish information for the same foreign corporation for the same period, the instructions permit a joint information return filed with the tax return of any one of them. Founders read this as a cost saving and stop reading there. The obligation under section 6038 is personal to each US person, and the penalty is imposed per person, per foreign corporation, per year. It is not divided between the shareholders because they agreed to share a form.

If the designated founder files late, both founders are late; a joint return only discharges the obligation once the information is actually furnished.
A Category 5b filer and a Category 5c filer cannot file a joint Form 5471, because their filing requirements are not the same.
The joint filer item on the form must correctly identify the person filing and the persons covered; an error there can leave a co-founder unreported even though a form was submitted for the company.
Departures matter. A co-founder who exits and whose shares are bought back may have a Category 3 disposition to report in the year of exit, independently of anyone else's filing.

The Accounting Reference Date Mismatch That Makes UK Founders Late

This is the mechanical cause of most late filings in this population, and general guidance does not address it. Companies House sets a UK company's accounting reference date by reference to incorporation, so a company formed in September carries a 30 September year end rather than 31 December. Form 5471 reports the foreign corporation's annual accounting period, but it travels on a US return governed by the calendar year, and the two calendars do not line up.

Now overlay the UK deadlines. Annual accounts are not due at Companies House until nine months after the financial year end, Corporation Tax is payable nine months and one day after the accounting period ends, and the Company Tax Return is not due to HMRC until twelve months after that period ends. A founder with a 30 September year end can easily have no finalised UK accounts at all when the US return falls due, and files an estimated or partial Form 5471 that is later treated as substantially incomplete. Aligning the accounting reference date with the calendar year, or building the US schedules from management accounts instead of waiting for statutory accounts, removes the problem at source rather than managing it every spring.

Can the IRS Assess Form 5471 Penalties Automatically?

For a period this was genuinely uncertain, and some founders sat on missed years in the hope the question resolved in their favour. The Tax Court held in Farhy v. Commissioner that the IRS had no authority to assess section 6038(b) penalties administratively, which would have forced the government to sue in order to collect them. On 3 May 2024 the D.C. Circuit reversed that decision and held the IRS does have assessment authority. On 27 February 2026 the Second Circuit reached the same conclusion in Safdieh v. Commissioner. The Tax Court has continued to maintain its own contrary position, but with two appellate circuits now aligned and no split between them, the working assumption for a US founder should be that the penalty can be assessed and collected without the IRS going to court.

How to Fix Late Form 5471 Filings

The Streamlined Foreign Offshore Procedures, where the conduct was non-willful and you meet the non-residency test: no US abode and physical presence outside the United States for at least 330 full days in any one or more of the last three years. The submission covers three years of returns and six years of FBARs, is certified on Form 14653, carries no miscellaneous offshore penalty, and waives information return penalties including those on Form 5471.
The Delinquent International Information Return Submission Procedures, where the returns and the tax were otherwise correct and only the information return is missing. Delinquent Forms 5471 are attached to an amended income tax return, and a reasonable cause statement may be attached to each one.
A standalone reasonable cause position, set out in writing and supported by evidence of ordinary business care and prudence, where neither route above fits the facts.

The delinquent return route carries a caveat that founders should read closely before choosing it. The IRS states that during processing of a delinquent information return, penalties may be assessed without considering the attached reasonable cause statement. The reasonable cause argument then has to be run after assessment rather than before it, which is a materially weaker posture than the Streamlined route, where eligible information return penalties are waived from the outset. It is also worth knowing that first-time abatement relief generally does not extend to event-based international information return penalties of this kind, so it is rarely the answer here.

Does a Dormant UK Company Still Need Form 5471?

Yes, and this catches founders who incorporated a UK company to reserve a trading name or hold intellectual property and never traded through it. The filing obligation follows ownership, not activity. Rev. Proc. 92-70 does provide a summary filing procedure for a dormant foreign corporation: the filer attaches page one of Form 5471 for each dormant company to the regularly filed income tax return, with the top margin labelled to state that it is filed pursuant to Rev. Proc. 92-70 for dormant foreign corporations. Complying with that procedure satisfies the obligations under sections 6038(a)(1), 6038(a)(4) and 6046(a)(3). Filing nothing at all does not, and the $10,000 applies to the shell exactly as it applies to the trading company.

What US Founders of UK Companies Should Do Now

Map every UK entity in which you hold 10 percent or more, including dormant companies and any holding company sitting above the trading entity, and identify your filer category for each year separately.
Check whether the same UK company also drives an FBAR on FinCEN Form 114, a Form 8938, a Form 8992 for net CFC tested income, or a Form 926 for the capital you contributed on incorporation, because the exposures compound rather than overlap.
Reconcile your Companies House accounting reference date against the US calendar year and decide whether changing it is cheaper than managing the mismatch indefinitely.
If years are missing, quantify both the section 6038(b) penalty and the section 6038(c) credit reduction before choosing a route, because the right route turns on whether you meet the 330-day test.
Do not file a partial Form 5471 in order to stop the clock. A substantially incomplete return does not reliably start the section 6501(c)(8) period running, and it can extend the exposure rather than end it.

The pattern we see repeatedly among US founders in London is not evasion. It is a founder who paid full UK Corporation Tax on time, owed little or nothing in the United States after credits, and had no idea that a disclosure form carried a five-figure penalty of its own. The compliance fix is almost always cheaper than the penalty, and it is dramatically cheaper before the IRS mails the notice that starts the 90-day escalation.