Guides

The Complete Timeline of a UK Tax Dispute

A roadmap of every stage from HMRC decision to final resolution—with the deadlines, exit points, and danger zones that most guides don't mention.

Liam Williams

27 Feb 2026 — 11 min read

Most tax disputes never reach a hearing. Of the tens of thousands of disputes that begin each year, only around 1,500 end up in front of a tribunal judge. Around 75% settle after a statutory review alone. Most of the rest resolve through negotiation or agreement before a hearing is listed.

Understanding where and when disputes end is worth more than knowing what happens at a hearing. This article maps the entire journey—from the HMRC letter that starts the clock to the final resolution—with the deadlines, exit points, and danger zones at every stage.

The statistics below are drawn from multiple years of published data and are approximate—they show the shape of the process, not precise figures for any single year.

The Dispute Funnel

A UK tax dispute follows a funnel. Millions of HMRC decisions go out each year. A fraction are appealed. A fraction of those reach the tribunal. A fraction of those reach a hearing. The numbers narrow at every stage:

Appeals initiated — around 40,000 per year (estimated from HMRC's live caseload)
Statutory reviews conducted — around 22,000 per year
Appeals filed at the First-tier Tribunal — around 12,000–13,000 per year
Cases reaching a hearing — around 1,500 per year
Appeals to the Upper Tribunal — likely low hundreds per year
Court of Appeal — a handful per year
Supreme Court — 0–2 tax cases per year

Your most likely outcome is resolution before a hearing. But that only works in your favour if you meet every deadline along the way. Miss one—or simply fail to respond—and your dispute can end permanently on HMRC's terms.

Interest and Enforcement

One thing that catches many appellants off guard: interest on unpaid tax accrues throughout the entire dispute, from the original due date until payment—regardless of whether you've appealed. Winning your appeal cancels the interest along with the tax, but if the dispute takes 12 months and you lose, you owe 12 months of additional interest.

For direct taxes, if you've filed a valid appeal, HMRC generally cannot take enforcement action on the disputed amount—but only if you've also applied to postpone payment under s.55 TMA 1970. Without a postponement application, the tax remains due and HMRC can pursue collection. For penalties, HMRC will normally not enforce while an appeal is pending.

Two Routes, One Destination

The UK tax system splits into two paths depending on the type of tax:

Direct taxes (income tax, capital gains tax, corporation tax, National Insurance, inheritance tax) follow Part V of the Taxes Management Act 1970. You must appeal to HMRC first before the tribunal gets involved.
Indirect taxes (VAT, customs duty, excise duty, insurance premium tax, landfill tax) follow Part V of the Value Added Tax Act 1994. You can appeal directly to the tribunal.

This article follows the direct taxes route as the default and flags where indirect taxes differ. Both routes converge once your case reaches the tribunal.

Phase 0—The Enquiry (Before Day 0)

Many disputes begin with an HMRC enquiry into your tax return—a formal compliance check that can last months or years before producing the decision that triggers your appeal rights. If you're currently in an enquiry, our guide to HMRC enquiries and closure notices covers what to expect, your rights during the process, and how the closure notice works.

Phase 1—HMRC Has Control (Days 0–75)

The Decision Letter (Day 0)

Everything starts with an HMRC decision. It might be a penalty notice, a tax assessment, a closure notice after an enquiry, or a VAT decision. Not every letter from HMRC is appealable—only specific statutory decisions carry a right of appeal.

The decision letter should include a section headed "Your rights" or "How to appeal." If it does, the 30 days clock starts from the date on the letter—not the date you received it.

Exit point: You accept the decision and pay. The dispute ends here.

If you're not sure whether your letter carries appeal rights, our guide to understanding your appeal rights explains what to look for. If the decision involves a penalty, HMRC penalties explained covers the different types and how they work.

Your Response (Days 1–30)

What you do next depends on the type of tax.

Direct taxes: You must appeal to HMRC in writing within 30 days of the decision, under section 31A TMA 1970. Your notice must state the grounds of appeal—why you think HMRC got it wrong. This appeal goes to HMRC, not to the tribunal. Only after HMRC has your appeal can the dispute move forward.

Indirect taxes: HMRC must offer you a review at the same time as the decision (section 83A VATA 1994). You can accept the review offer, or you can bypass HMRC entirely and appeal straight to the tribunal within 30 days under section 83G VATA 1994.

If you're appealing a direct tax assessment and want to pause payment while the dispute is resolved, you need to apply for postponement under section 55 TMA 1970 within 30 days. For indirect taxes, you must pay the disputed tax or demonstrate hardship under section 84 VATA 1994. Either way, don't let the payment question cause you to miss the filing deadline.

Our step-by-step guide to filing your appeal covers exactly how to do this—including which route applies to you, what to include, and the critical difference in timing between direct and indirect taxes.

Exit point: Informal resolution with the HMRC caseworker. Some disputes resolve through straightforward correspondence at this stage, without needing a formal review or tribunal.

Danger zone—the inaction trap (direct taxes only): If HMRC offers you a statutory review and you don't respond within 30 days, your appeal is treated as settled in HMRC's favour under section 49C(4) TMA 1970. This isn't a pause. It's permanent and irrevocable—section 49C(5) prevents you from undoing it. A letter you ignore or miss could end your dispute for good.

Statutory Review (Days 30–75)

If you request or accept a review, a different HMRC officer—from the Solicitor's Office and Legal Services, outside the original decision-maker's chain of command—looks at your case independently.

HMRC has 45 days to complete the review (section 49E TMA 1970 / section 83F VATA 1994). If HMRC misses this deadline, the original decision is treated as upheld.

The reviewer reaches one of three conclusions:

Upheld — the original decision stands
Varied — the decision is changed (the amount might be reduced, for example)
Cancelled — the decision is withdrawn entirely

The numbers are encouraging. According to figures from HMRC's National Reviews Team (2019–20), around 56% of reviewed decisions were cancelled or varied in the taxpayer's favour. For VAT penalty cases involving reasonable excuse, that figure was around 81%.

Our detailed guide to HMRC's internal review covers how the process works, what to include in your request, and what to do with each outcome.

Exit point: The decision is cancelled or varied to your satisfaction. The dispute ends.

Danger zone—the post-review inaction trap (direct taxes only): If the review upholds or varies the decision and you don't notify your appeal to the tribunal within 30 days of the review conclusion, the review's conclusions become a deemed settlement in HMRC's favour under section 49F TMA 1970. As with the first inaction trap, this is permanent. There's no cooling-off period.

Phase 2—The Tribunal Takes Over (Months 3–36)

Filing Your Appeal

If HMRC's review upholds the decision—or if you chose not to request a review—the next step is the First-tier Tribunal (Tax Chamber).

For direct taxes, you "notify" your existing appeal to the tribunal under section 49G TMA 1970 within 30 days of the review conclusion. For indirect taxes, you appeal directly to the tribunal under section 83G VATA 1994 within 30 days of the decision (or review conclusion).

Filing costs £0—there's no fee to appeal to the tax tribunal. You can file online at appeal-tax-tribunal.service.gov.uk or by post/email using form T240.

If you've missed the deadline, it's not necessarily too late. The tribunal can grant permission for a late appeal, though you'll need to explain the delay. Our guide to late appeals explains the three-stage test the tribunal applies and what counts as a good reason.

Exit point: You decide not to pursue the appeal and accept HMRC's position.

Case Allocation and Management

The tribunal acknowledges your appeal and allocates it to one of four categories under Rule 23 of the Tribunal Procedure Rules:

Category	Typical Cases	Hearing Format	Costs Risk
Default Paper	Penalties up to £500, late filing/payment	On papers (can request oral)	No
Basic	Most penalty appeals, late-appeal applications	Video hearing	No
Standard	Substantive tax disputes, closure notices	Full hearing	Only if unreasonable conduct
Complex	Large sums, complex law, lengthy hearing	Full hearing	Yes (unless you opt out within 28 days)

The category determines how your case is managed—including HMRC's deadline to respond, whether you'll have a hearing, and whether you face costs risk. Our guide to tribunal tracks and costs covers each category in detail, including the 28-day opt-out for Complex cases.

After allocation, the tribunal issues directions—a procedural timetable setting out what each party must do and when. HMRC files a statement of case (within 42 days for Default Paper cases; 60 days for Standard/Complex), and the case moves through document exchange, statements of agreed facts, and hearing preparation.

For Standard and Complex cases, this process can take 12–36 months from filing to hearing. Basic cases are typically faster.

Settlement and ADR

Most cases resolve before a hearing. Settlement can happen at any point through direct negotiation with HMRC, or through alternative dispute resolution (ADR)—a free mediation service where an independent HMRC mediator helps both sides work towards agreement.

When you and HMRC reach agreement, it's formalised through section 54 TMA 1970 (direct taxes) or section 85 VATA 1994 (indirect taxes). The agreement has the same legal effect as a tribunal decision. You have a 30-day cooling-off period to change your mind before the settlement becomes final.

ADR is available for Standard and Complex cases but not Default Paper or Basic. In 2024-25, around 89% of concluded ADR cases reported a positive outcome.

Our guide to settling your tax tribunal case covers how negotiation works, what a section 54 agreement means, the cooling-off period, and how to apply for ADR.

Exit point: Full or partial settlement—the dispute ends (or narrows to the remaining issues).

The Hearing

If the case doesn't settle, it goes to a hearing. What this looks like depends on the category:

Default Paper — decided on the documents alone, unless you request an oral hearing
Basic — usually a short video hearing (Microsoft Teams)
Standard — a fuller hearing, in person or by video, with witness evidence and submissions
Complex — a full hearing, potentially lasting several days, with skeleton arguments, bundles, witnesses, and expert evidence

You'll receive at least 14 days' notice of the hearing date. Hearings are public unless the judge orders otherwise (Rule 32 of the Tribunal Procedure Rules). You present your case, HMRC presents theirs, both sides can question witnesses, and the judge may ask questions.

You don't need to be a lawyer to present your case. The tribunal is used to dealing with unrepresented appellants and will make reasonable allowances. But preparation matters. Know your key facts, organise your documents, and be ready to explain clearly why you believe HMRC's decision is wrong. Our guide to preparing for your tax tribunal hearing covers evidence, bundles, witness statements, and what to expect on the day.

The tribunal will issue its decision typically 6-12 months after filing—though the decision itself typically arrives within 12 weeks of the hearing.

HMRC's published success rate at the First-tier Tribunal is around 93% (2024-25). But that figure covers only cases that reach a hearing—the small fraction that didn't settle, withdraw, or resolve at earlier stages. It doesn't mean 93% of all tax disputes are decided in HMRC's favour.

Exit point: The tribunal determines the appeal. The decision is binding (subject to appeal on a point of law).

Phase 3—After the Decision

The FTT Decision

The tribunal issues a decision notice, usually with written reasons. If the decision notice doesn't include full reasons, you can request them within 28 days.

If you believe there's been a procedural error—for example, you weren't notified of the hearing, or important documents weren't considered—you can apply to have the decision set aside under Rule 38 of the Tribunal Procedure Rules. This must be "in the interests of justice." Our guide to what happens after your tax tribunal decision covers written reasons, setting aside, and the full Upper Tribunal appeals process.

Exit point: You accept the decision. The dispute ends.

Appeal to the Upper Tribunal

If you believe the tribunal got the law wrong, you can apply for permission to appeal to the Upper Tribunal (Tax and Chancery Chamber). This must be on a point of law—the Upper Tribunal doesn't rehear the facts. Disagreeing with the outcome isn't enough; you must identify a legal error such as misapplying the law, procedural unfairness, or inadequate reasoning.

The deadline is 56 days from the date the tribunal sends the decision notice. You apply to the First-tier Tribunal first (Rule 39 of the Tribunal Procedure Rules). If the FTT refuses, you can apply to the Upper Tribunal within one month (Rule 21 of the Upper Tribunal Rules).

There's one critical difference from the FTT: the costs regime applies. In the Upper Tribunal, the losing party typically pays the winning party's legal costs. This is a significant financial risk, especially if you're unrepresented.

Exit point: Permission refused (the FTT decision stands), or the Upper Tribunal decides the appeal.

Court of Appeal and Supreme Court

Appeals beyond the Upper Tribunal are rare and subject to increasingly high thresholds. An appeal to the Court of Appeal requires permission under section 13 TCEA 2007 and must raise an "important point of principle or practice" or show "some other compelling reason" for the court to hear it. The full costs regime applies.

The Supreme Court hears only a handful of tax cases each year—typically 0-2. Cases at this level raise points of law of general public importance. For most appellants, the realistic endpoint is the First-tier Tribunal decision or, at most, the Upper Tribunal.

Every Deadline at a Glance

Stage	Deadline	What Happens If You Miss It
Appeal to HMRC (direct taxes)	30 days from decision (s.31A TMA 1970)	Late appeal—HMRC or tribunal permission needed
Appeal to tribunal (indirect taxes)	30 days from decision (s.83G VATA 1994)	Tribunal permission needed for late appeal
Respond to HMRC's review offer (direct taxes)	30 days from HMRC's offer of review (s.49C TMA 1970)—accept review or notify tribunal	Deemed settlement under s.49C(4)—irrevocable
HMRC completes review	45 days from acceptance (s.49E TMA 1970)	Decision deemed upheld
Notify tribunal after review (direct taxes)	30 days from review conclusion (s.49G TMA 1970)	Deemed settlement under s.49F—irrevocable
Appeal to tribunal after review (indirect taxes)	30 days from review conclusion (s.83G VATA 1994)	Tribunal permission needed for late appeal
Apply to postpone tax (direct taxes)	30 days from assessment (s.55 TMA 1970)	Tax due and payable immediately
Opt out of Complex costs regime	28 days from allocation	Costs regime applies for remainder of case
Repudiate settlement agreement	30 days from agreement (s.54 TMA 1970)	Settlement becomes final and binding
Request full written reasons	28 days from decision notice	May lose ability to formulate a grounds of appeal
Apply for permission to appeal to UT	56 days from decision notice	Must request an extension; may be refused
Apply to UT if FTT refuses permission	1 month from refusal	Must request an extension

Where You Are Now

If you already know which stage you're at, the table below points you to the detailed guide:

Your Situation	Read This
Received an HICBC assessment or penalty	The High Income Child Benefit Charge
Under an HMRC enquiry or received a closure notice	HMRC Enquiries and Closure Notices
Just received an HMRC decision	Understanding Your Appeal Rights
Received a penalty notice	HMRC Penalties Explained
Received a Self Assessment penalty	Self-Assessment Penalties
Ready to file your appeal	How To Appeal to the Tax Tribunal
Missed the 30-day deadline	Late Appeals to the Tax Tribunal
Considering or going through a review	HMRC's Internal Review
Need a reasonable excuse defence	What Is a Reasonable Excuse?
Case allocated to a category	Tribunal Tracks and Costs
Negotiating, settling, or considering ADR	Settling Your Tax Tribunal Case
Preparing for a hearing	Preparing For Your Tax Tribunal Hearing
Received the tribunal's decision	After Your Tax Tribunal Decision

If you're not sure where you are in the process, start with Understanding Your Appeal Rights. It'll help you identify what type of decision you've received and what your options are.