Self Assessment deadline 31 January 2027: what to do now

If you are self-employed, a landlord or a company director with income outside PAYE, your 2025 to 2026 tax return is due online by **11:59pm on 31 January 2027**. Any tax you owe for that year is due on the same day. Starting in October rather than January means fewer surprises, time to plan the payment and no last-minute scramble for paperwork.

If you register after 5 October, HMRC gives you a later deadline for the return itself, three months from the date of its letter, but the tax is still due by 31 January. GOV.UK has the [full list of deadlines](https://www.gov.uk/self-assessment-tax-returns/deadlines), including who can pay through their tax code.

Most people taxed only through PAYE do not. You usually need to file if you are self-employed, a partner in a partnership, receive rental income, have untaxed income such as larger dividends or savings interest, or HMRC has written asking you to. HMRC's [tax return checker](https://www.gov.uk/check-if-you-need-tax-return) gives a definite answer for your situation.

- **Income:** sales or turnover records if you are self-employed, rent received if you are a landlord, P60s or P45s, dividend vouchers, and bank or savings interest. - **Expenses:** receipts and records of business costs, letting costs and mortgage interest statements for rental property. - **Pension contributions and Gift Aid donations**, which can reduce your tax. - **Your Unique Taxpayer Reference (UTR)** and your Government Gateway sign-in details. - **Last year's return**, so you can check for anything you have forgotten.

If your last Self Assessment bill was £1,000 or more, HMRC normally asks for two advance payments towards next year's tax, each half of last year's bill. They are due on 31 January and 31 July. You do not have to make them if last year's bill was under £1,000, or if more than 80% of your tax was already collected another way, such as through PAYE.

This is why a first-year bill can feel so large. In January you may pay the full tax for the year just gone **and** the first payment on account for the current year. If your income has fallen, you can ask HMRC to reduce your payments on account. See [how payments on account work](https://www.gov.uk/understand-self-assessment-bill/payments-on-account).

HMRC charges an initial £100 penalty if your return is late, even if you have no tax to pay. After three months, £10 a day is added, up to £900. Further penalties apply at six and twelve months, and late payment brings its own penalties of 5% of the unpaid tax at 30 days, six months and twelve months, plus interest. GOV.UK sets out the [penalties in full](https://www.gov.uk/self-assessment-tax-returns/penalties).

If you are already late, file as soon as you can. The penalties grow the longer it is left.

From April 2026, sole traders and landlords with qualifying income over £50,000 have been keeping digital records and sending quarterly updates. The threshold falls to £30,000 from April 2027 and £20,000 from April 2028. If you are near those levels, read our [Making Tax Digital for Income Tax guide](/making-tax-digital-income-tax) so next year's return is not a shock.

We prepare and file Self Assessment returns for directors, sole traders, partners and landlords, check that reliefs and allowances are claimed, and tell you what is due and when well before the deadline. Our [accounts and tax service](/accounts-and-tax) covers Self Assessment alongside company accounts, and our [bookkeeping service](/bookkeeping) keeps records up to date through the year. If you are changing accountant, read [how switching accountants works](/switching-accountants). *Last reviewed October 2026. Dates and penalties checked against GOV.UK on 7 October 2026. This guide is general information, not advice for your specific circumstances.*