HMRC Complaint & Claim Letter Generator

The generator above builds a formal letter to HMRC for you in seconds - pick what it is for, add your details, and download, copy or print it. This guide explains how to complain to HMRC effectively: when a complaint is the right step, what to put in your letter, how long HMRC takes to respond, and how to escalate if you are not satisfied. Everything you type stays in your browser; nothing is sent to us.

When to complain to HMRC

A formal complaint is the right route when HMRC has made a mistake, given you poor service, caused unreasonable delays, or treated you unfairly. Common reasons include errors in your tax or tax code, a refund that has not arrived, repeated mistakes, long waits for a response, or being given wrong information that cost you money. If you simply disagree with a tax decision, that is usually an appeal rather than a complaint - but if the problem is how you were treated, a complaint is appropriate.

What to include in your letter

A good complaint letter is clear, factual and specific. Include:

• Your full name, address, and any reference numbers - your National Insurance number and Unique Taxpayer Reference (UTR) where relevant.
• A clear heading showing it is a formal complaint.
• What happened, in date order, with the facts and any reference numbers for letters or calls.
• What went wrong and the impact it had on you.
• Exactly what you want HMRC to do - correct the error, pay the refund, apologise, or explain.
• A request that they confirm receipt and respond in writing within their published timescales.

Keep it polite and concise. Stick to facts rather than emotion, and keep a copy of everything you send along with the date you sent it.

The types of letter this tool creates

• Complaint to HMRC - for delays, errors or poor service.
• Tax refund request - when you believe you have overpaid tax.
• Incorrect tax code query - to get a wrong code corrected and any overpaid tax back.
• Council Tax band challenge - to ask the Valuation Office (or Scottish Assessor) to review your band.
• Chasing a late refund - when a refund you were promised has not arrived.

How the HMRC complaints process works

HMRC handles complaints in stages. Your first complaint is dealt with by the relevant department (tier 1). If you are not happy with the outcome, you can ask for it to be looked at again by a different officer (tier 2). If you remain dissatisfied after both tiers, you can take your complaint to the independent Adjudicator's Office, and ultimately to the Parliamentary and Health Service Ombudsman through your MP. Most issues are resolved well before that, but knowing the escalation path helps if you hit a wall.

How long HMRC takes to respond

HMRC works to published response timescales and aims to acknowledge and respond to complaints within a set period, though busy periods can cause delays. If you do not hear back within a reasonable time, it is fair to chase and to reference your original letter and its date. Keeping a clear paper trail - copies, dates, and reference numbers - makes chasing far easier and strengthens your position if you need to escalate.

Can you claim compensation?

If HMRC's mistakes or delays have caused you actual financial loss - for example costs you would not otherwise have incurred - you can ask them to consider reimbursing reasonable costs, and sometimes a small payment for worry and distress in serious cases. Be specific about what the error cost you and include evidence. The Adjudicator can also recommend redress if HMRC does not put things right.

Before you send it

Always confirm the correct postal address on GOV.UK before posting, as HMRC addresses change and differ by tax. Keep a copy of your letter and note the date. For Council Tax band challenges in England and Wales, the body is the Valuation Office Agency; in Scotland it is your local Assessor.

A simple structure for your letter

If you prefer to write your own letter rather than use the generator, a clear structure works best. Start with your address and the date, then HMRC's address and your references (National Insurance number and UTR). Open with a short line stating it is a formal complaint and what it concerns. Use the first paragraph to set out the facts in date order. Use the second to explain what went wrong and how it affected you. Use the third to state plainly what you want HMRC to do and by when, and to ask them to confirm receipt and respond in writing. Close politely and sign it. Keeping each section short and factual makes your complaint easy to act on and hard to dismiss.

Tax code complaints in detail

One of the most common reasons to contact HMRC is an incorrect tax code, which can mean you are paying too much or too little tax through PAYE. If your code looks wrong - for example because a benefit you no longer receive is still being deducted, or you have been put on an emergency code after changing jobs - set out your current code, why you believe it is wrong, and what you think it should be. Ask HMRC to correct it, to refund any tax overpaid as a result, and to confirm the corrected code to both you and your employer. Because a wrong code repeats every payday, getting it fixed quickly stops the problem compounding across the year.

Common mistakes when complaining

A few avoidable mistakes weaken otherwise valid complaints. Writing emotionally rather than factually makes it easier for HMRC to focus on tone instead of substance. Leaving out reference numbers slows everything down. Not keeping copies means you cannot prove what you sent or when. Sending the letter to the wrong address - HMRC uses different addresses for different taxes - can delay a response by weeks. And giving up after the first reply means many people never reach the second tier or the Adjudicator, where persistent, well-documented complaints are often resolved. Staying calm, specific and organised is what gets results.

How to escalate if HMRC does not put it right

If your first complaint does not resolve the issue, you have a clear escalation path. The first step is to ask HMRC to review it again under their second tier, where a different officer takes a fresh look. If you are still not satisfied after that, you can take your case to the independent Adjudicator's Office, which examines complaints about how HMRC has handled matters and can recommend that things be put right, including reasonable costs and, in some cases, a payment for poor service. Beyond that, you can ask your MP to refer the complaint to the Parliamentary and Health Service Ombudsman. Each stage expects you to have gone through the previous one, so keep every reply HMRC sends, as the Adjudicator will want to see the full history. Most complaints are resolved long before this point, but knowing the route gives you leverage and reassurance.

Keep records and follow up

Whatever your complaint is about, good record-keeping is what turns a grievance into a result. Keep a copy of every letter you send and receive, note the dates of phone calls and the names of anyone you speak to, and save reference numbers in one place. If HMRC does not respond within a reasonable time, send a polite follow-up that refers back to your original letter and its date, and state that you expect a reply. A calm, well-documented paper trail makes it far harder for a complaint to be lost or ignored, and it is exactly the evidence you will need if you decide to escalate. Persistence, backed by clear records, is usually what gets a stubborn problem fixed. If the matter is urgent or causing hardship, say so clearly in your letter and ask HMRC to prioritise it, as they have processes for cases where a delay is causing real financial difficulty.

Check what you might be owed first

Before you write, it is worth checking whether you are actually due money back. Our tax refund calculator and tax code checker can confirm the figures, the Marriage Allowance calculator shows a commonly missed claim, and the income tax calculator helps you check your overall position. Putting a specific number in your letter makes your request concrete and harder to dismiss.

Key takeaways

• Complain when HMRC makes a mistake, delays, or gives poor service; appeal if you disagree with a decision.
• Keep your letter factual: facts in date order, reference numbers, the impact, and what you want done.
• Complaints escalate through two HMRC tiers, then the independent Adjudicator's Office.
• Keep copies and dates, and chase if you do not get a timely response.
• Check what you are owed first so your letter states a specific figure.

This tool produces a letter for you to review and send yourself. It is general help, not legal or tax advice - check your own circumstances or speak to HMRC or a qualified adviser if you are unsure.