HMRC Formal Complaint Letter Template & Generator

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, plus a free tool to generate yours.

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 right to escalate to 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?
You can ask for it to be reviewed by a different officer, and ultimately refer the matter to the Adjudicator's Office, which independently reviews HMRC complaint handling.

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.

See our full letter template & generator library for related letters, or use our free checkers for guidance specific to your situation.