The deadline for submitting a UK Self Assessment tax return in paper format for the tax year 2024/25 is 31 October 2025. This deadline is crucial for individuals who need to file a paper return rather than an electronic one. The legal issue at hand concerns the requirements and implications of missing this deadline, including the penalties and practical consequences for taxpayers.
Key Points for Taxpayers to Remember
Paper Filing Deadline - For the 2024/25 tax year, the deadline for filing a paper Self Assessment tax return is 31 October
Calculation of Tax Liability - If you want HMRC to calculate your tax liability, you must submit your paper return by the 31 October deadline. After this date, you must either file online or calculate your liability yourself
Switch to Online Filing - If you miss the paper deadline, you can still file online by 31 January 2026. Electronic returns have a later deadline and provide more flexibility
Correct and Complete Return - All necessary information and accurate figures must be included. If you are unable to provide final figures, you may use the best estimate, but you must update HMRC as soon as accurate figures are available
Declaration - A paper tax return must include a signed declaration affirming that to the best of your knowledge, the return is complete and correct
Practical Advice and Common Pitfalls
Start Early - Begin gathering your information and completing your tax return well before the deadline to allow for postal delays or unforeseen issues
Supporting Documents - Ensure you retain all supporting evidence (receipts, records, etc.) in case HMRC requests them or if you need to amend your return later
Check Your Calculation - If you choose to calculate your own tax liability, check your computations carefully to avoid errors and penalties.
Amendments - If you realise after filing that you have made a mistake, notify HMRC as soon as possible to minimise penalties.
Consequences of Missing the 31 October Paper Filing Deadline:
Initial Penalty
An automatic penalty of £100 is imposed if your paper return is late, regardless of your tax liability or whether any tax is due.
Further Penalties for Continued Delay
If the return is more than 3 months late, further penalties apply:
3 to 6 months late - £10 per day for up to 90 days (maximum £900), in addition to the initial £100 penalty
6 to 12 months late - Additional penalty of the greater of 5% of the tax due or £300
Over 12 months late - Extra penalties apply, including up to 100% of the tax due in cases of deliberate and concealed withholding of information
Other Consequences
Interest on Late Payment:
Interest may accrue on overdue tax if your return is late and you have unpaid tax to settle
Loss of Right for HMRC to Calculate Liability:
If you miss the 31 October paper deadline, you must calculate your own tax liability or file online
Appeals and Reasonable Excuse:
It is possible to appeal a penalty if you have a reasonable excuse for missing the deadline, but HMRC applies strict criteria for what constitutes a reasonable excuse. Insufficiency of funds or reliance on another person does not generally qualify unless you took all reasonable care to avoid the failure
Table: Summary of Penalties for Missing the 31 October 2025 Paper Filing Deadline
|
How late? |
Penalty Amount |
Additional Notes |
|
Up to 3 months |
£100 |
Automatic, regardless of tax due |
|
3–6 months |
£10 per day (max £900) + £100 initial |
Daily penalty starts after 3 months |
|
6–12 months |
Greater of 5% of tax due or £300, plus all prior |
Cumulative with earlier penalties |
|
Over 12 months |
Up to 100% of tax due or £300, plus all prior |
Deliberate/concealed failures |
To conclude for the 2024/25 tax year, ensure your Self Assessment paper return is filed by 31 October 2025 to avoid an immediate £100 penalty. If you miss this, consider filing online by the later 31 January 2026 deadline. Prepare early, double-check your figures, and keep all supporting documents. Be aware that penalties escalate significantly the longer the delay, and HMRC is strict about what constitutes a reasonable excuse for late filing. Taking these steps will help you stay compliant and minimise the risk of costly penalties or further enquiries.
If you need any tax advice in Milton Keynes give a call to the team at Holmes Accountancy on 01908 315716 or contact us here.
The tax tip is provided for general guidance only; further advice should be sought, for specific issues.
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