Self Assessment deadline 31 January 2027: every date for the 2025/26 tax year
If you were self-employed between 6 April 2025 and 5 April 2026, your online tax return and any tax you owe are due by 11:59pm on 31 January 2027. Here are the dates that matter and what to do now so January isn't a scramble.
On this page
Checked against GOV.UK on 23 October 2026. General information for sole traders in England, Wales and Northern Ireland, not tax advice. Scottish Income Tax rates are different.
The key dates for the 2025/26 tax year
| Date | What it is |
|---|---|
| 5 April 2026 | The 2025/26 tax year ended. It ran from 6 April 2025. |
| 5 October 2026 | Last day to register for Self Assessment if you haven't sent a return before. |
| 31 October 2026 | Deadline for a paper return (midnight). |
| 30 December 2026 | File online by then if you want a bill under £3,000 collected through your PAYE tax code (only if you also have a job or pension). |
| 31 January 2027 | Online return deadline, and payment deadline for the 2025/26 balancing payment and the first payment on account for 2026/27. |
| 31 July 2027 | Second payment on account for 2026/27, if you have to make them. |
HMRC must receive your return and any money you owe by the deadline. If you don't have final figures, you can file on time using provisional figures and correct them later.
If you registered after 5 October
HMRC gives you 3 months from the date on its letter to send the return, but the tax is still due by 31 January 2027. See how to register as a new sole trader.
What you pay on 31 January
For most self-employed people the 31 January payment has two parts: the balancing payment for 2025/26, and the first payment on account for 2026/27, usually half of the 2025/26 bill. The second part catches many people out in their first year. See payments on account explained.
To see your own figures, use the January tax bill calculator for the balancing payment and payments on account, or the self-employed tax calculator for a whole-year estimate.
What to do now
- Find your UTR and check you can sign in to your HMRC online account. See how to find your UTR.
- Add up your 2025/26 income from your invoices, and your CIS deductions from your monthly statements.
- Gather receipts and your mileage log. The records checklist lists what you need.
- File early if you can. You still pay by 31 January, but you know the figure in time to budget.
If you miss it
There's an automatic £100 penalty for a late return, even if no tax is due, plus separate penalties and interest for paying late. See late filing penalties and what to do if you missed the deadline.
This guide is part of our Self Assessment guides for the self-employed.
Free: The UK Contractor's Cheat Sheet 2026/27
CIS rates, overtime maths, tax dates, mileage, VAT and late payment, on 2 pages. Keep it on your phone or print it for the van.
Frequently asked questions
When is the Self Assessment deadline for 2025/26?
11:59pm on 31 January 2027 for an online return and for paying what you owe. Paper returns were due by 31 October 2026.
Is the deadline different if I registered late?
If you registered after 5 October 2026, HMRC gives you 3 months from its letter to file, but the tax is still due by 31 January 2027.
When is the second payment on account due?
31 July 2027, if you have to make payments on account for 2026/27.
Can I file before January?
Yes, any time from 6 April 2026. Filing early doesn't mean paying early.
Sources
- Self Assessment tax returns: deadlines – GOV.UK
- Self Assessment tax returns: sending a return – GOV.UK
- Understand your Self Assessment tax bill: payments on account – GOV.UK
- Self Assessment tax returns: penalties – GOV.UK
This guide is general information, not legal, tax or financial advice. Rules and rates change, so check the linked GOV.UK pages for the current position.