HMRC Reasonable Excuse: How to Appeal a Late Filing or Payment Penalty 2026/27
What counts as a reasonable excuse for an HMRC late filing or late payment penalty, HMRC's own examples, what does not qualify, and the appeal process and time limits.
What Is a Reasonable Excuse?
When HMRC issues a penalty for a late tax return or late payment, you have the right to appeal if you believe you have a "reasonable excuse" -- a recognised legal ground that can result in the penalty being cancelled. HMRC defines a reasonable excuse as something unexpected, or outside your control, that stopped you meeting a tax obligation despite you otherwise taking reasonable care to meet it.
There is no fixed, exhaustive list in law of what does and does not qualify -- each case is decided on its own facts, and ultimately, if HMRC disagrees, an independent tribunal can decide. However, HMRC's internal manuals and published guidance give a strong steer on the kind of situations that are typically accepted.
Examples HMRC Accepts as Reasonable Excuse
HMRC's guidance sets out several recurring categories of accepted reasonable excuse:
- Bereavement: the death of a partner or close relative shortly before the filing or payment deadline.
- Serious illness or hospital stay: an unexpected illness, or you or someone you depend on being hospitalised, that prevented you dealing with your tax affairs during the relevant period.
- Failure of HMRC's own online services: if HMRC's website or online filing system was down and prevented you from filing on time, this is generally accepted, provided you can show you attempted to file before the deadline.
- Fire, flood or theft: an unexpected disaster that destroyed records or otherwise prevented you from completing your return or payment in time.
- Postal delays: delays in the postal service that were genuinely unpredictable, provided you can show you posted the return or payment in good time, allowing for normal delivery times.
- A partner or close relative's serious illness that meant you had to prioritise caring responsibilities over your tax affairs.
What Does NOT Count as a Reasonable Excuse
HMRC and the tribunals have consistently rejected certain categories of excuse, even though taxpayers often assume they will be accepted:
- Relying on someone else to file or pay on time. If you appointed an accountant or agent and they failed to file your return, this is generally not accepted as a reasonable excuse on its own -- the responsibility for filing on time remains with you. You may have a stronger case if you can show you gave clear, timely instructions and had no reason to suspect anything had gone wrong.
- Not having enough money to pay the tax. Insufficient funds alone is specifically excluded as a reasonable excuse by legislation. However, the underlying reason you ran out of money -- for example, a client going into insolvency and leaving you unexpectedly unable to pay -- might itself be considered, if it was genuinely unforeseeable.
- Finding the online system difficult to use. General unfamiliarity or difficulty navigating HMRC's systems, as opposed to an actual system failure, is not usually accepted.
- Forgetting the deadline. Simply forgetting, without some other unusual and unexpected factor, does not meet the test.
Reasonable Excuse vs Special Circumstances
It is worth understanding the distinction between two separate grounds that can both reduce or cancel a penalty:
| Ground | What it tests | Example |
|---|---|---|
| Reasonable excuse | Why you were late -- was it unexpected and outside your control? | Sudden hospitalisation prevented you filing |
| Special circumstances | Would it be unfair or disproportionate to apply the penalty, even without a strict reasonable excuse? | A technical, low-value error where the penalty is wildly disproportionate to any tax lost |
Special circumstances is a broader, fairness-based discretion available to HMRC and the tribunal, separate from the reasonable excuse test. You do not need a reasonable excuse to argue special circumstances, and the two can be raised together in the same appeal if relevant, though they are considered on different bases.
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If a penalty has arisen alongside a Self Assessment tax bill, use the self-employed tax calculator to check your underlying liability is correct before appealing.The Appeal Process
Step 1: Check the penalty notice. It will confirm the type of penalty, the amount, and the deadline for appealing -- generally 30 days from the date of the notice.
Step 2: Decide your grounds. Identify whether you are arguing reasonable excuse, special circumstances, or that the penalty was simply calculated incorrectly (for example, because you actually filed on time and have evidence of this).
Step 3: Submit your appeal. For many Self Assessment penalties this can be done online via your Personal Tax Account, or by post using form SA370. Other penalty types (VAT, PAYE, Corporation Tax) have their own equivalent appeal routes, generally accessible through your Business Tax Account or by letter.
Step 4: Provide evidence. Attach or reference any supporting evidence -- medical letters, death certificates, screenshots of system errors, proof of postage -- as this significantly strengthens your case.
Step 5: Await HMRC's decision. HMRC will review the appeal and either accept it (cancelling the penalty), partially accept it, or reject it with reasons.
If HMRC Rejects Your Appeal
If your appeal is rejected, you have two main options, both generally subject to a further 30-day time limit from the date of the rejection letter:
- Request an internal review. A different HMRC officer, not involved in the original decision, reconsiders the case.
- Appeal to the First-tier Tribunal (Tax Chamber). This is an independent tribunal, separate from HMRC, that can consider your case afresh. Many reasonable excuse appeals that reach this stage are conducted on paper or by telephone hearing rather than requiring an in-person hearing, particularly for lower-value penalties.
You can request an internal review first and still go on to the tribunal afterwards if you remain unsuccessful, though the time limit for the tribunal appeal generally runs from the original decision unless you have specifically agreed an extension with HMRC as part of the review.
Acting Promptly Once the Excuse Ends
A recurring theme in successful and unsuccessful reasonable excuse cases alike is what happened after the original problem was resolved. HMRC -- and tribunals -- expect you to file the return or make the payment without unreasonable further delay once you were able to do so again. If you were hospitalised for two weeks but then waited a further three months to file with no further explanation, that gap can undermine an otherwise genuine excuse, even though the original illness was real.
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Frequently asked questions
What is a reasonable excuse for HMRC penalty purposes?
A reasonable excuse is something unexpected or outside your control that stopped you from meeting a tax obligation, such as filing a return or making a payment on time, despite you having taken reasonable care to meet the deadline. HMRC assesses each case on its own facts rather than working from a fixed checklist, but its manuals give clear examples of what typically qualifies and what does not.
What examples does HMRC give of a reasonable excuse?
HMRC's own examples include the death of a partner or close relative shortly before the deadline, an unexpected stay in hospital or serious illness that prevented you from dealing with your tax affairs, a failure of HMRC's own online services near the deadline, delays caused by a fire, flood or theft that prevented you accessing your records, and postal delays you could not have predicted, provided you posted in good time.
What does NOT count as a reasonable excuse?
HMRC generally does not accept relying on someone else (such as an accountant or agent) to file on time as a reasonable excuse on its own, unless you can show you took reasonable care to ensure they did so. Simply not having enough money to pay a tax bill is also not a reasonable excuse on its own, though the underlying reason you have no money might be, if it was genuinely unforeseeable and outside your control.
What is the difference between reasonable excuse and special circumstances?
Reasonable excuse is a specific legal test about why you missed a deadline. Special circumstances is a separate, broader discretion HMRC (or a tribunal) can apply to reduce or cancel a penalty even where no strict reasonable excuse exists, if it would be genuinely unfair or disproportionate to apply the penalty in full. The two grounds can be argued together but are assessed differently.
How long do I have to appeal an HMRC penalty?
You generally have 30 days from the date of the penalty notice to appeal, either online through your HMRC account, by post, or in some cases by phone. Appealing late is possible in limited circumstances if you have a reasonable excuse for the lateness of the appeal itself, but this makes an already uncertain process harder.
Can I appeal an HMRC penalty online?
Yes, for many penalties, including Self Assessment late filing and late payment penalties, you can appeal online through your Personal Tax Account or Business Tax Account, or use the paper form (SA370 for Self Assessment penalties) if you prefer or if online appeal is not available for your specific penalty type.
What happens if HMRC rejects my reasonable excuse appeal?
If HMRC rejects your appeal, you can ask for an internal review by a different HMRC officer, or appeal directly to the independent First-tier Tribunal (Tax Chamber). Both routes have their own time limits, generally 30 days from the rejection decision, so it is important to act promptly rather than waiting.
Do I still need to pay the tax while I appeal a penalty?
Generally yes -- appealing a penalty does not automatically postpone the underlying tax liability, and interest continues to accrue on unpaid tax regardless of a penalty appeal. If you are also disputing the tax itself (not just the penalty), you can apply separately to postpone payment of the disputed tax pending the outcome, but this is a different process from a reasonable excuse penalty appeal.
Can I get a penalty cancelled if I fixed the problem as soon as possible?
Acting promptly once the reasonable excuse ends is an important part of a successful appeal. HMRC expects you to file the return or make the payment without unreasonable further delay once the original reason for the excuse (illness, bereavement, system failure, and so on) has been resolved. A long unexplained gap between the excuse ending and you actually filing or paying can undermine an otherwise strong case.
Does having a reasonable excuse remove the underlying tax I owe?
No. A successful reasonable excuse appeal cancels or reduces the penalty for being late, but it does not remove your obligation to pay the tax that was actually due, or the interest that accrues on late payment. Reasonable excuse is only about the penalty, not the tax debt itself.
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