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PARTLY

As of 13 August 2026, AI can only partly check whether an employee's tax code is correct.

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

Can you do it?

5 minutesto a draft.

30 minutesto something you’d act on.

Cost, all in£0

Skill neededchat-fluent

Who has to check ita professional

What the alternative costsA payroll adviser or accountant is the alternative; no price is supplied here.

If this goes wrong: the employee pays too much or too little tax and the payroll records need correction, with the responsibility remaining outside the chatbot.

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 30 minutes until you can act on the result.

    How to actually do it

    1. Open the employee's latest payslip and record the tax code, pay frequency, taxable pay, tax deducted and year-to-date totals.
    2. Open the employee's latest HMRC tax code notice, if available, and copy the code and each adjustment into the prompt.
    3. Gather the employee's P45 or previous employment details, other jobs or pensions, taxable benefits, pension contributions and any recent change reported to HMRC.
    4. Remove unrelated personal information, paste the records into the prompt, and ask the chatbot to identify missing information before judging the code.
    5. Compare the chatbot's explanation with the payslip and coding notice, then check the relevant current guidance on GOV.UK rather than relying on an uncited tax rule.
    6. Send any discrepancy and the supporting documents to the employer's payroll team; ask the employee to contact HMRC through GOV.UK or a qualified payroll adviser where the coding notice is disputed or the circumstances are unusual.

    Prompt

    Check whether this UK employee tax code appears consistent with the information supplied. Use only the documents and facts pasted below, and do not invent tax rates, allowances, dates or HMRC rules. Treat the result as a preliminary check, not professional advice.

Tax year: [tax year]
Tax code shown on the payslip: [tax code]
Tax code on the HMRC coding notice, if available: [coding notice code]
Taxable pay and tax deducted on the latest payslip: [figures]
Year-to-date taxable pay and tax deducted: [figures]
Pay frequency: [weekly, monthly or other]
Previous employment or P45 information: [details or none]
Other jobs or pensions: [details or none]
Taxable benefits or expenses: [details or none]
Marriage Allowance, pension contributions or other adjustments shown by HMRC: [details or none]
Any recent change reported to HMRC: [details or none]

Return:
1. The facts you used.
2. Any missing information that prevents a reliable check.
3. Whether the code appears consistent, inconsistent or cannot be determined.
4. A plain explanation of each discrepancy, without guessing.
5. The specific figures or documents I should compare next.
6. Whether I should contact the employer's payroll team, HMRC through GOV.UK, or a qualified payroll adviser.

Do not tell me to change the tax code myself. Do not make a definitive claim where the coding notice, payroll calculation or current GOV.UK guidance is missing.

    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 live records or know whether a recent notification has reached the payroll system.
  • AI cannot resolve conflicting information between an HMRC coding notice, payroll software and the employee's actual circumstances.
  • AI cannot take responsibility for changing a payroll record or correcting an underpayment or overpayment.
  • AI cannot reliably judge unusual cases involving multiple employments, benefits, pensions or disputed HMRC adjustments without professional review.

What caps this at PARTLY: real time truth, judgement under ambiguity and legal accountability.

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)
Output2
Inputs2
Verification1
Liability1
Effort delta1
Total7 / 10

The methodology and its thresholds are published in full.

FAQ

Can AI tell me if my tax code is wrong?
Partly. It can compare your code with your payslip, HMRC coding notice and employment details, but it cannot see HMRC's live records or take responsibility for the conclusion. Use the result as a preliminary check and ask payroll or HMRC to resolve a discrepancy.
What information do I need to check my tax code?
Gather your latest payslip, tax code notice, year-to-date pay and tax figures, P45 details, other jobs or pensions, taxable benefits and any recent changes reported to HMRC. Missing information can make a code look wrong when the issue is simply an incomplete comparison.
Can ChatGPT calculate my PAYE tax code?
It can explain the arithmetic and identify possible inconsistencies from figures you provide, but it cannot confirm the live HMRC position. This is not professional advice, and a serious or disputed case needs your employer's payroll team, HMRC or a qualified payroll adviser.
Who should I contact if my tax code is wrong?
Contact your employer's payroll team if the payslip does not match the coding notice or your employment records. Contact HMRC through GOV.UK if the coding notice itself appears wrong, and use a qualified payroll adviser or accountant for a serious or complex case.

Nearby answers

All Payroll 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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