HMRC Interest & Penalty Reduction (2026): When Late Payment Interest or Fines Can Be Reduced — Evidence Checklist & Appeal Template

Quick Summary (60 seconds)

• Penalties can often be reduced or cancelled if you had a reasonable excuse and you acted as soon as you could.
• Interest is usually statutory, but HMRC has limited discretion to reduce it in specific situations (for example, certain HMRC delays or errors).
• HMRC late payment interest is linked to the Bank of England base rate. The current late payment interest rate is 7.75% from 9 January 2026.
• You usually have 30 days from the date of a decision/penalty letter to appeal or accept a review.

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Why this topic is expensive (and urgent)

Late payment interest compounds the longer a balance stays unpaid. Since 6 April 2025, HMRC late payment interest is set at base rate + 4%, which makes delays materially more costly. In 2026, the current late payment interest rate is 7.75% (from 9 January 2026).

Contents

1. Can HMRC reduce penalties or interest?
2. What counts as a “reasonable excuse” (and what does not)
3. Deadlines: how long you have to appeal
4. When HMRC may reduce interest (and when it won’t)
5. Evidence checklist (save this)
6. Appeal template (copy/paste)
7. More official help (authoritative links)

Can HMRC reduce penalties or interest?

Penalties: yes, often — if you can prove the right ground

For many penalties (late filing, late payment, errors, failure to notify), HMRC can accept an appeal where you had a reasonable excuse and you put things right as soon as you were able.

Penalties can also be reduced in “special circumstances” (limited)

HMRC guidance explains “special reduction” as a discretionary reduction below the amount otherwise provided for in law, but only where special circumstances exist. This is separate from reasonable excuse and is not common.

Interest: usually no — but there are limited exceptions

HMRC interest is generally statutory and charged automatically on late payment. However, there are limited cases where HMRC may waive or reduce all or part of interest — for example, where HMRC provides erroneous advice or unreasonably delays resolving a dispute (interest review processes may apply).

What counts as a “reasonable excuse” in 2026

GOV.UK examples of what may count include:

• bereavement (partner or close relative died shortly before the deadline)
• unexpected hospital stay or serious illness
• computer/software failure while preparing an online return
• HMRC online service issues
• fire, flood, theft, postal delays you could not have predicted
• delays related to disability or mental illness
• reliance on someone else who failed to act

And GOV.UK also lists examples that will not usually be accepted, such as:

• payment failed because you did not have enough money
• finding HMRC online systems too difficult
• not getting a reminder
• making a mistake on your tax return

Key rule: you must send the return or payment as soon as you’re able once the issue ends.

Deadlines: how long you have to appeal

You usually have 30 days from the date of the decision/penalty letter to appeal or accept a review. If you miss the deadline, you’ll generally need to explain a reasonable excuse for being late.

If you do not have an appeal form, GOV.UK says you can send a signed letter to the HMRC office related to your return, explaining why you were late (including dates), and include your name and reference number (for example your UTR). If the issue was a computer problem, include the date you tried to file/pay and any error message details.

When HMRC may reduce interest (and when it won’t)

In most cases, you should expect interest to remain payable on late tax. Interest reduction is more realistic when:

• HMRC gave incorrect advice that you relied on, or
• there was an unreasonable HMRC delay in resolving a dispute, and
• you can document the timeline (dates, calls, letters, online screenshots).

If your main issue is cashflow rather than disputing the charge, it may be more practical to explore a Time to Pay arrangement to stop penalties escalating (interest can still apply).

Evidence Checklist (Save this)

Tip: Your chances rise when you prove (1) what happened, (2) when, and (3) how it stopped you meeting the obligation — plus (4) what you did immediately afterwards.

Reason you’re relying on	Evidence to attach
Serious illness / hospital stay	hospital letter/discharge note, GP letter, dates you were unwell, proof of incapacity
Bereavement	death certificate, funeral documents, timeline showing proximity to deadline
Fire / flood / theft	police/crime reference, insurance claim, photos, evacuation notice, repair invoices
IT failure / HMRC online issues	screenshots of error messages, date/time attempted, reference numbers, browser logs (if available)
Postal delays	proof of posting, tracked delivery records, Royal Mail notices, dates
HMRC delay / incorrect advice	copies of HMRC letters, call logs, names (if known), dates, complaint history, timeline

Appeal Template (copy/paste)

Use this when you do not have a dedicated appeal form. Keep it factual, date-driven, and evidence-backed.

[Your full name / business name]
[Address]
[Postcode]
[UTR / VAT number / PAYE reference / relevant reference]
[Phone] [Email]
[Date]

HM Revenue and Customs
[Address shown on your penalty/decision letter]

Subject: Appeal against HMRC penalty / request for penalty cancellation (Reasonable Excuse)

Dear HMRC Officer,

I am writing to appeal the penalty dated [DD/MM/YYYY] relating to [tax type: Self Assessment / VAT / PAYE / Corporation Tax] for the period [period / tax year].

1) What happened (timeline with dates)
- [DD/MM/YYYY]: [Event – e.g., unexpected hospital admission / bereavement / fire / HMRC online outage]
- [DD/MM/YYYY]: [How it directly prevented filing/payment]
- [DD/MM/YYYY]: [When the issue ended / when you were able to act]

2) Why this is a reasonable excuse
This circumstance was outside my control and directly prevented me from meeting the obligation by the deadline.

3) What I did as soon as I could
I [filed the return / made payment / contacted HMRC / set up Time to Pay] on [DD/MM/YYYY], immediately after I was able to do so.

4) Evidence attached
- [List documents: hospital letter dated..., screenshots of error..., police reference..., etc.]

I respectfully request that HMRC cancel or reduce the penalty on the basis of reasonable excuse. If HMRC does not change the decision, please treat this letter as a request for a review.

Yours faithfully,

[Signature]
[Your printed name]

More official help (reputable sources)

• GOV.UK: Reasonable excuses (HMRC appeals)
• GOV.UK: Disagree with a penalty (how to appeal / review / tribunal)
• GOV.UK: Disagree with a tax decision (30-day rules)
• GOV.UK: HMRC late/repayment interest rates (updated)
• GOV.UK: If you cannot pay your tax bill on time (Time to Pay)
• HMRC Compliance Handbook: Special reduction (overview)

Sources

• GOV.UK — Reasonable excuses
• GOV.UK — Disagree with a penalty
• GOV.UK — Disagree with a tax decision
• GOV.UK — HMRC interest rates (late payment 7.75% from 9 Jan 2026; base rate + 4% from 6 Apr 2025)
• GOV.UK — If you cannot pay your tax bill on time (Time to Pay)
• HMRC internal manual — Special reduction (overview)