Introduction: What an HMRC Closure Notice Means for a US Filer
An HMRC closure notice is the formal letter that ends an HMRC enquiry, states the officer's conclusions and amends your Self Assessment return accordingly. For a purely British taxpayer, that letter closes one chapter. For an American living in Britain, it opens a second one on the other side of the Atlantic. Consequently, the day the notice lands, two separate tax systems begin moving at once.
Most guidance on this subject treats the question as a matter of domestic UK procedure. That guidance is accurate as far as it goes. However, it ignores the reader we act for every week. That reader is the dual-filing investor, owner or fund principal whose UK figures feed a US Form 1040. Therefore this guide covers the UK mechanics of an HMRC closure notice in full. It then follows the consequences through to the American return.
Why an HMRC Closure Notice Reaches Your US Return
An HMRC closure notice almost always changes the amount of UK tax you owe for a given year. Additionally, UK tax is the raw material of your US foreign tax credit. Therefore any movement in the UK figure is a foreign tax redetermination in American law. That is a defined event, and it carries mandatory reporting consequences most taxpayers never hear about.
The point deserves emphasis. Furthermore, the obligation runs in both directions. A closure notice that increases your UK liability may unlock a substantial US refund. Alternatively, one that reduces it can create an unexpected US debt on a year you considered settled years ago.
The Two Clocks That Start on the Same Day
The UK clock is short and unforgiving. Specifically, you have thirty days from the date of the notice to appeal. Meanwhile, the US clock runs far longer than most advisers assume. Understanding that asymmetry is the most valuable lesson an HMRC closure notice can teach a cross-border filer.
Notably, the two clocks reward opposite instincts. On the UK side, an HMRC closure notice rewards speed. On the US side, patience often pays better, because the window for a foreign tax credit claim stays open for a decade.
How an HMRC Enquiry Reaches a Closure Notice
HMRC cannot enquire into your return indefinitely from the outset. Rather, the department must open an enquiry within a defined window, and only then may it work towards a conclusion.
The Twelve-Month Window Under Section 9A
Under section 9A of the Taxes Management Act 1970, HMRC has twelve months from the date you actually filed to open an enquiry into a return delivered on time. Furthermore, if you filed late, the window instead runs to the quarter day following the first anniversary of delivery. The quarter days are 31 January, 30 April, 31 July and 31 October.
Miss that window and HMRC loses the enquiry route entirely. However, the department retains the separate power of discovery under section 29. We examine that alternative route in our guide to the HMRC discovery assessment. Importantly, offshore matters carry a twelve-year discovery limit rather than the ordinary four or six.
What HMRC Must Include in the Notice
A valid HMRC closure notice must do three things. Specifically, it must confirm that the officer has completed the enquiry. Additionally, it must state the conclusions and amend your self-assessment to match. HMRC's own Enquiry Manual at EM3852 sets out when an enquiry is legally complete.
That third element matters more than it sounds. Accordingly, a letter that merely announces a view without amending the return is not a closure notice at all. Therefore it does not start your appeal clock, and it does not close the enquiry.
Partial Closure Notices and the Embiricos Problem
Since November 2017, HMRC and taxpayers have been able to close discrete parts of an enquiry through a partial closure notice, introduced by Schedule 15 to Finance (No. 2) Act 2017. HMRC explains the regime at EM2160. In principle, a partial HMRC closure notice lets you appeal one contested issue while the rest of the enquiry continues.
In practice, the courts have narrowed that promise severely. In *Embiricos v HMRC*, the Court of Appeal restricted the partial HMRC closure notice sharply. HMRC cannot issue one on a domicile or remittance basis conclusion without also stating the tax due. You can read the judgment in full on [BAILII at [2022] EWCA Civ 3](https://www.bailii.org/ew/cases/EWCA/Civ/2022/3.html). Subsequently, the Supreme Court refused permission to appeal, so the position is settled.
Forcing HMRC to Close: The Section 28A Application
Enquiries drift. Consequently, Parliament gave taxpayers a remedy for extracting an HMRC closure notice, and it is stronger than most people realise.
Why the Burden Sits With HMRC
Under section 28A of the Taxes Management Act 1970, you may apply to the First-tier Tribunal at any point during an enquiry for a direction that HMRC issue a closure notice within a specified period. Crucially, the tribunal must give that direction unless HMRC satisfies it that reasonable grounds exist for refusing.
That allocation of burden is the whole point. Therefore HMRC, not you, must justify continued delay. HMRC's internal guidance at EM1980 addresses officers who face such an application. They must review whether their outstanding information requests remain reasonable and justified. The policy background sits in the Treasury consultation on tax enquiries closure rules.
What the Hitchins Case Changed
In *HMRC v Hitchins* [2024] UKUT 114, the Upper Tribunal upheld a direction requiring HMRC to close enquiries that had run since 2014 into a dividend paid in 2003. The tribunal characterised the remaining questions as an unfocused exercise without a reasonable basis. Consequently, the decision gives real weight to closure applications where an enquiry has lost its shape.
For US-connected clients, that authority is unusually valuable. Additionally, offshore enquiries are precisely the ones that sprawl, because the officer keeps finding new jurisdictions to ask about. An HMRC closure notice obtained by direction converts an open-ended investigation into a defined, appealable figure.
When a Closure Application Backfires
A closure application is not a free option. Specifically, forcing closure on incomplete information can produce a notice built on HMRC's least favourable assumptions. Moreover, *Embiricos* means a residence or domicile enquiry cannot be closed at all until the department can quantify the tax.
Therefore the timing of an HMRC closure notice application is strategic rather than procedural. Professional bodies including the Chartered Institute of Taxation and ICAEW publish useful commentary on current enquiry practice. In our experience, the application works best once HMRC holds everything it reasonably needs and has simply stopped moving.
The Thirty-Day Clock and Your Three Options
Once a valid HMRC closure notice arrives, you have thirty days to respond. Furthermore, that period runs from the date of the notice, not the date you opened the envelope.
Accepting the Amendment
You may simply accept the conclusions. Consequently, the amended self-assessment stands and any additional tax falls due within thirty days. For an American filer, acceptance is never the end of the matter, because the US consequences described below still require action.
Appealing and Postponing the Tax
Alternatively, you may appeal in writing to the officer, setting out your grounds. Importantly, an appeal does not by itself suspend payment. Therefore you should also apply to postpone the disputed tax, otherwise interest continues to accrue on an amount you are contesting. GOV.UK sets out the mechanics at its guide to tax appeals.
Statutory Review and the Tribunal
HMRC will usually offer a review by an officer not previously involved, ordinarily concluded within forty-five days. Subsequently, if the review goes against you, you have a further thirty days to notify the appeal to the First-tier Tribunal. Miss that deadline and you must apply for permission to appeal late, which the tribunal does not grant as a formality. HMRC's general compliance checks guidance collects the relevant factsheets.
What an HMRC Closure Notice Does to Your US Tax Return
Here the competing guidance stops entirely, and here the real money sits for our clients.
Foreign Tax Redetermination Under Section 905(c)
When the UK tax you previously claimed as a credit changes, US law treats that change as a foreign tax redetermination under section 905(c). Consequently, you must report it. The regulations at 26 CFR 1.905-4 require Schedule C of Form 1116 for the year the redetermination occurs. Notably, they apply whether or not your US tax actually moves.
That last point traps sophisticated filers regularly. Notably, taxpayers assume that no change in US liability means no filing obligation. However, the notification duty is freestanding, and failing it carries penalty exposure of its own. Our guide to the foreign tax credit and treaty relief explains how the credit interacts with the treaty.
The Ten-Year Window for a Foreign Tax Credit Claim
Most American taxpayers believe they have three years to amend a return. Generally that is right. However, a Form 1040-X claiming or increasing the foreign tax credit gets ten years. That period runs from the unextended due date of the year the foreign tax was paid or accrued. The IRS confirms this at Topic no. 856 and in its foreign tax credit guidance.
The practical effect is dramatic. Therefore an HMRC closure notice landing in 2026 can still generate a refund. That holds even where the UK year maps to US 2019 or 2020, long after the ordinary window shut. Above all, do not let a US preparer tell you the year is closed without checking the ten-year rule first.
The Accrual Trap and the Twenty-Four-Month Rule
Timing decides which US year receives the credit unlocked by an HMRC closure notice. Specifically, cash-basis filers claim the credit when they pay. Meanwhile, those electing accrual under section 905(a) relate it back to the year the income arose. Additionally, that election is irrevocable, so it deserves proper thought.
One further rule catches long enquiries. Foreign taxes accrued but unpaid twenty-four months after the US year closes are treated as refunded. Consequently, that rule retroactively strips the credit. Consequently, a protracted enquiry can quietly destroy relief you already claimed.
Residence and Domicile Enquiries: The Worldwide Disclosure Trap
An HMRC closure notice issued to a US-connected taxpayer disproportionately concerns residence, domicile and offshore income. Therefore the *Embiricos* rule bites hardest on exactly our client base.
Why a Partial Closure Notice Will Not Rescue You
Because HMRC must quantify the tax before it can issue any closure notice on a remittance basis conclusion, you cannot appeal the status question in isolation. Consequently, you must hand over full details of worldwide income and gains simply to reach an appealable HMRC closure notice. That is a considerable disclosure to make before you have tested the underlying point.
Reconciling the HMRC Schedule to Your Form 1040
For an American, that worldwide schedule is not new information. Rather, it is broadly the same dataset already reported to the IRS. Accordingly, the two must reconcile, and any divergence invites questions from both revenue authorities. Our guidance on exchange rates for US and UK tax explains how to keep the sterling and dollar figures defensible.
Furthermore, what you tell HMRC constrains what you can later certify to the IRS. Specifically, answers given during an enquiry sit uneasily with a subsequent non-wilful certification under the IRS Streamlined Filing Compliance Procedures. We examine that tension in our analysis of Schedule 36 information notices.
Case Study: A London Portfolio Manager and a Three-Year Enquiry
A US citizen managing a credit fund in London filed her 2020-21 UK return in January 2022. Subsequently, HMRC opened an enquiry in January 2023, within the twelve-month window, challenging her remittance basis claim.
The enquiry ran for three years without meaningful progress. Therefore, in early 2026, we applied to the tribunal under section 28A for a direction to close. HMRC issued the resulting HMRC closure notice in May 2026, increasing her 2020-21 UK income tax by £186,400 plus interest.
On the UK side, we appealed the HMRC closure notice and applied to postpone the disputed tax within the thirty-day window. Meanwhile, the American analysis produced the better outcome. She had elected accrual under section 905(a), so the additional UK tax related back to income already reported on her 2020 US return.
Translated at the 2020 average rate of 0.780, that £186,400 became roughly $238,974 of additional creditable foreign tax. Her 2020 US liability after credits had been $61,000. Consequently, a Form 1040-X recovered that $61,000 in full and generated approximately $177,974 of excess credit to carry forward.
The ordinary three-year deadline for 2020 had expired in April 2024. However, the ten-year foreign tax credit window runs to April 2031. Therefore the refund remained available, and we filed the mandatory Schedule C notification alongside it.
How TaxYork Can Help
TaxYork acts for high-net-worth Americans, dual nationals and business owners whose affairs span both systems. Consequently, we handle the UK enquiry and the US consequences as one engagement rather than two.
Our work on an HMRC closure notice starts by testing whether the notice is even valid. Subsequently, we handle the appeal, the postponement, the section 905(c) notification and any amended returns. Additionally, where an enquiry has stalled, we prepare and run the section 28A application. We also advise on US tax return preparation for expats and on FBAR and FATCA reporting where the enquiry exposes unreported accounts.
Where an enquiry reveals genuinely missed filings, we assess whether the IRS Streamlined Filing procedures remain available. We do that before anything is said to HMRC that would compromise them.
Conclusion
An HMRC closure notice is a deadline and an opportunity at the same time. On the UK side, thirty days is all you get, and the appeal and postponement applications must both be made. Meanwhile, on the US side, a decade-long window means substantial credits often remain recoverable.
Ultimately, the mistake we see most often is treating an HMRC closure notice as a purely British document. In reality, it changes a number that sits at the centre of your American return. Therefore the two responses must be planned together, and they must be planned quickly.
Contact Us
If HMRC has issued a closure notice, or an enquiry into your affairs has stalled, we can help you respond on both sides. An HMRC closure notice deserves a coordinated UK and US response. Please book a consultation with our cross-border team.
Email hello@taxyork.com or telephone 020 3488 8606.
Disclaimer
This article provides general information on UK and US tax procedure and does not constitute tax advice for any specific person or situation. Tax law changes frequently and its application depends on individual circumstances. You should obtain professional advice before acting on anything set out here. TaxYork accepts no liability for any loss arising from reliance on this article without such advice.