Online returns for 2025-26 are due by 11:59pm on 31 January 2027, and the tax you owe must be paid by 11:59pm on 31 January 2027. Here’s who has to file, what you’ll owe on the day, what it costs to be late, and what to gather first.
Filing for 31 January 2027? Our one-off tax return isn’t open yet: tax plans start once our HMRC registrations are complete. Don’t wait for us to meet this deadline. You can file online with HMRC yourself.
| Date | What happens |
|---|---|
| 5 October 2026(passed) | Tell HMRC you need to send a 2025-26 return (first-timers) |
| 31 October 2026 | Paper returns must reach HMRC |
| 30 December 2026 | File online by this date to have what you owe collected through your tax code, if you owe less than £3,000 and already pay tax through PAYE (a job or a company pension) |
| 31 January 2027 | Online returns must be sent |
| 31 January 2027 | Pay what you owe for 2025-26, and your first payment on account for 2026-27 if one applies |
| 31 July 2027 | Second payment on account for 2026-27, if payments on account apply |
Registered after 5 October? If you register after 5 October 2026, HMRC will send a letter or email with a different deadline for the 2025-26 return, 3 months from the date on it; the tax must still be paid by 11:59pm on 31 January 2027.
You must send a tax return for the last tax year (6 April to 5 April) if, among other reasons, you were self-employed as a sole trader and earned more than £1,000 before taking off anything you can claim tax relief on, or you were a partner in a business partnership. You may also need to send one if you had untaxed income, such as money from renting out property, tips and commission, savings interest, dividends or foreign income.
CIS subcontractors: CIS deductions are payments towards your tax, not the end of it. Your tax return works out what you really owe and sets your deductions against it. Over-deducted CIS is claimed back through your tax return. The sooner after 5 April you file, the sooner HMRC can repay you. Estimate your CIS refund.
Two payments on account, each usually half of last year's bill, are due by 31 January and 31 July unless last year's bill was under £1,000 or more than 80% was collected at source.
Payments on account are payments towards the next tax bill and include Class 4 National Insurance for the self-employed; each is half of the tax owed the previous year. They are not needed if last year's bill was under £1,000 or more than 80% of the tax owed was paid outside Self Assessment.
If payments on account apply, the amount due by 31 January is any balancing payment for the tax year just ended plus the first payment on account towards the next bill, which is usually half of the tax owed for the year just ended.
Your 2025-26 bill is £4,000, and you made no payments on account towards it. As the bill is over £1,000, payments on account apply (unless more than 80% of your tax was paid at source). By 31 January 2027 you pay £4,000 for 2025-26 plus a first payment on account of £2,000 for 2026-27: £6,000 in all. The second £2,000 is due by 31 July 2027.
An illustration of the rule above, with a made-up bill. Your own payments on account are shown in your HMRC online account.
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No payment is taken while you wait. You’ll be able to save a card when the waitlist opens for sign-up, and nothing is charged until your service starts.
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We’ll email you when the service opens, with a link to set up your account. No payment is taken. If your return is due on 31 January, don’t wait for us: file it online with HMRC.
Online returns for 2025-26 are due by 11:59pm on 31 January 2027, and the tax you owe must be paid by 11:59pm on 31 January 2027. Paper returns must reach HMRC by 31 October 2026.
If you are a sole trader who earned more than £1,000 before expenses, or a partner, yes. CIS deductions are payments towards your tax, not the end of it. Your tax return works out what you really owe and sets your deductions against it. Over-deducted CIS is claimed back through your tax return. The sooner after 5 April you file, the sooner HMRC can repay you.
A late SA return gets £100 at once, £10 a day after 3 months (up to £900), then the higher of 5% of tax due or £300 at 6 months and again at 12 months. Under the current SA rules, late payment penalties are 5% of tax unpaid at 30 days, 6 months and 12 months, plus interest.
If payments on account apply, the amount due by 31 January is any balancing payment for the tax year just ended plus the first payment on account towards the next bill, which is usually half of the tax owed for the year just ended. Payments on account are payments towards the next tax bill and include Class 4 National Insurance for the self-employed; each is half of the tax owed the previous year. They are not needed if last year's bill was under £1,000 or more than 80% of the tax owed was paid outside Self Assessment.
If you cannot pay your tax bill in full, you may be able to set up a payment plan with HMRC to pay it in instalments. HMRC checks whether the plan is affordable; if one cannot be agreed, they ask for the full amount. Send your return on time anyway: the late filing penalty is separate from the late payment one.
If you register after 5 October 2026, HMRC will send a letter or email with a different deadline for the 2025-26 return, 3 months from the date on it; the tax must still be paid by 11:59pm on 31 January 2027.
This is general information to help you understand the rules. It isn't tailored to your circumstances, so check your own position before acting on it.