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Understanding Your Appeal Rights: What HMRC Letters Actually Mean

Not every HMRC letter can be appealed. Here's how to tell if yours can—and what to do next.

Liam Williams

16 Jan 2026 — 3 min read

You've received a letter from HMRC. It says you owe money, or they've changed your tax, or they're charging you a penalty. Your first question is probably: can I challenge this?

The answer depends on what kind of decision HMRC has made—and whether you act quickly enough.

Not Every HMRC Letter Can Be Appealed

HMRC sends millions of letters each year. Most are routine—statements, reminders, requests for information. These don't have appeal rights because there's no "decision" to challenge.

But some letters contain appealable decisions. These include:

Penalties for late returns, late payments, or inaccurate returns
Tax assessments where HMRC has calculated what you owe
Closure notices ending an enquiry into your tax return
VAT decisions about registration, assessments, or penalties
Tax credit and Child Benefit decisions

If your letter contains an appealable decision, it will say so. Look for a section headed "Your rights" or "How to appeal" near the end of the letter.

The 30 days Deadline

Here's the critical part: you usually have 30 days to respond. This is 30 days from the date printed on the letter—not 30 days from when you received it.

If your letter sat in a pile for a week before you opened it, that week counts against you.

Miss the deadline and HMRC will treat their decision as final. You can still ask for a late appeal, but you'll need a good reason for the delay, and HMRC doesn't have to accept it.

Your Two Options

When you disagree with an HMRC decision, you have two main paths.

Option 1: Ask HMRC for a Review

A review is an internal HMRC process. A different officer—one who wasn't involved in the original decision—looks at your case again. They work in HMRC's Solicitor's Office and Legal Services, separate from the team that made the decision.

HMRC has 45 days to complete the review. At the end, they'll either:

Uphold the original decision (no change)
Vary the decision (change it somewhat)
Cancel the decision entirely

Reviews are free and usually faster than going to the tribunal. If you disagree with the review outcome, you still have the right to appeal to the tribunal—you haven't given anything up.

Option 2: Appeal to the Tax Tribunal

The First-tier Tribunal (Tax Chamber) is independent of HMRC. A judge (or panel) will hear both sides and make a decision.

You can appeal directly to the tribunal without asking for a review first. But for most disputes, trying a review first makes sense—it's quicker, costs nothing, and over 12,000 HMRC decisions are changed through reviews each year.

The Third Path: Review, Then Tribunal

Most people choose this route:

Ask HMRC for a review
Wait for the outcome (45 days)
If you still disagree, appeal to the tribunal within 30 days of the review conclusion letter

This gives you two chances to resolve the dispute before involving a tribunal.

Direct Tax vs Indirect Tax: A Key Difference

The process differs slightly depending on what type of tax is involved.

For direct taxes (Income Tax, Capital Gains Tax, Corporation Tax, National Insurance, Inheritance Tax):

You appeal to HMRC first
HMRC may try to resolve things informally
If not resolved, HMRC offers you a review
You have 30 days to accept the review or go straight to tribunal

For indirect taxes (VAT, excise duty, customs duty):

HMRC automatically offers a review in the decision letter itself
You have 30 days to accept the review or appeal to tribunal

The deadlines are the same. The difference is when the review is offered.

What If You Miss the Deadline?

You can ask HMRC to accept a late appeal if you have a "reasonable excuse"—something that genuinely prevented you from responding in time. Examples might include serious illness, bereavement, or postal problems.

HMRC doesn't have to accept late appeals. If they refuse, you can ask the tribunal to allow a late appeal, but you'll need to explain the delay and show you acted as soon as you could.

The safest approach: don't miss the deadline. If you need more time to prepare your arguments, you can appeal within 30 days and provide full details later.

What To Do Now

If you've received an HMRC decision letter:

Check the date on the letter and count 30 days forward
Find the appeal section—usually near the end, headed "Your rights" or "How to appeal"
Decide your approach: review, direct tribunal appeal, or accept the decision
Respond in writing before the deadline, even if you're still gathering information

You can appeal online for some decisions (like Self Assessment penalties) through your HMRC online account. For others, you'll need to write to the address on the letter.