How to appeal a Self Assessment late penalty

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.

Time limit

You usually have 30 days from the date on the penalty notice to appeal. If you're later than that, you'll need to explain why.

What may count as a reasonable excuse

• A partner or close relative died shortly before the deadline.
• An unexpected stay in hospital.
• A serious or life-threatening illness.
• Your computer or software failed while you were preparing your online return.
• Problems with HMRC's online services.
• A fire, flood or theft.
• Postal delays you couldn't have predicted.

You must send the return or payment as soon as possible after the problem ends.

What won't usually count

• Not having enough money to pay.
• Finding HMRC's online system too hard.
• Not getting a reminder from HMRC.
• Making a mistake on your return.
• Relying on someone else who let you down, unless you took reasonable care.

How to appeal

1. File the return or pay, if you haven't already.
2. Appeal online or by post using the details on the penalty notice, giving your UTR and the dates and reasons.
3. Include evidence, such as hospital letters or screenshots of errors.
4. If HMRC rejects the appeal, you can ask for a review or go to the tax tribunal.

Next time, get ahead with the records checklist, and see how penalties build.

This guide is part of our Self Assessment guides for the self-employed.