Moving to—or living in—the UK need not feel like wrestling tax law. What helps is a clear decision path: are you a UK tax resident? If so, which of your incomes are taxed here? What reliefs and treaties reduce double taxation? And how do you hit filing deadlines without panicking? This guide gives you practical steps you can act on today: how to work out residency, what income to watch, which reliefs to claim, and the filing checklist you’ll use before 31 January.
ExpatsUK supports this guide with downloadable checklists, a residency decision tree and editable templates linked from this article. We also have community Q&A and, soon, a vetted adviser directory and local groups where members share real-world outcomes.
How to use this article: start with the Statutory Residence Test section (it changes everything). Then read the sections on taxable income and reliefs. Finish with the checklist and the short script for contacting an adviser if you need to.
Work out if you’re a UK tax resident — the Statutory Residence Test made simple
The Statutory Residence Test (SRT) is the legal route HMRC uses to decide residency for each tax year (6 April–5 April). Work through it in three steps: automatic overseas tests, automatic UK tests (the familiar 183‑day rule sits here), and, if neither applies, the sufficient‑ties test.
Three‑step roadmap
Step 1 — automatic overseas tests: you are automatically non‑resident if you meet certain strict conditions (for example, very few UK days in the year or full‑time work overseas with limited UK presence). Step 2 — automatic UK tests: you are automatically resident if, for example, you spend 183 days or more in the UK in the tax year, or have a UK home available and used under HMRC’s home test. Step 3 — if neither automatic test applies, the sufficient‑ties test looks at how many UK “ties” you have and how many days you spent here; the more ties, the fewer days needed to be considered resident.
Day counting rules and practical tips
A UK “day” is usually counted if you are in the UK at midnight. Exceptions exist for transit, exceptional circumstances (illness preventing travel), and some short transits through the UK. There’s also a “deeming” rule that can add prior‑year days in certain cases. Because these details matter, start a day‑count log today: use your phone calendar, keep boarding passes, and save travel itineraries. If you end up needing to explain days to HMRC, consistent contemporaneous evidence is the single most persuasive item you can produce.
The five ties — one sentence each
Family tie: you have a spouse/civil partner or minor child who is UK‑resident. Accommodation tie: a UK place is available to you for a period and you stay there for at least one night. Work tie: you do more than 40 UK work days in the tax year (3+ hours counts as a work day). 90‑day tie: you spent 90+ days in the UK in either of the two previous tax years. Country tie: the UK is the country where you spent the most days (used for people who are leavers).
Split‑year treatment demystified
Split‑year treatment applies when your residence status changes partway through a tax year. If it applies, the year is treated as two parts: a pre‑arrival/non‑resident part and a post‑arrival/resident part (or vice versa on departure). The practical effect is that only the resident portion of the year is taxed on worldwide income, which can make a big difference for employment income, pensions and gains. Common triggers are starting or ending full‑time work in the UK or overseas; check HMRC’s split‑year examples or use our residency decision tree to see if you qualify.
Quick decision examples
New arrival: Ana lived abroad for ten years, moved to the UK and spent 200 days in the tax year — she meets the 183‑day automatic UK test and is UK tax resident for that year. Long‑term commuter: Mark lives in Paris, has a UK flat and works in London for more than 40 UK work days — his work and accommodation ties increase the chance he’s resident under the sufficient‑ties test; log every UK day and check the decision tree. Departing family: Priya took a job overseas and left the UK in February; she may get split‑year treatment so only the pre‑departure period is taxed as UK resident — save employer letters and flight evidence to support the split‑year claim.
What evidence to keep
Start compiling: passport stamps and boarding passes, calendar screenshots or a day‑count spreadsheet, employer letters confirming dates and duties, tenancy agreements and council tax bills, utility bills, and bank statements showing residency patterns. Keep this evidence for at least the period HMRC can enquire into (see the Self Assessment section), and store it in a secure folder — digital copies are fine if dated and legible.
Which incomes the UK taxes — worldwide income, gains and common gotchas
The core rule: if you are UK tax resident you are generally taxed on worldwide income on an arising basis (that is, when it’s earned), and non‑residents are taxed on UK‑source income. That makes residency the first and most powerful decision.
“Income” covers employment pay (UK and overseas), self‑employment profits, rental income from UK or foreign properties, foreign interest and dividends, pensions, trust income and capital gains on assets. If it looks like the UK equivalent — tax usually follows the same category.
Important changes from 6 April 2025: the remittance basis is abolished for new claims and replaced by the Foreign Income and Gains (FIG) relief for qualifying new residents (four years of relief on many foreign incomes and gains). A Transitional Repatriation Facility (TRF) exists for pre‑2025 unremitted funds with reduced rates (commonly quoted 12–15% for specified periods) — check HMRC guidance for the precise treatment of your funds and read our guide to the end of the non‑dom regime in 2025 for practical steps.
Snapshot — headline 2025/26 numbers
| Item | 2025/26 (UK-wide unless noted) |
|---|---|
| Personal allowance | £12,570 |
| Basic rate | 20% on £12,571–£50,270 |
| Higher rate | 40% on £50,271–£125,140 |
| Additional rate | 45% on income over £125,140 |
| Dividend allowance | £500 (from April 2025) |
| Scotland | Uses different band structure and rates — check Scottish bands if resident in Scotland |
Common surprises: employer benefits paid overseas (think private medical, tuition reimbursements routed through an overseas payroll), foreign pensions, joint bank accounts (declarations may be needed), cryptocurrency disposals, and rental losses from foreign property. For each, check whether double tax relief, FIG relief, or local deductions apply — and keep the foreign tax receipt if you paid tax abroad.
Reliefs and treaties — avoiding double tax (credits, FIG relief and the UK‑US treaty)
The purpose of double taxation relief is simple: you should not pay tax twice on the same income. The two standard mechanisms are either a tax credit (where you get credit in the UK for foreign tax paid) or exemption (the foreign tax authority keeps the right to tax and the UK gives relief).
How the tax credit works — a worked example
Suppose you have foreign income of £10,000, taxed abroad at 15% (foreign tax £1,500). The UK tax on the same income at 20% would be £2,000. You can usually claim a foreign tax credit for the £1,500, so your UK top‑up is £500. You must keep foreign tax statements or official certificates to support the claim.
Tax treaties (DTAs) allocate taxing rights between countries and may set lower withholding rates for dividends, interest or royalties. Where a DTA exists, consult HMRC’s Double‑taxation digest or the treaty text to see which country has priority and whether the UK gives relief by credit or exemption. Practical step: if you will be subject to foreign withholding, get a certificate of UK tax residence from HMRC (or a local declaration) and send it to the foreign payer to reduce withholding where the treaty allows.
The FIG regime (from 6 April 2025)
FIG gives qualifying new UK residents relief for up to four tax years on many foreign incomes and gains, allowing remittance to the UK tax‑free during that window. Typical qualifiers are individuals who were non‑resident for at least ten of the previous ten tax years. FIG must be claimed on your Self Assessment and has exclusions (for example, certain employment income with UK duties). FIG claims also affect entitlement to the UK personal allowance and the capital gains tax annual exemption for the years claimed — read the rules before deciding.
Transitional Repatriation Facility (TRF)
The TRF is a temporary facility for funds that were unremitted before 6 April 2025 and allows a one‑off repatriation at a reduced tax charge (commonly 12–15% in the transitional windows). This is technical and time‑sensitive; check HMRC’s TRF guidance and consider specialist advice if you have material pre‑2025 unremitted funds.
Claiming relief on Self Assessment
Use the Foreign pages (SA106) to report foreign income and claim treaty relief or foreign tax credit. Enter each income type, the foreign tax paid, and attach (or retain) supporting documents. HMRC will normally ask for foreign tax certificates or official assessments. For US readers: the UK‑US treaty allocates taxing rights in several income categories; treaty relief is typically claimed on the UK return and may also affect your US filings — treat the treaty as a first step, then get country‑specific advice for complex situations. For a practical US‑focused checklist see our American expat 90‑day guide.
National Insurance for expats — when you pay and why it matters
National Insurance Contributions (NICs) are separate from income tax. They affect entitlement to the UK state pension and certain benefits. A few international assignment rules and social security agreements can mean you do not pay UK NICs while working in the UK for a short time.
| NIC item | 2025/26 figure |
|---|---|
| Primary Threshold / Lower Profits Limit | £12,570 pa |
| Upper Earnings / Profits Limit (UEL) | £50,270 pa |
| Employee Class 1 | 0% up to £12,570; 8% £12,571–£50,270; 2% above |
| Employer Class 1 | 0% up to £50,270; then 15% (with some reliefs) |
| Self‑employed | Class 2 £3.45/week (profits over £12,570); Class 4 9%/2% bands |
When expats don’t pay UK NICs: posted workers with a certificate of coverage (A1), people covered by social security agreements (for example the US Totalisation Agreement), or certain short international contracts. If you think you qualify for overseas coverage, request the certificate from your home authority (A1 or equivalent) and give it to payroll.
Voluntary NICs (Class 3) can fill gaps in your National Insurance record to protect future state pension entitlement. Check your NIC record online and consider voluntary payments if you have shortfall years.
Practical action: check your payslip for NI deductions, ask HR for a certificate of coverage if seconded out or in, and keep a simple NIC‑year log alongside your residency log.
Self Assessment and filing — register, deadlines, penalties and what to report
Who must register: people who are self‑employed, receive UK rental income, have untaxed foreign income or taxable capital gains, receive director’s pay, or otherwise have income not covered by PAYE. Non‑residents with UK taxable income often still need to file. If you think you must file, register for Self Assessment by 5 October following the tax year.
Key dates: register by 5 October; paper returns due 31 October; online returns due 31 January (11:59pm) after the tax year. Payments: 31 January is both the balancing payment and the first payment on account (where applicable); 31 July is the second payment on account.
Penalties: late online filing attracts an immediate £100 penalty; after three months daily penalties and higher fixed penalties apply; after six and 12 months the penalties rise and HMRC may charge increased penalties plus interest on late payments.
Forms you’ll use: SA100 is the main return. Use SA106 for foreign income and claims (double tax relief, FIG), SA103 for self‑employment, and SA105 for UK property. If you leave the UK permanently, file form P85 to tell HMRC and to claim any tax refund due.
Registering and filing from abroad: you still need to get a UTR and set up HMRC online services. You can register an agent to file on your behalf if you prefer. Keep digital copies of all foreign tax statements — HMRC will expect evidence for foreign tax credits or treaty claims.
Record keeping: generally retain tax records for at least five years after the 31 January submission deadline, but keep evidence for longer if it affects earlier years — in some circumstances HMRC enquiry periods extend many years. Keep invoices, payslips, bank statements, foreign tax receipts and travel evidence.
Capital gains, UK property and special cases that trip up expats
UK residents pay Capital Gains Tax (CGT) on worldwide gains; non‑residents are typically liable for CGT on disposals of UK residential property and certain other assets under non‑resident CGT rules. A key practical rule: if you sell UK residential property while non‑resident, you often must report and pay within a short window (HMRC’s non‑resident reporting/payment window has changed over time — check the current requirement early in the sales process).
Principal Private Residence (PPR) relief can exempt some or all of a sale if the property was your only or main home; moving abroad changes how much of the gain qualifies. Keep purchase and improvement records (invoices and receipts) because they form the cost basis and directly reduce your gain.
Short worked example (method): if you sell a buy‑to‑let for a gain of £50,000, first deduct allowable costs (purchase price, improvements) to get the taxable gain, then deduct the annual exempt amount (if available). The result is the taxable gain on which CGT rates are applied (rates depend on your remaining income tax band and whether the asset is residential). If you’re non‑resident, additional reporting windows and different relief availability may apply — begin the process early and seek specialist help for trusts or offshore company ownership.
Interaction with FIG and legacy remittance rules: if you previously relied on the remittance basis, the removal of that option for new claims from 2025 changes how repatriated funds are taxed and how gains are reported. If you have complex structures—trusts, offshore companies, or significant pre‑2025 funds—consider specialist advice and check TRF opportunities for a limited repatriation window.
Practical first‑year checklist — what to do in your first 30 days and first year
Immediate tasks (first 30 days): start a day‑count diary (phone calendar + a simple spreadsheet), collect travel evidence (boarding passes, tickets), ask your employer for a letter confirming start/end dates and duties, check whether you need a National Insurance number or a certificate of coverage, open a UK bank account if needed, and register for Self Assessment if you already know you will have taxable UK income.
First 3 months: gather overseas tax statements and foreign bank statements, check whether you may qualify for FIG relief and note which years you might claim, gather property purchase and improvement documents, download the UK‑country double taxation treaty text or a summary, and simplify record keeping for any self‑employment or rental income.
Before filing season: obtain your UTR and HMRC online access, prepare SA106 foreign pages (or instruct your adviser), secure foreign tax certificates, and set calendar reminders for 31 January. If you expect to pay tax, set up a direct debit for payments to avoid interest and penalties.
Printable checklist
- Start a day‑count diary (calendar + spreadsheet)
- Save passport stamps and boarding passes
- Keep tenancy agreements, council tax/utility bills
- Get employer letters confirming duties/dates
- Collect foreign tax certificates and statements
- Secure purchase/improvement invoices for property
- Register for Self Assessment and get your UTR
Useful templates (linked from ExpatsUK): a short email you can send to a tax adviser describing your situation, a one‑page residency factsheet you can print for your accountant, and a short HR request template to ask for proof of secondment or overseas duties. Use these templates to speed up your first adviser meeting. See our Moving to the UK from USA — A Calm, Practical Plan for a broader relocation checklist and practical moving tips.
When to call in a pro — what advisers do, typical costs and how ExpatsUK helps
Signals that you need professional advice: disputed residency status with HMRC, complex trusts or offshore structures, large unremitted funds, cross‑border pensions, a high‑value property sale, or exposure to multiple treaties and jurisdictions. These scenarios often require tailored legal and tax interpretation.
Who does what: chartered tax accountants prepare returns, calculate tax and claim reliefs; tax lawyers help with disputes and treaty interpretation; international payroll specialists help employers with NIC and PAYE questions. Ask for adviser credentials (CTA, Chartered Tax Adviser, or ACCA) and references from other expats where possible.
What to expect in your first meeting: a scoping conversation, a checklist of documents they need, an outline of the likely timeline and an initial fee estimate. Use this short script in your first email: “I arrived in the UK on [date]; previously non‑resident since [year]; my income types are [employment/pensions/rental/overseas investments]; I expect to file Self Assessment for tax year [year]. Please confirm availability and an estimate for an initial review.”
Ballpark costs: a simple UK Self Assessment return with no foreign complications can be modest, whereas cross‑border returns with treaty claims or FIG elections are more expensive. Fees vary by adviser and complexity — request a written engagement letter listing services and fees before work begins.
How ExpatsUK can help: use our downloadable residency decision tree and checklist to prepare for an adviser meeting, post an anonymised summary on our community boards to gauge peer experiences, and, when live, use our vetted adviser directory to find specialists who work with expats.
Conclusion — three practical next steps
Do these three things this week: 1) start a day‑count log and run the SRT decision tree to establish your residency position; 2) list all income types (UK and foreign) and assemble foreign tax receipts so you can claim credit or FIG where appropriate; 3) register for Self Assessment if needed, mark 31 January in your calendar and use the ExpatsUK checklist to prepare your return or a tidy brief for an adviser.
If you’ve got a complex situation—trusts, large repatriations, residency disputes—book a short call with a specialist and use the ExpatsUK templates to make that meeting productive. And if you’re unsure: post an anonymised summary on our community boards to see how others in your city handled similar cases before spending on formal advice.