Thousands of immigrants in the UK overpay income tax every year — often because they started a job part-way through the tax year, paid emergency tax on their first payslip, or left the UK before the year ended. HMRC will sometimes issue a refund automatically, but often you have to claim it yourself.
How do you know if you are owed a refund?
You may have overpaid tax if you: started work mid-way through the tax year (April–March); were put on an emergency tax code (W1, M1, or BR) by your employer; had multiple jobs in the same year; left the UK before 5 April; had income below the Personal Allowance (£12,570 for 2025/26). HMRC will send a P800 letter if they calculate you are due a refund — but this does not always happen automatically.
Method 1 — P800 letter from HMRC (automatic)
After the tax year ends (5 April), HMRC reviews your records and sends a P800 if they think you overpaid. If you receive one, you can claim online at tax.service.gov.uk using your Government Gateway login. Refunds via bank transfer usually arrive within 5 working days. If you do not claim online within 45 days, HMRC will send a cheque.
Method 2 — Claim a repayment yourself via HMRC online
If you have not received a P800 but think you overpaid, log into your Personal Tax Account at gov.uk/personal-tax-account and request a repayment directly. You will need your National Insurance number, Government Gateway login, and bank details.
Method 3 — P85 form (leaving the UK)
If you are leaving the UK permanently or for a long time, fill in the P85 form (available on gov.uk) to claim back overpaid tax for the part of the year you were not in the UK. Attach your P45 (issued by your last employer). Refunds can take 6–12 weeks.
Self Assessment — do you need to file a tax return?
Most employees in the UK do not need to file a Self Assessment tax return — tax is deducted automatically through PAYE. However, you must file Self Assessment if you: earned more than £100,000; had income from self-employment of more than £1,000; received untaxed income (rental, dividends, overseas income); or were a company director. Register at gov.uk/log-in-file-self-assessment-tax-return.
💡 Tip
Keep your P60 (given by your employer at the end of each tax year in April) and P45 (given when you leave a job). These are your proof of income and tax paid — you will need them for any tax repayment claim.
What about National Insurance?
NI overpayments are less common but can happen if you had multiple jobs that together pushed you over the NI earnings threshold. If you paid too much NI, HMRC usually refunds it automatically after the tax year — or you can contact the NI helpline on 0300 200 3500.
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