Self-Assessment Penalties: Avoiding the £900 Late Filing Fine
Chrissy Leach • 12 May 2025
If the 31 January deadline passed you by this year, it's not too late to act, and avoid mounting penalties.
What Happens If You Miss the Deadline?
2023/24 tax returns were due to be filed by 31 January 2025. HMRC's penalty system is designed to encourage timely filing. Here's what you can expect:
- Immediate £100 fine as soon as the 31 January deadline is missed.
- £10 per day for up to 90 days starting May 1, 2025 - that's an additional £900 if you still haven’t filed.
- Further penalties if your return is more than 6 or 12 months late, based on the tax owed.
Can You Appeal a Penalty?
Yes, but only in certain circumstances. Remember, it's Self-Assessment
- it's your responsibility to tell HMRC if you need to file a return, even if they've previously told you that you didn't need to, based on older information.
HMRC will consider appeals if you had a reasonable excuse such as:
- Serious illness
- Bereavement
- Unexpected delays (e.g. postal strikes, software failures)
You must appeal within 30 days of the penalty notice and provide supporting evidence.
What Should You Do Now?
- File your return as soon as possible. Even if you can’t pay your tax bill right away, filing stops further daily penalties.
- Pay what you can. You’ll reduce interest and might avoid further late payment penalties.
- Speak to an accountant. A professional can help you navigate penalties, appeal if needed, and arrange payment plans with HMRC.
To stay ahead of the game next year:
- Keep digital records year-round
- Use accounting software or outsource to a trusted accountant
- Set calendar reminders for key deadlines
At CJL Accountancy, we help individuals and small businesses stay compliant and penalty-free. If you’re unsure what to do next, get in touch for no-obligation support.
Need help with your tax return or penalties? Contact us today - we're here to help you get back on track.
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