As of 13 August 2026, AI can only partly check whether your 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 ityou
What the alternative costsA tax adviser or HMRC can confirm the official position when the code is disputed or the circumstances are complex.
If this goes wrong: you accept an incorrect explanation and pay too much or too little tax through your wages until the record is corrected.
What to actually do
Hand it to a person
The route this page recommends
A person who owns the outcome does this end to end, worth it when the failure is dear.
Use a tool built for this
Second choiceDo it yourself
The distant thirdA chat interface, chat-fluent skill, and roughly 30 minutes until you can act on the result.
How to actually do it
- Open your latest payslip, any HMRC tax-code notice, and your HMRC Personal Tax Account, then note the tax code, taxable pay, tax deducted and pay frequency.
- Gather details of any second job or pension, taxable benefits, company car, pension contributions, taxable expenses, ceased benefits and recent change of employment.
- Remove National Insurance numbers, bank details, full addresses, passwords and other unnecessary personal data from the documents, then paste the redacted figures and wording into the prompt.
- Ask the chatbot to compare the code with the information supplied, list missing facts, and keep possible explanations separate from confirmed facts.
- Compare each explanation with the tax-code and income information displayed in your HMRC Personal Tax Account and with the latest payslip or coding notice.
- If the records disagree, contact HMRC through GOV.UK or ask your employer's payroll team to confirm which code they received and what correction is needed.
- Check the next payslip after any correction and keep the HMRC message, employer response and relevant payslips together.
Prompt
Check whether my UK PAYE tax code appears consistent with the information below. Do not guess, calculate missing figures, or state that the code is definitely correct. Explain what each part of the code means, identify any mismatch or missing information, and separate confirmed facts from possibilities. Use only the information I provide. Tell me exactly what I should check in my HMRC Personal Tax Account, payslip, coding notice and employment records. If the information is insufficient, ask only the specific questions needed. If the code may be wrong, draft a short message I can send to HMRC or my employer. This is not professional advice. Tax code: [tax code] Tax year shown: [tax year] Taxable pay so far: [amount] Tax deducted so far: [amount] Pay frequency: [weekly, fortnightly, four-weekly or monthly] Employer or pension payer: [name or description] Tax code from the previous payslip or notice: [code, if available] Benefits, taxable expenses, pension contributions or other income shown by HMRC: [details or none known] Relevant changes recently: [new job, second job, pension, benefits, ceased benefit, change of address or other change] Payslip or coding notice text: [paste redacted text here] Before analysing, list any information that is missing and could change the conclusion.
Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.
What it gets wrong
- AI cannot see your HMRC record, so it cannot know whether HMRC has included a benefit, pension or previous employment correctly.
- AI cannot confirm the official tax code sent to your employer or pension payer.
- AI cannot resolve an ambiguous tax history where several jobs, benefits or coding notices overlap.
- AI cannot take responsibility for underpaid or overpaid tax resulting from the action you take.
- AI cannot replace HMRC or a tax adviser when the records remain inconsistent after you have checked them.
What caps this at PARTLY: legal accountability, private data access and judgement under ambiguity.
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.
| Axis | Score (0–2) |
|---|---|
| Output | 2 |
| Inputs | 1 |
| Verification | 1 |
| Liability | 1 |
| Effort delta | 2 |
| Total | 7 / 10 |
The methodology and its thresholds are published in full.
FAQ
- Can ChatGPT tell me if my tax code is wrong?
- It can compare your tax code with your payslip, coding notice and the information you provide, then identify questions or possible mismatches. It cannot see your HMRC record or confirm the official position, so check the result with HMRC or your employer.
- What information do I need to check my tax code?
- Gather your latest tax code, taxable pay, tax deducted, pay frequency, coding notice and details of other jobs, pensions, taxable benefits and recent changes. Redact passwords, National Insurance numbers and bank details before sharing documents with a chatbot.
- How do I check my tax code with HMRC?
- Open your HMRC Personal Tax Account through GOV.UK and compare the code and income details there with your latest payslip and coding notice. If they do not match, contact HMRC and ask your employer or pension payer to confirm the code they received.
- Is it safe to use AI to check my tax code?
- It is suitable for organising figures and drafting questions, but it is not professional advice. Do not share unnecessary private data, and ask HMRC or a tax adviser to confirm a disputed code, a complex employment history or a case involving a large underpayment.
Nearby answers
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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