Self-assessment key dates
Failure to notify chargeability to tax, or pay any tax due on time may result in penalties. Key dates to be aware of over the next year are outlined below. Note how penalties increase with the lateness of the return.
31 January 2026
Deadline for filing 2024/25 online returns and certain claims and elections.
A £100 penalty will arise if your return is not filed by 31 January, regardless of whether any tax is due.
A £100 penalty per partner applies for a late partnership return.
Paper returns for 2024/25 not filed by this date will be three months late and may attract a daily penalty of £10 a day, for up to 90 days thereafter.
The balance of your 2024/25 tax liability, together with the first payment on account for 2025/26, is due.
3 March 2026
The first automatic 5% late payment penalty will apply to any outstanding 2024/25 tax.
5 April 2026
The four-year time limit for certain claims and elections in respect of the 2021/22 tax year expires.
30 April 2026
Paper returns for 2024/25 not received by this date will now be six months late, so a further penalty may be charged of 5% of any tax due, or £300 if greater.
Online tax returns for 2024/25 not filed by this date will be three months late and exposed to daily penalties of £10 a day for up to 90 days, to a maximum total of £900.
31 July 2026
Due date for the second payment on account for 2025/26.
Online returns for 2024/25 not filed by this date will now be six months late and a further penalty may be charged of 5% of the tax due, or £300 if greater.
1 August 2026
The second automatic 5% late payment penalty will apply to any outstanding 2024/25 tax.
5 October 2026
Deadline to notify HMRC of your chargeability to tax if you have not been issued with a return (or a notice to file a return) and you have an income tax or CGT liability for 2025/26.
31 October 2026
Deadline for submitting 2025/26 paper returns.
For paper returns filed by this date, HMRC should be able to:
– Calculate your tax for you;
– Tell you what you owe by 31 January 2027; and
– Collect tax through your tax code, where you owe less than £3,000.
If your paper return is submitted after this date, you will be charged an automatic £100 penalty.
Paper returns for 2024/25 not submitted by this date will now be 12 months late and subject to a further penalty of 5% of the tax due, or £300 if greater.
30 December 2026
Deadline for online filing for 2025/26 if you want HMRC to collect tax through your tax code (where you owe less than £3,000).
31 January 2027
Filing deadline for 2025/26 online returns.
Payment date for balancing tax payment in respect of 2025/26 and first payment on account for 2026/27.
Time-To-Pay arrangement (TTP)
If you are struggling to pay your tax on time, you should be able to set up a TTP before the tax falls due. This will allow you to pay the tax by instalments and avoid penalties.
Please contact us if you need to set up a TTP – we can help!
