How to file your income tax return in the United Kingdom
Filing your income tax return in the United Kingdom: who must file, the tax year and deadline, what documents you need, and what happens if you are late.
Self-employed people with turnover over £1,000, landlords, higher earners with untaxed income, and anyone HMRC sends a notice to file. Most employees on PAYE alone do not file.
Tax year and deadline
Tax year 6 April to 5 April. Paper returns by 31 October; online returns and the balancing payment by 31 January; payments on account on 31 January and 31 July.
Filing step by step
Sign in to your HMRC account with your Government Gateway ID and UTR.
Work through the employment, self-employment and other income pages using your P60, P11D, invoices and bank records.
Claim allowable expenses and pension or Gift Aid relief.
Submit, note the calculation, and pay by 31 January.
Penalties for filing or paying late
A late Self Assessment return costs an initial £100 penalty. After three months HMRC adds daily penalties of £10 a day up to a maximum of £900. After six months there is a further penalty of 5% of the tax due or £300, whichever is greater, and another 5% or £300 charge at twelve months. Tax paid late attracts penalties of 5% of the unpaid tax at 30 days, six months and twelve months, plus interest on the amount owed. Penalties must be paid within 30 days of the notice date, and a reasonable excuse can be appealed.
Written from published tax-authority guidance and reviewed on 2026-10-11. Everything here is indicative rather than a ruling on your circumstances, and rules change. Confirm anything you rely on with HM Revenue and Customs (HMRC) before acting on it, and tell us if you find something out of date so we can correct it.
This guide explains the rules in general terms and is not tax advice for your circumstances. Confirm your position with a qualified adviser or with HM Revenue and Customs (HMRC).