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US UK Accountants.

Accountants for US and UK returns, prepared as one job

Two tax systems, two calendars, one set of facts. We prepare the American and British filings together, so the credits, elections and disclosures on each side agree with the other before anything is submitted.

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The Problem.

Why two separate accountants rarely works

The arrangement looks sensible: a British accountant for the British return, an American preparer for the American one. It holds together until the two returns have to agree with each other.

Foreign tax credits are the usual casualty. Each country gives credit for tax paid to the other, but only in the right direction and the right order. Two firms working separately tend to each assume the other went first.

The same happens with elections. Excluding foreign earnings on the US return can wipe out a refundable credit worth more than the exclusion saved, as our guide to the child tax credit abroad sets out. Nobody notices when neither adviser sees both returns.

  • Credits claimed in the wrong direction, or twice
  • Elections on one return that undermine the other
  • Income apportioned differently across two tax years
  • Exchange rates applied inconsistently between filings
  • Disclosure forms nobody took responsibility for
  • Deadlines met individually but planned for by neither

The Year.

The transatlantic tax calendar

Eight dates matter to most cross-border clients. Weekends push a date to the next working day, so check the exact day each year rather than assuming the fifteenth or the thirty-first.

Combined US and UK filing calendar for cross-border taxpayers
DateWhat falls dueNotes
5 AprilUK tax year endsP60s and pension statements follow over the next two months
15 AprilUS filing and payment datePayment is due here even when filing is extended
15 JuneAutomatic US extension for people abroadGranted automatically; no form required
31 JulyUK second payment on accountWhere the previous year's bill required payments on account
5 OctoberUK Self Assessment registration deadlineFor anyone newly within Self Assessment
15 OctoberExtended US filing date and FBAR deadlineBoth usually handled in the same sitting
31 OctoberUK paper filing deadlineOnline filers have until January
31 JanuaryUK online filing and balancing paymentPlus the first payment on account for the new year

Our guide to US tax deadlines for expats covers the American dates in detail, including the extension that moves filing but never payment.

The Work.

What each side of the engagement covers

United States

United Kingdom

Complex positions, missed years and treaty questions sit on our US UK tax specialists page, which covers the advisory side of the same relationship.

Switching.

Moving to us from another firm

  1. 01Ask your current firm for the last three years of filed returns and computations.
  2. 02Request any carryforwards: unused foreign tax credits, capital losses and depreciation schedules.
  3. 03Collect the disclosure forms already filed, including FBAR confirmations.
  4. 04Give written authority for us to contact your previous adviser.
  5. 05Agree the fixed fee and scope before any work begins.
  6. 06Time the move for shortly after a filing deadline rather than during one.

Questions, Answered.

Working with US UK accountants

What do US UK accountants actually handle?
Both countries' annual filings from one set of records: the US Form 1040 with its schedules and disclosure forms, and the UK Self Assessment return. The same salary, interest and gains appear on both, measured on different dates, so the work is as much reconciliation as preparation.
Why not use one accountant in each country?
Many people start that way, and it works until the two returns disagree. Neither adviser sees the whole picture, foreign tax credits get claimed in the wrong direction, and elections made on one return quietly undermine the other. Coordinating two firms usually costs more than using one.
Which return should be prepared first?
Usually the one whose tax feeds the other's credit claim, which depends on your income mix and residence. That order is a decision rather than an accident, and it is why both returns are best prepared together rather than months apart by separate firms.
How do the two tax years line up?
They do not. The UK year ends on 5 April and the US year on 31 December, so a single salary is split differently on each return. Apportioning income and tax across that mismatch is routine work for a cross-border accountant and a frequent source of errors elsewhere.
What drives the fee for cross-border accounts?
Form count rather than income, in most cases. A straightforward employee with one UK salary is far quicker than someone holding funds, a rental, a company or unreported years. Ask for a fixed fee in writing after a scoping conversation, with the forms it covers listed.
How do I switch accountants mid-relationship?
Ask your current firm for your filed returns, computations and any carryforwards, then give written authority for the new firm to contact them. Professional courtesy handles the rest. The best time to move is shortly after a filing deadline, not during one.
Do you work with businesses as well as individuals?
Yes. A UK limited company owned by a US person brings Form 5471 and possible tax on undistributed profits, while a US business with UK activity raises permanent establishment questions. Both sit alongside the owner's personal returns rather than separately from them.
What if I am behind on filings?
That is common and usually fixable. Several catch-up routes carry no penalty where the failure was not deliberate, but eligibility depends on residence, what was filed before, and whether the IRS has already been in touch. Take advice before filing anything.

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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