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PARTLY

As of 13 August 2026, AI can only partly check if an HMRC penalty is correct.

This still needs a person who signs their name to it.

Can you do it?

15 minutesto a draft.

1 hourto something you’d act on.

Cost, all in£0

Skill neededchat-fluent

Who has to check ita professional

What the alternative costsNo listed commercial candidate is a tax adviser or quotes a price for checking an HMRC penalty.

If this goes wrong: you accept or challenge the penalty on a mistaken basis, and the error can leave you owing money or missing an appeal opportunity.

What to actually do

  1. Hand it to a person

    The route this page recommends

    Someone with a licence or accountable authority has to sign this before it counts.

  2. Use a tool built for this

    Second choice

  3. Do it yourself

    The distant third

    A chat interface, chat-fluent skill, and roughly 1 hour until you can act on the result.

    How to actually do it

    1. Open the HMRC penalty notice and copy out the full text, including the penalty type, tax year, amount, issue date, stated reason and appeal instructions.
    2. Gather the relevant tax return, submission confirmation, payment confirmations, bank records and every HMRC message about the filing or payment.
    3. Write a short timeline of what happened, using exact dates from your records, and attach evidence for any illness, bereavement, technical problem or other reason for delay.
    4. Paste the notice, timeline and supporting extracts into a chatbot with the supplied prompt, removing account numbers, National Insurance numbers and other unnecessary personal data.
    5. Compare the chatbot's stated rule, dates and arithmetic with the current penalty guidance on GOV.UK, and mark every claim that is not supported by either your documents or GOV.UK.
    6. Send the checked list of discrepancies and unanswered questions to HMRC through the contact route in the notice, or ask a UK tax adviser or accountant to assess the case before you rely on the analysis.

    Prompt

    Act as a UK tax-research assistant, not as my tax adviser. Analyse the HMRC penalty materials pasted below and help me check whether the penalty appears consistent with the published HMRC rules.

Materials:
- Penalty notice: [paste the full notice, including the penalty type, amount, tax year, dates and appeal instructions]
- Relevant tax return and filing details: [paste the relevant figures and filing or payment dates]
- Payment history: [paste dates, amounts and confirmation details]
- HMRC correspondence: [paste relevant messages or letters]
- Explanation and evidence for any delay or mistake: [paste the facts and list supporting documents]

Do not invent facts, deadlines, amounts or legal rules. Separate the analysis into:
1. facts established by the documents;
2. facts that are missing or uncertain;
3. the HMRC rule or GOV.UK guidance that appears relevant, with a direct GOV.UK link where available;
4. arithmetic checks of the penalty;
5. arguments that the penalty may be correct;
6. arguments that it may be wrong or that a reasonable-excuse appeal may be relevant;
7. the exact questions I should ask HMRC or a UK tax adviser;
8. a factual draft message to HMRC that makes no unsupported legal claim.

Do not tell me that the penalty is definitely correct or definitely invalid. Do not advise me to ignore the notice. Flag any point that needs confirmation from HMRC or a qualified UK tax adviser, and tell me what document would resolve it.

    Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.

What it gets wrong

  • AI cannot see HMRC's internal account notes, so it cannot know whether the notice reflects a missing submission, an unprocessed payment or an administrative error.
  • AI cannot decide whether your explanation meets the reasonable-excuse test in the context of all the evidence.
  • AI can use an outdated or incorrectly applied rule unless you check it against current GOV.UK guidance.
  • AI cannot take responsibility for the appeal, payment or consequences of an incorrect challenge.
  • AI cannot replace a UK tax adviser or accountant when the penalty is substantial, disputed or tied to wider return errors.

What caps this at PARTLY: legal accountability, judgement under ambiguity and verification cost.

How we scored this

Five axes, each scored nought to two by hand: ten means AI carries the task cleanly, and the thresholds that turn a total into YES, PARTLY or NO are published in the methodology. Each axis name links to its definition.

AxisScore (0–2)
Output1
Inputs1
Verification1
Liability1
Effort delta1
Total5 / 10

The methodology and its thresholds are published in full.

FAQ

Can AI tell me if my HMRC penalty is wrong?
It can compare the notice, your timeline and the published HMRC guidance, and identify figures or dates that do not match. It cannot make a reliable final decision where the case depends on disputed facts or a reasonable excuse.
Can I use ChatGPT to appeal an HMRC penalty?
Yes, it can help organise your evidence and draft a factual appeal for you to check. Do not rely on it to invent a legal argument or decide that you have a reasonable excuse. This is not professional advice.
What do I need to check an HMRC penalty?
Gather the penalty notice, the relevant return, filing and payment confirmations, HMRC correspondence and evidence explaining any delay. Compare the dates, amount and stated rule with current GOV.UK guidance before contacting HMRC.
Should I ask an accountant about an HMRC penalty?
Ask a UK tax adviser or accountant when the penalty is disputed, the facts are complicated or the amount could materially affect you. They can assess the evidence and help with the appeal, while you remain responsible for acting by the deadline in the notice.

Nearby answers

All Tax returns & HMRC rulings

Assessed by gpt-5.6-luna (gpt-5.6-luna) on 2026-08-13, second-checked by an independent model. Wrong somewhere? Email [email protected] and it gets re-checked.

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