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US UK Tax Specialists.

US tax specialists for people who file in both countries

A US UK tax specialist prepares both returns from one set of facts, so the elections made in America still make sense in Britain. This page sets out what that work covers, when a domestic accountant is not enough, and how to judge whether a firm can genuinely handle both systems.

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The Work.

What a US UK tax specialist actually does

The filings themselves are only part of it. A US citizen in Britain files a Form 1040 with the IRS and, usually, a Self Assessment return with HMRC. Each return contains the same income, measured on different dates, in different currencies, under different rules.

The specialist work sits in the joins. Which country taxes each source first, whether to exclude foreign earnings or credit the tax already paid, and which disclosures the holdings trigger. Those choices interact, and they are far harder to unwind than to get right.

Our US UK accountants page covers the annual compliance relationship in more detail, including the transatlantic filing calendar.

  • Both returns prepared together, from one set of documents
  • The exclusion and the foreign tax credit modelled before choosing
  • Disclosure forms: FBAR, Form 8938, 5471, 3520 and 8621
  • Treaty positions claimed and disclosed where they apply
  • Catch-up filings sequenced so the relief survives
  • A single diary covering both countries' deadlines

The Signals.

When a domestic accountant is not enough

You hold UK funds, an ISA or investment bonds

Most UK funds are PFICs for US purposes, which brings punitive rates and a Form 8621 for each holding. An ISA shelters nothing in America.

PFIC reporting

You have a UK pension, or a US 401(k) in Britain

The treaty protects growth on both sides, but only when it is claimed properly. Lump sums and regular payments follow different rules.

Pensions & retirement

You are self-employed or run a limited company

A UK company owned by a US person is a controlled foreign corporation, with Form 5471 every year and tax on profits you have not drawn.

Business & corporate tax

You have missed US filings or FBARs

Catch-up routes exist and mostly carry no penalty, but eligibility turns on facts that need testing before anything is filed.

Streamlined filing

You are moving in either direction

Arrival and departure dates decide which country taxes what. Most of the useful planning closes the day you land.

Moving across the Atlantic

You hold a green card outside America

The status keeps you in the US tax system until it formally ends, whatever the plastic card says or where you actually live.

Green card holders in the UK

Due Diligence.

How to judge a US UK tax specialist

Cross-border tax is an unregulated description, so the title alone tells you nothing. These are the questions worth asking any firm, including this one, before you engage.

Questions to ask a cross-border tax firm and what a good answer looks like
What to askWhat a good answer looks like
Who signs the US return?A named Enrolled Agent or CPA with a current PTIN, not an unnamed back office.
Who handles the UK side?Someone with ACA, ACCA or CTA membership, working on your file rather than referred out.
Are the two returns prepared together?Yes, with the elections on one modelled against the other before either is filed.
How is the fee set?A fixed fee agreed in writing after scoping, with the forms it covers listed.
What happens if I have missed years?An eligibility review first, then a route recommendation, before anything is filed.
Is there professional indemnity cover?Yes, and it explicitly covers cross-border work rather than domestic filings only.

Specialist Areas.

Where cross-border expertise earns its fee

IRS streamlined filing

Catching up on missed years without penalties.

FBAR & FATCA reporting

Account disclosures and the thresholds that trigger them.

Double tax treaty relief

Stopping the same income being taxed twice.

Expatriation & exit tax

Renouncing, or giving up a long-held green card.

Property & capital gains

Selling a home or rental on either side.

Trusts & estates

Foreign trusts, gifts and inheritances.

All Services

Questions, Answered.

Choosing a US UK tax specialist

What is a US UK tax specialist?
Someone who prepares and advises on both tax systems as one position, rather than one country in isolation. That means the US return, the UK return, the disclosure forms each country requires, and the treaty positions that stop the same income being taxed twice. The value sits in the coordination as much as the individual filings.
Do I actually need a specialist, or will any accountant do?
If your affairs sit entirely in one country, a domestic accountant is usually fine. Once UK funds, pensions, company ownership, missed filings or a move between countries enter the picture, the interactions decide your bill. Those interactions are where single-country advice tends to cost people money.
Can one firm really file in both countries?
It can, provided it holds the right credentials on both sides and prepares the returns together rather than sequentially. Ask directly who prepares the US return, who prepares the UK return, and whether the elections on one are modelled against the other before either is filed.
What qualifications should I look for?
On the US side, an Enrolled Agent or CPA with a current PTIN can prepare and sign returns. On the UK side, look for ACA, ACCA or CTA membership. Ask for the registration numbers, and check that professional indemnity cover is in place for cross-border work specifically.
How are fees usually structured?
Good practice is a fixed fee agreed in writing before any work starts, based on a scoping conversation about your forms and your situation. Hourly billing on cross-border work makes budgeting difficult, because the form count rather than the tax often drives the time involved.
Can everything be handled remotely?
Yes. Cross-border work is document-driven, so secure upload, video calls and electronic signatures cover almost every case. What matters far more than location is whether the firm handles both systems and can explain how your two returns fit together.
When in the year should I make contact?
Earlier than most people do. The UK tax year ends on 5 April and the US year on 31 December, so documents arrive on two different calendars. Planning conversations are worth having before the year ends, because most elections cannot be revisited afterwards.
What if I have not filed for several years?
That is a common starting point rather than an unusual one. Several catch-up routes exist, and the penalty-free ones are open to people whose failure was not deliberate. Take advice on eligibility before filing anything, because the order of the fix protects the relief.

Get in Touch

If you live, work or hold assets across the US and UK, we would welcome the conversation. Tell us what you have and we will come back with the scope and a fixed fee in writing — at no cost.

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