Free Template

Free HMRC Penalty Appeal Letter Template UK 2026

Use this free template to appeal an HMRC Self Assessment penalty. It covers late filing penalties (the most common type) and includes the key legal references you need. Copy the text, fill in your details, and send it to HMRC.

Late filing penalty appeal letter template

[Your Full Name]
[Your Address]
[Your Postcode]


HM Revenue & Customs
Self Assessment
PO Box 4000
Cardiff
CF14 8HR


[Date]


Re: Appeal Against Self Assessment Late Filing Penalty
Unique Taxpayer Reference (UTR): [Your UTR]
National Insurance Number: [Your NI Number]
Penalty Reference: [From your SA326D notice]
Tax Year: [e.g. 2024/25]
Penalty Amount: [e.g. GBP 100]


Dear Sir or Madam,


I am writing to formally appeal the above penalty issued under paragraph 3 of Schedule 55 to the Finance Act 2009 for the late filing of my Self Assessment tax return for the [tax year] tax year.


Reasonable Excuse

I submit that I had a reasonable excuse for the late filing of my return. The circumstances were as follows:


[Describe your situation in detail. Include specific dates, what happened, how it prevented you from filing, and any evidence you have. Be factual and specific. Examples:

  • I was admitted to hospital on [date] and was not discharged until [date], which was after the filing deadline.
  • My [close relative] passed away on [date] and I was dealing with funeral arrangements and the estate during the filing period.
  • My accounting records were destroyed by [fire/flood] on [date] and I was unable to reconstruct them before the deadline.
  • I experienced a serious illness ([condition]) from [date] to [date] which prevented me from attending to my tax affairs.
  • HMRC's online filing system was unavailable when I attempted to file on [date] and [date], as confirmed by HMRC's service status page.

]


Legal Basis

In accordance with paragraph 23 of Schedule 55 to the Finance Act 2009, a penalty does not arise where a person satisfies HMRC (or on appeal, the tribunal) that there is a reasonable excuse for the failure.


Applying the test established in Perrin v HMRC [2018] UKUT 156, I submit that:

  1. The circumstances described above constitute a reasonable excuse for failing to file on time.
  2. The excuse persisted throughout the period from the filing deadline until [date when excuse ended].
  3. Once the reasonable excuse ceased, I filed my return on [date] without unreasonable delay.

Supporting Evidence

I enclose the following documents in support of this appeal:

  • [Hospital discharge letter / GP letter / death certificate / insurance claim / etc.]
  • [Screenshots of HMRC system outage if applicable]
  • [Any other supporting documentation]

I therefore respectfully request that the penalty of GBP [amount] be cancelled in full.


If this appeal is unsuccessful, I wish to exercise my right to a statutory review under Section 49A(2) of the Taxes Management Act 1970, and I reserve my right to appeal to the First-tier Tribunal (Tax Chamber).


Yours faithfully,

[Your Name]

How to use this template effectively

  1. Be specific about dates. HMRC needs to see that your excuse covers the filing deadline period. Vague statements like "I was ill" without dates will be rejected.
  2. Attach evidence. A letter from your GP, hospital discharge papers, a death certificate, or screenshots of system outages significantly strengthen your appeal.
  3. Explain the gap. If there was a delay between your excuse ending and filing your return, explain why. The Perrin test requires that you acted without unreasonable delay once the excuse ceased.
  4. Send it by post or online. You can post this letter to the address above, or appeal online via your Personal Tax Account. The legal content is the same either way.
  5. Keep copies. Save a copy of everything you send. If HMRC rejects your appeal, you may need this for the statutory review or tribunal stage.

What HMRC does NOT accept as reasonable excuse

  • "I did not know I needed to file a return" — ignorance of the law is not a defence
  • "My accountant did not file on time" — you are responsible for your own return, not your accountant
  • "I could not afford to pay the tax" — inability to pay is not a filing excuse (but may apply to payment penalties)
  • "I was too busy" — HMRC does not accept this as reasonable
  • "I forgot" — not a reasonable excuse under the legislation

When a template is not enough

This template covers the standard late filing appeal. But HMRC penalties come in many forms: GBP 100 initial penalties, daily penalties (GBP 10/day after 3 months), 6-month penalties (5% of tax due or GBP 300, whichever is higher), and 12-month penalties. Each has different legislative references and different arguments that work.

TaxFlip analyses your specific penalty, identifies the strongest grounds, and generates a personalised appeal letter that cites the exact legislation for your situation. It takes 2 minutes and costs GBP 19.99 — less than the penalty itself.

Get a personalised appeal letter

This template shows the structure. TaxFlip writes the actual letter tailored to your specific penalty, excuse, and circumstances — citing the exact legislation, applying the Perrin test, and addressing your specific penalty type.

Generate My Appeal — GBP 19.99

Related guides

Frequently Asked Questions

Can I appeal an HMRC penalty myself without an accountant?

Yes. HMRC accepts penalty appeals directly from taxpayers. You do not need an accountant or tax adviser. A well-structured letter citing the correct legislation and explaining your reasonable excuse is the most effective approach. TaxFlip generates one automatically for GBP 19.99.

What counts as a reasonable excuse for HMRC?

HMRC recognises several categories of reasonable excuse: serious illness or hospitalisation, bereavement of a close relative, unexpected hospitalisation, fire/flood/theft affecting records, HMRC errors or delays, postal failures, and other genuine circumstances beyond your control. The legal test comes from Perrin v HMRC [2018] UKUT 156.

How long do I have to appeal an HMRC penalty?

You have 30 days from the date on your penalty notice (SA326D) to appeal. If you are past 30 days, you can still appeal but you must explain why the appeal is late. HMRC will consider late appeals if you have a good reason for the delay.

What is the difference between this free template and TaxFlip?

This template gives you the structure and general wording. TaxFlip analyses your specific penalty type, tax year, circumstances, and excuse, then generates a personalised letter that cites the exact legislation, applies the Perrin test to your situation, and addresses the specific penalty provisions. It takes 2 minutes and costs GBP 19.99.

Can I appeal a late payment penalty as well as a late filing penalty?

Yes. Late filing penalties fall under Schedule 55 of the Finance Act 2009, and late payment penalties fall under Schedule 56. Both can be appealed on the grounds of reasonable excuse. The template below is structured for late filing but can be adapted for late payment by changing the Schedule reference.