HMRC Formal Complaint Letter: Free Template and What to Include

If you need to make a formal complaint about HMRC handling of your tax affairs, a written letter is the recommended first step — it creates a clear record and shows you're pursuing the matter formally. Below is what a strong hmrc formal complaint letter should include.

What this letter needs to cover

• Describe the issue chronologically with reference numbers and dates of contact
• State specifically what went wrong
• State the impact (financial loss, stress, time)
• Request a full investigation, written response within 30 days, and appropriate remedy
• Note the next steps: HMRC's first and second review, then the Adjudicator's Office

When a formal HMRC complaint is the right route

If HMRC has made an error, caused unreasonable delay, or you believe you've been treated unfairly, a formal complaint through their dedicated complaints process is different from an ordinary query or dispute about a tax decision — it's specifically about how you were treated or how a mistake occurred, and can include a claim for financial redress if their error caused you genuine loss.

What to include before you send it

• A clear, factual timeline of what happened and where you believe HMRC went wrong
• Reference numbers for the specific tax matter involved
• Any direct financial loss or additional cost you've incurred as a result
• What outcome you're seeking — correction, an apology, or compensation for genuine loss

What HMRC can actually offer in redress

Where HMRC accepts they've made an error causing genuine financial loss, they can offer compensation for reasonable costs incurred as a direct result — such as professional fees needed to resolve the issue — though this isn't automatic and needs to be clearly evidenced in your complaint.

Frequently Asked Questions

What if I'm not satisfied with HMRC's response to my complaint?
Ask HMRC for a first review of your complaint, then a second review if you disagree with the outcome. If you are still unhappy, the Adjudicator's Office can normally accept your complaint up to 6 months after you receive HMRC's second review.

Is this the same as appealing a tax decision?
No — a complaint is about how you were treated or an administrative error, while appealing a specific tax decision (like a penalty) generally follows a different, formal appeals process.

[Your Name]
[Your Address]
[Your Postcode]
[Your Telephone Number]
[Your National Insurance Number]
[Your Unique Taxpayer Reference (UTR), if you have one]
HM Revenue and Customs
[The address on your HMRC letters]
[Date]

Dear Sir / Madam,

Subject: Formal complaint about HMRC's service – [your reference number, if any]

I am writing to make a formal complaint about the service I have received from HM Revenue and Customs about my [tax type, e.g. Self Assessment / PAYE / Child Benefit] for the tax year [e.g. 2024/25].

What happened, in date order:
• [Date] – [e.g. I asked for a tax refund (reference [number])]
• [Date] – [e.g. An adviser on the phone told me [what], which was wrong]
• [Date] – [e.g. I wrote to you again and had no reply]

What went wrong: [e.g. unreasonable delay / wrong advice / no response].

This has caused me [e.g. financial loss of £[amount] / stress / time spent chasing - say which].

Please investigate this complaint fully and send me a written response within 30 days. I ask you to [e.g. deal with my original request, correct my records, apologise, and pay compensation for my costs, the delay and the worry caused].

If I am not satisfied with your response, I will ask for a second review, and then contact the Adjudicator's Office.

Yours sincerely,

[Your Signature]
[Your Printed Name]