How to appeal an HMRC penalty

The 30-day deadline

You usually have 30 days from the date of the penalty notice to appeal. Late appeals are accepted only in exceptional circumstances, so move quickly.

Grounds for appeal

You can appeal if you have a reasonable excuse — circumstances that genuinely prevented you from meeting your obligation. Examples HMRC has historically accepted:

• Serious illness or hospitalisation
• Bereavement of a close family member
• HMRC system outages on the deadline
• Postal disruption that prevented receiving correspondence
• Theft, fire, or flood that destroyed your records
• An issue with your software you couldn't have anticipated

The reasonable excuse must have continued throughout the period of failure, and you must have acted to fix things as soon as the excuse no longer applied.

What is NOT a reasonable excuse

• "I forgot"
• "I was too busy"
• "I thought my accountant was doing it"
• "I couldn't afford the tax"
• "My system crashed and I didn't try again"
• Misunderstanding the rules (with a few narrow exceptions)

How to appeal

1. Read the penalty notice carefully and identify the deadline
2. Gather evidence supporting your reasonable excuse
3. Appeal in writing within 30 days — by post, online via Government Gateway, or for some penalties through the appeal form
4. State clearly which penalty you're appealing, the grounds, and provide evidence
5. If HMRC rejects your appeal, you can request a review or escalate to the First-tier Tax Tribunal

What to write

Be specific and factual. Include:

• Your reference (UTR, NI number, or company number)
• The exact penalty being appealed (date and amount)
• The reason for the failure
• Evidence (medical certificates, system error screenshots, etc.)
• Confirmation that you've now done what was needed (filed, paid, etc.)