REMEZ & PARTNERS

Appealing an HMRC penalty

You normally have 30 days from the date of the penalty notice to appeal, on the grounds of a reasonable excuse — something that prevented you complying despite taking reasonable care. File the outstanding return first: the penalty stops growing once it is filed, and an appeal made with the return still missing rarely succeeds.

Penalties are issued automatically, which means they are issued without knowing your circumstances. A good number of them are appealable — but the order of operations decides whether the appeal is worth making.

File first, appeal second

This order is not a formality. The £100 penalty is fixed, but what follows is not:£10 a day from 3 months late (up to 90 days — £900), then 5% of the tax due or £300, whichever is greater at six months, then another 5% or £300 at twelve.

Every week the return is outstanding, the amount you are appealing grows — and an appeal submitted while the obligation is still unmet asks HMRC to excuse something that is still happening.

What a reasonable excuse actually means

The test is whether something outside your control prevented you from complying, despite taking reasonable care to do so — and whether you put it right without unreasonable delay once the obstacle passed.

Generally accepted

  • Serious or life-threatening illness, yours or a close family member's
  • A bereavement shortly before the deadline
  • Fire, flood or theft that destroyed the records
  • A genuine failure of HMRC's online service, or postal delays outside your control
  • Unexpected hospital treatment
  • A disability or mental health condition that prevented compliance

Generally not

  • Not having the money to pay
  • Finding the online system confusing
  • An agent or bookkeeper who did not do what they promised — you remain responsible for your own return
  • Not receiving a reminder. HMRC does not have to send one
  • Being busy, or away

The line between the lists is control and care, not sympathy. A case that sounds unfair but shows neither rarely succeeds; a case that shows both usually does, even when it sounds mundane.

Get the return filed and the appeal made together

We file what is outstanding, then appeal on the strongest grounds the facts support — and where there is no reasonable excuse, we will tell you that rather than take a fee for an appeal that will fail.

Or send an email

Free assessment first. If there is work to do, you get a fixed quote in writing before anything starts.

Making the appeal

  1. File the return, if it is still outstanding.
  2. Appeal within 30 days of the notice, online or on the form HMRC provides.
  3. State the excuse and the dates — what happened, when it started, when it ended, and when you complied afterwards.
  4. Attach evidence. A letter from a hospital, a death certificate, a service status page. An unevidenced account is an assertion.
  5. If refused, ask for a review by an officer not previously involved, and then the tribunal if it comes to that.

If there is no excuse

Then the useful work is elsewhere: file, pay or arrange a payment plan, and stop the escalation. And fix the cause — most of the penalties we see come from the same January discovery repeating. See the deadlines, and the argument for filing in the spring.

Questions people ask

How long do I have to appeal?

Normally 30 days from the date of the penalty notice. Late appeals can be accepted where there is a good reason for the delay, but it is an extra argument you have to win before reaching the one that matters.

What counts as a reasonable excuse?

Something that stopped you meeting the obligation despite taking reasonable care: serious illness, a bereavement, a fire or flood, a genuine failure of HMRC's online service, unexpected hospital treatment. The test is whether a responsible person in your position could still have complied.

What does not count?

Not having the money, finding the system difficult, relying on someone else who let you down, or not receiving a reminder. Those are explanations rather than excuses, and appeals resting on them generally fail.

Do I have to file the return first?

Yes, in practice. The £100 penalty stops growing when the return lands — £10 a day accrues from 3 months late — and an appeal made while the return is still outstanding rarely succeeds.

Can I appeal a late payment penalty too?

The penalties, yes, on the same reasonable-excuse basis: 5% of the tax still unpaid at 30 days, again at 6 months, and again at 12 months. The interest, no — Interest runs from the due date regardless, and has no reasonable-excuse defence.

What if HMRC rejects the appeal?

You can ask for a review by an HMRC officer not previously involved, and beyond that appeal to the independent tax tribunal. Most cases end at the review stage, and a well-evidenced appeal is usually resolved before it gets that far.

Figures are for the tax year shown and change every April. They are general information, not advice — we check the current position for your circumstances before anything is filed.

Reviewed 19 October 2026.

Part of our work on hmrc letters and disclosures — if you want someone to take it off your hands, start with our what your HMRC letter means page.