Self Assessment Tax Penalties: How to Appeal to the Tribunal

How Self-Assessment Penalties Work

Self-assessment is the system by which individuals report their income and capital gains to HMRC and pay the tax due. If you are within the self-assessment system — whether as a sole trader, landlord, company director, or higher-rate taxpayer — you are legally required to file a return by the deadline and pay the tax on time.

When you miss these deadlines, HMRC imposes automatic penalties. Understanding the penalty structure is the first step to deciding whether to appeal.

Late Filing Penalties

The penalties for filing a self-assessment tax return late are set out in Schedule 55 of the Finance Act 2009:

This means that a return filed 12 months late could attract at least £1,600 in penalties — £1,000 plus the greater of £600 and 10% of the tax due — and more if information was deliberately withheld (Sch 55 paras 3–6), before any interest is added.

A change to watch: For Making Tax Digital users (qualifying income over £50,000 in 2024-25, required from 6 April 2026), FA 2021 Sch 24–26 apply to returns and payments for 2026-27 onwards (SI 2026/370); the 2025-26 return (due 31 January 2027) is still under Sch 55 and 56.

Late Payment Penalties

Separate penalties apply for paying your tax late. These are set out in Schedule 56 of the Finance Act 2009:

These penalties are cumulative. A taxpayer who pays 12 months late faces total penalties of 15% of the tax outstanding, plus statutory interest.

Interest

On top of penalties, HMRC charges interest on overdue tax from the due date until the date of payment. The interest rate changes periodically but has been significantly higher since the Bank of England base rate increases of 2022-2024. Late payment interest is Bank Rate plus 4% (from 6 April 2025); 7.75% from 9 January 2026 (GOV.UK, checked 27 September 2026).

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The Reasonable Excuse Defence

The most important defence to a self-assessment penalty is "reasonable excuse." If you can show that you had a reasonable excuse for the late filing or late payment, the penalty must be cancelled.

What the Law Says

Paragraph 23 of Schedule 55 FA 2009 (for late filing) and paragraph 16 of Schedule 56 FA 2009 (for late payment) provide that a penalty does not arise if the taxpayer satisfies HMRC — or, on appeal, the tribunal — that there was a reasonable excuse for the failure.

The legislation adds two important conditions:

1. The excuse must persist — if the excuse ceases, you must comply without unreasonable delay
2. Reliance on a third party is not automatically reasonable — nor is insufficiency of funds, unless attributable to events beyond your control

What Counts as a Reasonable Excuse?

The tribunal takes a practical approach. The question is whether, viewed objectively, what happened amounts to a reasonable excuse for this taxpayer, taking account of their experience and situation (Perrin at [81]). There is no exhaustive list, but the following have been accepted by tribunals:

Building Your Reasonable Excuse Case

To succeed with a reasonable excuse defence, you need evidence. The tribunal will want to see:

1. What happened — a clear factual account of the circumstances
2. When it happened — the timing relative to the filing or payment deadline
3. How it prevented compliance — the causal link between the excuse and the failure
4. What you did when the excuse ended — evidence that you filed or paid without unreasonable delay once the excuse ceased
5. Supporting documents — medical certificates, hospital records, death certificates, HMRC correspondence, screenshots of IT failures, or other contemporaneous evidence

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How to Appeal a Self-Assessment Penalty

You have three options for challenging a penalty, and it is important to understand them in order.

Option 1: Appeal Directly to HMRC

You can write to HMRC (or use the online service) to appeal the penalty. Your appeal should:

• Quote your Unique Taxpayer Reference (UTR) and the penalty reference number
• State clearly that you are appealing the penalty
• Set out your reasonable excuse in detail
• Attach supporting evidence
• Confirm the date on which the excuse ended and the date you filed or paid

HMRC will consider your appeal and either cancel the penalty, reduce it, or uphold it.

Option 2: Request an Internal Review

After HMRC gives its view on your appeal, you have 30 days to accept an offered review or notify the tribunal (s.49C/49H). A different HMRC officer — one who was not involved in the original decision — will re-examine the case. HMRC must give its conclusions within 45 days unless a different period is agreed (s.49E(6)).

Reviews are usually quicker than an appeal to the tribunal (GOV.UK).

Option 3: Appeal to the First-tier Tribunal

If the internal review upholds the penalty (or if you prefer to bypass the review), you can notify the appeal to the First-tier Tribunal (Tax Chamber) within 30 days of the review conclusion letter (s.49G) or, if you did not take up HMRC's offer of review, within 30 days of the offer (s.49H). There is no filing fee.

The tribunal is independent of HMRC and will look at your case afresh. Not every case has a hearing, but you can ask for one (GOV.UK; FTT r.26(7), r.29(1)). For reasonable excuse appeals, an oral hearing is usually preferable — it gives you the opportunity to explain the circumstances in your own words and answer the judge's questions.

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Preparing Your Appeal Bundle for the Tribunal

If your appeal reaches the tribunal, you will need to prepare a bundle containing all the documents relevant to the dispute.

What to Include

Organising Your Bundle

The tribunal expects a paginated, indexed bundle. Number every page consecutively from page 1, and include an index at the front listing each document with its page reference. For electronic bundles, include bookmarks and ensure the PDF is text-searchable.

A well-organised bundle demonstrates to the tribunal that you are taking the process seriously. It also makes the hearing run more smoothly, because the judge can find documents quickly when you refer to them.

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What Happens at the Tribunal Hearing

Self-assessment penalty appeals are often allocated to the Default Paper category; you can ask in writing for a hearing (r.26(7)). Always request an oral hearing if your case depends on explaining your personal circumstances — a letter cannot convey the same impact as a person explaining what happened to them.

The Hearing Process

1. The judge confirms the issues — typically, whether you had a reasonable excuse and whether you remedied the failure without unreasonable delay
2. HMRC presents its case — often briefly, relying on the statement of case already filed
3. You present your case — this is your opportunity to explain what happened, referring to your bundle
4. Questions from the judge — the judge may ask for clarification on specific points
5. Decision — the judge may give a decision immediately or reserve it

Tips for the Hearing

• Prepare thoroughly — know your bundle inside out
• Be honest — if part of the delay was your own oversight, say so, but explain the circumstances
• Focus on the excuse, not the unfairness — "the penalty is too harsh" is not a legal argument; "I had a reasonable excuse" is
• Have the bundle available on your device — the tribunal usually sends it by email (GOV.UK)
• Stay calm — the tribunal is used to hearing from unrepresented taxpayers and will be patient

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Common Pitfalls to Avoid

1. "I Didn't Know I Had to File"

Ignorance of a requirement can be a reasonable excuse if it was objectively reasonable for you not to know (Perrin at [82]); ignorance of a well-known requirement such as filing after a notice to file (SA316) rarely is. If HMRC issued you with a notice to file, you are legally obliged to file a return, whether or not you have tax to pay.

2. "My Accountant Was Supposed to Do It"

Reliance on a third party is specifically excluded from the reasonable excuse defence by the legislation — unless you took reasonable care to avoid the failure (Sch 55 para 23(2)(b)).

3. "I Couldn't Afford to Pay"

Insufficiency of funds is not a reasonable excuse for late payment — unless the shortfall was caused by something beyond your control, such as a client going bankrupt and failing to pay a large invoice.

4. Waiting Too Long to Appeal

You have 30 days from the date of the penalty notice to appeal to HMRC (TMA 1970 s.31A; FA 2009 Sch 55 para 21). If you miss this deadline, ask HMRC in writing to accept a late appeal; if HMRC do not agree, you can ask the tribunal for permission (TMA 1970 s.49). The longer the delay, the harder it becomes to justify.

5. Not Filing Even After the Penalty

If you still have not filed the return, file it now. Even if you are appealing the penalty, continuing not to file attracts further penalties and undermines your credibility.

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Using BundleCreator for Penalty Appeals

Putting together a penalty appeal bundle — organising medical evidence, HMRC letters, and your timeline into a paginated, indexed document — is a task that BundleCreator makes straightforward.

With BundleCreator, you can:

• Upload all your evidence, correspondence, and tax documents
• Arrange them in a logical order with simple drag-and-drop
• Apply automatic consecutive pagination
• Generate a hyperlinked index and PDF bookmarks
• Ensure your bundle is text-searchable and professionally formatted
• Export a tribunal-ready bundle in minutes

A professional bundle shows the tribunal you have taken your appeal seriously — and BundleCreator handles the formatting so you can focus on your case.

Start preparing your penalty appeal bundle →

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Frequently Asked Questions

Can I appeal a self-assessment penalty if I had no tax to pay?

Yes. The initial £100 late filing penalty applies whether or not you owe any tax. You can still appeal on the basis of reasonable excuse — the absence of tax due does not affect the penalty itself. The tribunal cannot cancel a penalty because it considers it unfair or disproportionate (HMRC v Hok Ltd [2012] UKUT 363 (TCC) at [56]–[58]); it may substitute a special reduction only if HMRC's decision was flawed (Sch 55 para 22(3)–(4)).

How long does HMRC take to respond to a penalty appeal?

No statutory time limit applies to HMRC's response to your appeal. If HMRC has not given its view, you can require a review or notify the appeal to the tribunal yourself (TMA ss.49B, 49D).

Is there a fee to appeal to the tax tribunal?

No. There is no filing fee for appeals to the First-tier Tribunal (Tax Chamber). This applies to self-assessment penalty appeals and all other tax appeals.

What if I have multiple penalties for the same tax year?

You can appeal multiple penalties in a single notice of appeal. If the same reasonable excuse applies to all the penalties (for example, you were hospitalised during the entire period), you should explain this once and make clear that it covers all the penalties.

Can HMRC waive a penalty without me appealing?

HMRC has the power to reduce or cancel penalties in certain circumstances — for example, under its collection and management powers or where special circumstances exist. However, this is rare, and you should not rely on HMRC's discretion. If you believe the penalty is wrong, appeal formally.

What if my accountant admits it was their fault?

If your accountant accepts that the failure was their professional error, obtain a written admission from them. While reliance on a third party is not automatically a reasonable excuse, evidence that you took reasonable care to avoid the failure — for example, that you gave your accountant everything in good time and checked that the return had been filed — can support your appeal (FA 2009 Sch 55 para 23(2)(b); Sch 56 para 16(2)(b)).

Can penalties be suspended?

Late filing and late payment penalties under Schedules 55 and 56 FA 2009 cannot be suspended. Only careless-inaccuracy penalties can be suspended (Sch 24 para 14(1)), if HMRC agrees conditions — for example, improving your record-keeping. This distinction matters if you are facing multiple types of penalty.

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This article is provided for general informational purposes only and does not constitute legal or tax advice. The law and procedure described applies to England and Wales. If you are unsure about your specific situation, seek independent legal or professional advice.