As of 13 August 2026, AI can only partly correct a mistake on your UK VAT return.

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 relevant VAT returns, bookkeeping report, sales and purchase invoices, credit notes and bank records for the affected VAT period.
   2. Remove unnecessary personal data, then paste the records and a plain description of the suspected error into the prompt.
   3. Ask the model to produce a transaction-level schedule showing the original figure, corrected figure, VAT amount and affected VAT return box.
   4. Compare every calculated total with the source invoices, credit notes and bookkeeping entries, and correct any mismatch in the schedule.
   5. Open the current VAT error-correction guidance on GOV.UK and compare its correction route, limits and notification requirements with the model's checklist.
   6. Send the schedule, source evidence and any unresolved treatment questions to a VAT accountant before changing a submitted return or contacting HMRC.
   7. Make the correction or disclosure only through the appropriate HMRC process after the VAT accountant has confirmed the route and figures.

   Prompt

   Help me prepare to correct a mistake on a UK VAT return, but do not file anything, make a final tax judgement or present uncertain treatment as fact. Use only the records and current GOV.UK guidance I provide or ask me to check; do not rely on memory for thresholds, deadlines or correction routes. First identify the affected VAT period, return boxes, transactions, VAT rates, net amounts and VAT amounts. Recalculate the figures and show the arithmetic. Then separate clear arithmetic or data-entry errors from questions that need a VAT accountant or HMRC. For each uncertain point, explain what fact is missing and give the exact GOV.UK search or guidance topic I should check. Produce: a transaction-level correction schedule, the proposed changes to each VAT return box, a list of evidence to retain, questions for a VAT accountant, and a final checklist before I submit or disclose anything. Do not invent figures, invoices, dates, VAT rates, thresholds or explanations. Here are the records and my description of the error: [paste records and description].

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