Self Assessment deadlines
Every key date for your tax return, a countdown to the next one, and a calculator to check whether you need to make payments on account.
Next deadline
– days
Your personal tax dates
Key dates
| Deadline | What's due |
|---|
All deadlines are 11:59pm on the day. If you register after 5 October, HMRC gives you 3 months from your registration to file, but the payment deadline doesn't move.
General information based on GOV.UK guidance checked on 11 October 2026. Not tax advice. Check your own position in your HMRC online account.
Payments on account, explained
If your last Self Assessment bill was £1,000 or more, HMRC usually asks you to pay towards next year's bill in advance, in two instalments called payments on account. Each one is half of last year's bill.
- 31 January: first payment on account for the current tax year (on top of any balance you owe for last year)
- 31 July: second payment on account
- The following 31 January: a balancing payment if you owe more than you've paid
You don't need to make them if last year's bill was under £1,000, or if more than 80% of all the tax you owed was taken at source (for example through PAYE). If you expect a lower bill this year, you can ask HMRC to reduce them, but you'll pay interest if you reduce them too far.
Penalties for missing a deadline
| How late | Late filing penalty |
|---|---|
| 1 day | £100 |
| 3 months | £10 a day, up to £900 |
| 6 months | A further 5% of the tax due or £300, whichever is more |
| 12 months | Another 5% or £300, whichever is more |
Paying late is separate: you're charged interest, plus 5% of the unpaid tax at 30 days, 6 months and 12 months late. If you've joined Making Tax Digital, HMRC's newer points-based penalty system applies instead.
Frequently asked questions
When is the Self Assessment deadline?
For online returns, 11:59pm on 31 January after the tax year ends. That's also when you must pay what you owe. Paper returns are due earlier, by 31 October.
Do I need to file a tax return?
Usually yes if you're self-employed and earned more than £1,000, have rental income, or have other untaxed income. Use GOV.UK's checker to be sure.
What's the 30 December deadline?
If you owe less than £3,000 and get PAYE income, HMRC can collect what you owe through your tax code over the next year instead of a lump sum. To do that, you must file online by 30 December.
I missed the deadline. What should I do?
File as soon as you can. The £100 penalty applies straight away, but daily penalties only start after 3 months, so the sooner the better. If you had a genuine reason, such as serious illness, you can appeal.
Is Self Assessment being replaced by Making Tax Digital?
For sole traders and landlords over the income threshold, yes. They send quarterly updates and file their return through MTD software, though the 31 January deadline stays. Check if and when it applies to you.
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