Rates, thresholds and deadlines on this page were checked against the official US and UK sources linked throughout on 1 October 2026. Tax rules change; confirm anything you intend to act on, or ask us.
# Tax Specialists for US and UK
Tax specialists for US and UK filings do one thing a very good single-country accountant cannot: they hold both returns in view at once and take a single consistent position across them. A US citizen in London and a British national in Chicago each answer to two authorities with different tax years, different definitions of residence, and different views of what counts as income. The work is not filing twice. It is making the second return agree with the first, so that relief which is genuinely available is actually claimed and nothing is reported two different ways.
Below: which returns and forms apply to which situations, three computations line by line, the 2025 UK reforms that can create a US bill with no credit to set against it, and ten questions that will tell you in twenty minutes whether the person across the table has done this before. UK figures are for 2026/27 and US figures for tax year 2026 unless stated, verified on 1 October 2026; the UK Budget falls on 28 October 2026, so treat the UK rates block as dated rather than permanent.
Who needs a US and UK tax specialist
Most people arrive from one of seven positions. Americans in the UK file a UK return or pay through PAYE and file a US Form 1040, because the US taxes citizens on worldwide income wherever they live. Britons in the US become US tax residents by green card or day count, at which point the US taxes their UK rents, dividends and pensions too. Dual citizens and accidental Americans usually find out when a UK bank asks them to certify their status under FATCA; the route back is a catch-up programme, not one late return, as our accidental American page explains. Green-card holders who have left remain US tax residents until the card is formally abandoned. Non-resident landlords owe UK tax on UK rents and may suffer withholding first. People mid-move need the two tax years sequenced deliberately — see our residence explainer. Cross-border business owners move into a different engagement: controlled foreign company rules, Forms 5471 or 5472, corporate residence and permanent establishment risk, on our US/UK cross-border business tax page.
The decision table: which returns and forms apply to you
We build this table for every new cross-border client before any work starts. "Threshold" refers to the reporting thresholds set out later on this page; every row has exceptions.
| Your situation | US 1040 | FBAR | Form 8938 | UK Self Assessment | Treaty claim likely | Who signs |
|---|---|---|---|---|---|---|
| US citizen, UK resident, PAYE employee | Yes | If over threshold | If over threshold | Often not, if PAYE only | Form 1116 credit | CPA/EA + ACCA |
| US citizen, UK resident, self-employed | Yes, with SE tax | If over threshold | If over threshold | Yes — SA100, SA103 | Totalization certificate | CPA/EA + ACCA |
| Dual US/UK citizen in the UK | Yes | If over threshold | If over threshold | Depends on income | Credit; no tie-breaker against citizenship | CPA/EA + ACCA |
| Accidental American, never filed | Yes, via catch-up route | Usually six back years | For the years filed | Depends on income | Non-willfulness certification | CPA/EA + ACCA |
| Green-card holder who left the US | Yes, until card abandoned | If over threshold | If over threshold | Yes, if UK resident | Article 4 tie-breaker, on Form 8833 | CPA/EA + ACCA |
| Briton, US resident, UK rental income | Yes, Schedule E | If over threshold | If over threshold | Yes — SA105, SA109 | Article 6; UK tax credited | CPA/EA + ACCA |
| Non-resident landlord, no US link | No | No | No | Yes — SA105, SA109 | Personal Allowance claim | ACCA |
| US citizen owning a UK limited company | Yes, plus Form 5471 | If over threshold | If over threshold | Yes, if UK resident | Subpart F and GILTI first | CPA/EA + ACCA |
Two features of that table matter. A US return and a UK return require different licensed sign-offs, and one firm holding both licences is not the same as one person holding both. And the FBAR goes to the Treasury rather than with your tax return, so a preparer who thinks only in terms of the 1040 can miss it entirely.
Why the US and UK systems collide
Almost every cross-border problem traces back to one of three mismatches.
Citizenship versus residence. The UK taxes on residence: leave, and after a clean break its claim on your foreign income ends. The US taxes on citizenship, for life, wherever you live and whether or not you have ever set foot there. That asymmetry is why "I moved, so I stopped filing" is the most expensive assumption in this field.
Two tax years that do not line up. The US year is the calendar year; the UK year runs 6 April to 5 April, so one UK salary straddles two US years. Since the foreign tax credit works year by year, UK tax on February earnings must be allocated to the right US year before it can be credited. Our rule: prepare the UK position first where UK tax is the larger, because the US return needs the UK figure. Where the UK liability is not yet quantified, use the extensions — US citizens abroad get an automatic two-month extension to 15 June and can reach 15 October with Form 4868, though interest still runs from the original due date. UK side: register by 5 October, file and pay by 31 January, payment on account the following 31 July.
The saving clause. The US–UK double taxation convention allocates taxing rights. Article 4 decides residence where both countries claim you, running a cascade: permanent home, then centre of vital interests, then habitual abode, then nationality, then agreement between the authorities. Article 6 gives the country where land sits the right to tax income from it. Article 17 covers pensions and social security, Article 24 is the relief-from-double-taxation article behind the foreign tax credit, and Article 26 is the mutual agreement procedure.
Then Article 1(4) — the saving clause — lets each country tax its own citizens "as if this Convention had not come into effect", subject to a short list of exceptions in Article 1(5) that includes Article 17(1)(b), 17(3) and 17(5), Article 18(1), and Articles 24, 25 and 26.
That list is where money is won and lost. Article 17(2) says a lump sum from a pension scheme in one country, owned by a resident of the other, is taxable only where the scheme sits — which looks as though it shields a UK pension commencement lump sum from US tax. But 17(2) is not in the Article 1(5) list. A US citizen resident in the UK cannot use it to exclude a UK lump sum from a US return. Advisers who quote 17(2) without checking 1(5) reach the wrong answer, and it is an expensive one. Our treaty tie-breaker explainer goes further.
Are you UK tax resident? The Statutory Residence Test
UK residence is a statutory test decided tax year by tax year, and the most common single error we see is assuming a 183-day rule settles it.
The test runs in a fixed order. The automatic overseas tests come first, and meeting any one makes you non-resident for the year. HMRC's guidance says you are automatically non-resident if you spent "fewer than 16 days in the UK (or 46 days if you have not been a UK resident for the 3 previous tax years)", or worked abroad full time averaging at least 35 hours a week while spending fewer than 91 UK days, no more than 30 of them working days. HMRC's manual at RFIG20140 states the work-abroad version more precisely: sufficient hours overseas, no significant breaks, fewer than 31 days doing more than three hours' UK work, fewer than 91 UK days.
Only then do you reach the automatic UK tests: 183 or more UK days in the year; an only home in the UK for 91 days or more in a row with at least 30 days spent there; or full-time UK work across any 365-day period touching the year.
The five ties. If no automatic test decides it, the sufficient ties test does: family, accommodation, work, the 90-day tie, and the country tie, which is available only to people leaving the UK. Fewer UK days means more ties required. HMRC sets the combinations out in two tables at RFIG20520 — one for people UK resident in at least one of the three preceding tax years, one for those who were not. We deliberately do not reproduce those bands. HMRC corrected the day counts in its ties guidance during 2026, the older guidance note predates the correction, and a table copied from the wrong version of a source is worse than no table. Read them at the link and have the conclusion checked.
Split-year treatment. In the year you arrive or leave, the year is normally split into a non-resident and a resident part, so UK tax on foreign income applies only to the resident portion. HMRC is explicit that you lose this if you "live abroad for less than a full tax year before returning to the UK". It is claimed, not automatic.
The "five-year rule". Leaving the UK, realising gains or taking distributions while away, then returning can pull that income into a UK return on your return. The temporary non-residence rules bite where you had sole UK residence in four or more of the seven tax years before the year of departure and your period of non-residence is five years or less; HMRC's manual at RFIG21510 confirms the period must exceed five years to escape them. The trap is the unit of measurement: it runs on UK residence periods and tax-year dates, not calendar anniversaries of your departure flight. These rules also changed from 6 April 2026, so a departure planned on older advice should be re-checked.
Non-residents often still file. UK-source income remains taxable — most commonly UK rent, but also UK employment duties and certain pensions. A non-resident landlord files the SA100 with SA105 and SA109, and cannot file the SA109 through HMRC's own online service, which is one reason those returns arrive with an agent.
The rates and thresholds this page uses
Every UK figure sits in this one dated block, verified on 1 October 2026 for the 2026/27 tax year (6 April 2026 to 5 April 2027). The UK Budget is 28 October 2026 — check this block before relying on any number after that date.
| Item | 2026/27 | Source |
|---|---|---|
| Personal Allowance | £12,570 | gov.uk — Income Tax rates and Personal Allowances |
| Allowance taper | reduced by £1 per £2 of adjusted net income above £100,000; nil at £125,140 | as above |
| Basic rate | 20% on the first £37,700 of taxable income | as above |
| Higher rate | 40% to £125,140 | as above |
| Additional rate | 45% above £125,140 | as above |
| Employee National Insurance | 8% from £12,570 to £50,270; 2% above | gov.uk — rates and thresholds for employers 2026 to 2027 |
| Dividends | £500 allowance; 10.75% / 35.75% / 39.35% | as above |
| ISA / Junior ISA | £20,000 / £9,000 | gov.uk |
| Property and trading allowances | £1,000 each | gov.uk |
US figures are for tax year 2026, from the IRS inflation adjustments under Revenue Procedure 2025-32: a single-filer standard deduction of $16,100, and bands of 10% to $12,400, 12% to $50,400, 22% to $105,700 and 24% to $201,775. The foreign earned income exclusion is $132,900 for 2026 and was $130,000 for 2025, per the IRS exclusion guidance.
Exchange rates cannot be published in advance. The examples use an illustrative $1.30 = £1 purely so the arithmetic is followable. A real return uses a consistent yearly average rate, or spot on the day of receipt for one-off items, documented in the file.
The three examples that follow are constructed illustrations, not clients, and the names are invented.
Worked example 1 — a £75,000 London employee: credit or exclusion?
Maya is a US citizen, UK resident, employed in London on £75,000 with no other income.
The UK side. Her income is below £100,000, so she keeps the full allowance.
| Line | Working | Amount |
|---|---|---|
| Salary | £75,000 | |
| Personal Allowance | (£12,570) | |
| Taxable income | £62,430 | |
| Basic rate | £37,700 × 20% | £7,540 |
| Higher rate | £24,730 × 40% | £9,892 |
| UK income tax | £17,432 | |
| Employee NI | 8% then 2% | £3,511 |
UK income tax is 23.2% of gross. The National Insurance is not an income tax, which matters next.
The US side, before relief. £75,000 at $1.30 is $97,500.
| Line | Working | Amount |
|---|---|---|
| Gross income | $97,500 | |
| Standard deduction | single, 2026 | ($16,100) |
| Taxable income | $81,400 | |
| 10%, 12% and 22% bands | $1,240 + $4,560 + $6,820 | |
| US tax before relief | $12,620 |
Route A — the foreign tax credit. £17,432 of UK income tax converts to $22,662. That is creditable; her National Insurance is not, being a social security contribution rather than an income tax. Claimed on Form 1116, the credit is capped at the US tax on foreign-source income — here effectively all of it. US tax before credit $12,620, credit $12,620, US tax payable nil, and $10,042 of unused foreign tax which under section 904(c) is carried back one year and then forward for up to ten.
Route B — the exclusion. Her $97,500 sits inside the $132,900 exclusion, so all of it is excluded on Form 2555. Taxable income nil, US tax payable nil as well.
So which? Both give nil this year, which is exactly why this decision is so often made badly. The credit wins on everything that is not this year's bottom line:
- The carryforward is a real asset. The credit route banks $10,042; the exclusion banks nothing. In a year with a bonus, a share vest or US workdays, that stored credit is what prevents a US bill.
- Excluding income forfeits credits. The Form 2555 instructions are explicit that you cannot take the additional child tax credit or the earned income credit if you claim the exclusion — which, for a family with children, can exceed the exclusion's value.
- The election is sticky. After revoking, "you can't claim the exclusion(s) for your next 5 tax years without the approval of the IRS."
- It does not touch self-employment tax. See below.
The exclusion earns its place where UK tax is low or nil relative to US tax: a low UK salary, a year of UK non-residence, or earned income the UK barely taxes. In a higher-rate country with a comparable base, the credit usually wins. Our FEIE versus foreign tax credit comparison covers the edge cases; check the two halves with our UK calculator and US calculator.
Worked example 2 — £110,000, the 60% band, and your US credit
Daniel is a US citizen resident in the UK earning £110,000. He has walked into the UK's least-advertised marginal rate.
The taper. At £10,000 above £100,000, his allowance drops by £5,000 to £7,570.
| Line | Working | Amount |
|---|---|---|
| Salary | £110,000 | |
| Reduced Personal Allowance | £12,570 − £5,000 | (£7,570) |
| Taxable income | £102,430 | |
| Basic rate | £37,700 × 20% | £7,540 |
| Higher rate | £64,730 × 40% | £25,892 |
| UK income tax | £33,432 |
Proving the 60%. Run the same computation at exactly £100,000: full allowance, taxable income £87,430, tax of £7,540 + £19,892 = £27,432. So £10,000 of extra salary produced £6,000 of extra UK income tax — a 60% marginal rate, not a figure of speech. With 2% employee National Insurance on the same slice, the combined marginal cost is 62%.
The US side. £110,000 at $1.30 is $143,000; less $16,100 gives taxable income of $126,900. The 10%, 12%, 22% and 24% bands produce $1,240 + $4,560 + $12,166 + $5,088 = $23,054 before relief. His £33,432 of UK tax converts to $43,462 of creditable foreign tax, which wipes out the US liability and leaves roughly $20,408 of excess credit. Counter-intuitively, the 60% band is what keeps him out of US tax: an unusually high UK effective rate generates an unusually large credit.
The cross-border half nobody joins up
The standard UK fix is salary sacrifice. Sacrificing £10,000 into a workplace pension restores £5,000 of allowance and saves the full £6,000 of income tax plus £200 of National Insurance. On the UK side, close to free money. For a US citizen there are two consequences a UK-only adviser will not raise.
It shrinks the credit pool. UK tax falls by £6,000, so creditable foreign tax falls by about $7,800. Daniel has a surplus, so nothing changes today — but credits expire after ten years, and a smaller pool is a smaller buffer for the year a bonus breaks the pattern.
It may not reduce US taxable income at all. A UK workplace pension is not a US-qualified plan. Whether contributions are excluded from US income, and whether growth inside the scheme is deferred, depends on the scheme type and on the treaty's pension articles — Article 18(1) on scheme income, Article 18(2) on contributions during cross-border employment. Neither is a blanket answer for a US citizen contributing to a UK scheme while UK resident, and the position needs a licensed sign-off rather than an assumption.
To see why the pool is worth guarding, add $10,000 of US-source bank interest: total income $153,000, taxable income $136,900, US tax before relief $25,454. The credit is limited by the share of taxable income that is foreign-source — about 93.5% — so it caps near $23,790 and roughly $1,664 of US tax is payable however much UK tax he has paid. No amount of UK tax reaches US-source income. That floor is where an aggressive pension contribution starts to cost real money, and where the 3.8% net investment income tax begins to bite once modified adjusted gross income passes $200,000 for a single filer.
Worked example 3 — a Briton in the US with UK rental income
Tom is a British national who has become a US tax resident and kept the flat in Manchester. Gross rents £24,000; agent fees, insurance and repairs £6,000; mortgage interest £7,000.
The UK side. As a British citizen he keeps the Personal Allowance while non-resident. Crucially, residential mortgage interest is not an expense: it is relieved as a basic-rate tax reduction.
| Line | Working | Amount |
|---|---|---|
| Gross rents | £24,000 | |
| Allowable expenses | (£6,000) | |
| Property profit | finance costs excluded | £18,000 |
| Personal Allowance | (£12,570) | |
| Taxable income | £5,430 | |
| Tax before the reduction | £5,430 × 20% | £1,086 |
| Finance-cost reduction | 20% of the lowest of £7,000 finance costs, £18,000 profit, £5,430 adjusted total income | (£1,086) |
| UK tax payable | nil | |
| Finance costs carried forward | £7,000 − £5,430 | £1,570 |
The unused portion carries forward — a UK-only asset with no US mirror. And unless HMRC has approved a form NRL1i application, his letting agent must deduct basic-rate tax before paying the rent over, so Tom suffers withholding on money he owes no UK tax on and reclaims it through the return.
The US side. The same flat goes on Schedule E, and the US measures profit differently in two large ways: mortgage interest is fully deductible, and depreciation is mandatory.
| Line | Working | Amount |
|---|---|---|
| Gross rents | £24,000 at $1.30 | $31,200 |
| Operating expenses | £6,000 | ($7,800) |
| Mortgage interest | deductible in full | ($9,100) |
| Depreciation on the building | assumed | ($9,000) |
| US taxable rental income | $5,300 | |
| Foreign tax credit | UK tax paid was nil | $0 |
| US tax at a 24% marginal rate | about $1,272 |
The depreciation line is an assumption, not a rate: it depends on the building's basis excluding land and on the recovery period. Property outside the United States must be depreciated under the Alternative Depreciation System, which runs longer than the domestic schedule, and the correct period for your placed-in-service date should be confirmed rather than guessed. You cannot decline it, and it reduces basis, so it returns as recapture on sale.
The point. Tom pays no UK tax, so he has no foreign tax credit, so the United States taxes the profit in full. This is the mirror of example 1 and the most useful idea on this page: relief in one country can destroy relief in the other. A UK allowance, reducer or exemption is not a saving for someone who also files a US return — it is a transfer of the liability across the Atlantic.
Three further items belong in his file, none of them on a UK-only return. Rental income is net investment income, so the 3.8% charge applies above the threshold, and while foreign income taxes cannot be credited against it, the Form 8960 instructions treat foreign income taxes allocable to investment income as a deduction in computing it. A sterling mortgage repaid or refinanced can generate a taxable exchange gain in dollars even where nothing changed in sterling. And on sale, a non-resident must report a disposal of UK land to HMRC within 60 days of completion even where there is no tax to pay, while the US gain is a separate dollar computation including depreciation recapture.
Reporting your foreign accounts and assets
Two separate reports catch most people, and they are not the same report.
The FBAR. A US person files FinCEN Form 114 where the aggregate value of foreign financial accounts "exceeded $10,000 at any time during the calendar year reported". It goes to the Treasury, not with your tax return, is due 15 April with an automatic extension to 15 October, and the IRS FBAR guidance confirms civil and criminal penalties are possible, with maximums adjusted annually for inflation. "Aggregate" is the word people miss: five UK accounts holding £2,500 each cross the line. For missed years, see our missed FBAR page.
Form 8938. A FATCA report filed with the 1040, covering a wider class of specified foreign financial assets. The IRS thresholds are far higher for people abroad: unmarried abroad, more than $200,000 on the last day of the year or $300,000 at any point during it; married filing jointly abroad, $400,000 and $600,000. Living in the United States the same tests are $50,000 and $75,000 unmarried, $100,000 and $150,000 jointly. Assets held outside an account with a financial institution go on the 8938 but not the FBAR.
ISAs and funds. A stocks-and-shares ISA is tax-free in the UK and fully visible to the IRS. Worse, most UK funds and investment trusts are passive foreign investment companies for US purposes: Form 8621 per holding, punitive default treatment under section 1291, and a qualified electing fund election that usually needs an annual information statement UK managers do not produce. See why the ISA wrapper does not cross the Atlantic.
Junior ISAs and Child Trust Funds. Almost nobody covers this, and it catches thoughtful parents. A Junior ISA takes £9,000 a year, the child controls it at 16 and can withdraw at 18, and a child cannot hold a Junior ISA and a Child Trust Fund at once. If the child is a US citizen, the account is the child's foreign asset, the underlying funds are very likely PFICs, and depending on structure there may be a foreign trust question on Form 3520. A £9,000 gift can quietly create an annual US filing obligation for a minor: see Junior ISAs for US citizen children.
National Insurance, Social Security and the Totalization Agreement
The income tax treaty does not cover social security contributions; a separate agreement decides which country's system you pay into. Under the US and UK totalization agreement, a worker sent temporarily by an employer from one country to the other normally stays in the sending country's system, provided the transfer is not expected to exceed five years, and the same applies to someone temporarily transferring their self-employment. The evidence is a certificate of coverage from the authority whose system you remain in.
The expensive surprise is self-employment. The IRS states the rules are "generally the same whether you are living in the United States or abroad", and that the exclusion does not reduce them: you count all self-employment income in net earnings "even if all, or a portion of, gross income was excluded because of the foreign earned income exclusion" — see the IRS guidance for self-employed people abroad. A US freelancer in London paying UK Class 2 and Class 4 National Insurance can therefore also face US self-employment tax on the same profit, unless a certificate of coverage is obtained and attached to the Form 1040 each year. Our guide to which country you pay social security to covers the paperwork.
The 2025 UK reforms, and why they can create a US bill
The UK replaced the remittance basis from 6 April 2025 with a residence-based system. For US citizens, two of the new reliefs can increase total tax.
The FIG regime. The four-year foreign income and gains regime lets a qualifying new resident claim relief on foreign income and gains arising in their first four years of UK residence. HMRC's helpsheet HS266 sets the conditions: one of your first four years of UK residence following at least ten consecutive tax years of non-UK residence, income arising on or after 6 April 2025, claimed each year on the SA109 pages. Claiming costs you your Personal Allowance and your capital gains annual exempt amount for that year.
Now apply it to a US citizen. The relief means no UK tax is paid on that income — and no UK tax paid means no foreign tax credit against the US liability on the same income. The US taxes it in full. A relief designed to attract people to the UK can convert a sheltered position into a plain US bill, while the lost allowance makes the UK side worse too. Whether to claim is a genuinely two-country calculation and the answer is often no: our note on the FIG regime for US citizens works through it.
The Temporary Repatriation Facility. Former remittance-basis users can designate pre-6 April 2025 foreign income and gains and pay a reduced charge. HMRC's manual gives 12% for amounts designated in a return for 2025-26 or 2026-27 and 15% for 2027-28, the facility runs for those three tax years only, and no further credit can be claimed against those rates. For a US citizen the difficulty is matching: the charge falls on capital designated rather than income arising that year, so there is frequently no corresponding US income item in the same year and credit category to set it against. Designating without modelling the US side is how people pay 12% in the UK and then pay again in the US. See the Temporary Repatriation Facility for US citizens.
Inheritance tax on a residence basis. From 6 April 2025 worldwide assets fall within UK inheritance tax where the individual is a long-term UK resident — resident in at least ten of the twenty tax years before the chargeable event, per HMRC's Inheritance Tax manual at IHTM47020. Leaving does not end it at once: someone resident between ten and thirteen years stays in scope for a minimum of three tax years, rising by a year for each further year of residence, to a maximum of ten. Because the US has its own estate tax and a separate estate and gift tax convention applies, both systems need modelling together.
State tax after you leave the US
Leaving the United States does not automatically end a state filing obligation, and this is the question a UK-based adviser structurally never thinks to ask.
Federal and state residence are decided separately. Several states, California and New York among them, apply a domicile test alongside a day-count test, and domicile persists until you both leave and show an intention not to return. A retained home, driving licence, voter registration, professional licence or business presence can all read as evidence you never really left — and a state does not care that you hold a UK residence certificate, because the treaty binds the federal government, not the states. Some states also tax income sourced there regardless of where you live, so a former resident with rental property or a business share keeps filing; others operate safe harbours for residents working abroad, valuable but precisely conditioned. The analysis has to be done against that state's own rules, at the time of the move. Our guide to state tax for US expats in California and New York covers the two hardest cases.
If you are behind, catching up without panic
Most people who have not filed were not evading tax; they did not know. There is a formal route for exactly that, and it is very different from quietly filing a few late returns.
The Streamlined Foreign Offshore Procedures are open to a US citizen or lawful permanent resident who, in one or more of the most recent three years, "did not have a U.S. abode and the individual was physically outside the United States for at least 330 full days". You file amended or delinquent returns for the most recent three years, delinquent FBARs for the most recent six, and a Form 14653 certifying non-willfulness — which the IRS defines as conduct "due to negligence, inadvertence, or mistake or conduct that is the result of a good faith misunderstanding of the requirements of the law". Where the IRS requirements are met in full, failure-to-file, failure-to-pay, accuracy-related, information return and FBAR penalties are not applied. You cannot use the programme once a civil examination has begun, which is why waiting for a letter is the worst plan available.
Know the alternatives. If the returns were right and only the FBARs are missing, the delinquent FBAR route may fit instead. If it is one late filing rather than years of non-reporting, ordinary penalty relief — reasonable cause, or the administrative first-time waiver — is a separate and simpler argument. A "quiet disclosure" gives up the penalty protection while reducing none of the risk. Our streamlined filing page sets out how a submission is assembled and reviewed.
What it costs, and how to choose a specialist
We do not publish fixed prices for cross-border work, because the fee tracks complexity rather than form count, and anyone quoting a flat figure before seeing your position is either guessing or excluding the slow part. What moves the number: how many returns (a US and a UK return are two engagements); investment complexity, since every UK fund holding is a potential Form 8621; pensions and equity awards, each needing a position on both sides; how many years, since a catch-up is not a current-year filing; rental property, businesses and trusts, each adding a computation in two currencies and two tax bases; and the quality of your records, which is the variable you control and the one that moves the fee most. We quote a fixed fee in writing after a scoping conversation. Our pricing page explains how scoping works.
Ten questions to ask before you hire
- Which licence covers my US return, and which covers my UK return? You want specifics: a licensed CPA or Enrolled Agent for the US filing, an ACCA-qualified accountant for the UK. A single credential covering both does not exist.
- Do you prepare both returns in-house or subcontract one side? Either works, but someone must own the consistency between them. Ask who, by name.
- Who signs, and will you register as my agent with both authorities? HMRC agent registration and authorisation to practise before the IRS are separate steps.
- Will the Form 1116 and the SA106 come from the same figures? The right answer is yes, with a reconciliation. Two spreadsheets produce two answers, and the mismatch surfaces years later.
- How will you choose between the credit and the exclusion for me? You want to hear about carryforwards, ten-year expiry, forfeited child and earned income credits, and the five-year lock-out after revoking. A one-line answer means a default, not a method.
- Do you handle PFICs in-house, and how many Forms 8621 have you filed? The most reliable competence filter in this field. Firms that avoid the work usually say so when asked directly.
- What exchange rate convention do you use, and is it documented? There should be a stated policy — yearly average for recurring items, spot for one-offs — applied consistently and recorded.
- What happens if HMRC and the IRS reach incompatible conclusions? A good answer names the treaty's mutual agreement procedure under Article 26 and is honest about how long it takes.
- Is the fee fixed, and what sits outside it? Ask what triggers a new fee: an extra 8621, an IRS notice, a state return, an amended prior year.
- Who reviews the work before it reaches me? On a cross-border return a second set of eyes is not a luxury. "The preparer checks it" is an answer.
Is it worth it? Not always. A US citizen abroad with one employment income, no investments outside a pension and accounts below the thresholds can carefully file a 1040 with a Form 1116. It changes the moment there is a second income source, a UK fund, a rental property, a company, a mid-year move or missed years, because a wrong position compounds annually and the fix always costs more than the advice. Our expat tax accountant page answers the narrower "who does my return" question.
Where to get free tax advice, and what it will not cover
A fair question with a straightforward answer. LITRG, the Low Incomes Tax Reform Group, publishes free and genuinely detailed UK guidance written by tax professionals. TaxAid and Tax Help for Older People advise people on low incomes who cannot afford a professional. HMRC and the IRS each answer their own rules free on their own helplines, and neither will advise on the other country's tax. In the US, IRS Free File offers free software below an income limit, and the VITA and TCE volunteer programmes prepare returns free for people on lower incomes, people with disabilities, limited-English speakers and those aged 60 and over, with services varying by site according to which volunteers are certified. The Taxpayer Advocate Service is an independent office inside the IRS for cases where normal channels have failed.
What none of them covers is the cross-border position. Free UK services are staffed for UK tax; volunteer US programmes are scoped for straightforward domestic returns, not Forms 2555, 1116, 8938 and 8621 read alongside a UK computation. Using them for the simple parts while paying for the interaction is a sensible strategy.
Who reviews and signs your filing
Every filing we prepare is signed off by a licensed human, and the licence matches the jurisdiction: a licensed CPA or Enrolled Agent reviews and signs the US filing, an ACCA-qualified accountant reviews and signs the UK filing. Agents prepare the workpapers, computations and sign-off memo; the licensed professional reviews the position; the client signs their own return. Nothing is submitted to the IRS or HMRC without a human review on the record. Where a position is genuinely uncertain — and in cross-border work some always are — we say so in writing rather than picking the convenient answer. To have that applied to your own position, book a consultation and bring last year's returns from both countries.