As of 13 August 2026, AI cannot check your VAT return before submission.

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 gets you a draft, but you cannot verify it yourself. That is the catch.

   How to actually do it

   1. Open your accounting software and export the VAT return report, sales VAT report, purchase VAT report and adjustment report for the same VAT period.
   2. Gather the VAT scheme, the return period, any previous-period corrections, reverse-charge entries and invoices for unusual or high-value transactions.
   3. Remove unnecessary personal data, then paste the reports and explanations into the prompt and attach the spreadsheets if the chatbot supports file uploads.
   4. Ask the model to produce a box-by-box reconciliation showing the source totals, the return figures and every difference.
   5. Compare each flagged arithmetic or duplicate-entry issue against the original invoice, ledger entry and VAT report, and correct only errors you can evidence in your accounting records.
   6. Give unresolved VAT-treatment questions and the reconciliation to your accountant or VAT adviser, ask them to approve the figures, and submit the return only after their review.

   Prompt

   Check the VAT return information below as a bookkeeping and reconciliation exercise, not as a replacement for an accountant or VAT adviser. Use only the information I provide and do not invent figures, transactions, VAT rates, dates or explanations. First reconcile the output VAT, input VAT, reverse-charge amounts, net VAT and any other boxes against the supplied sales ledger, purchase ledger, VAT reports and previous-period adjustments. Then list every mismatch, duplicate, missing entry, unusual amount or calculation error, showing the source figures and the arithmetic. Separate mechanical errors from questions about VAT treatment. For each VAT-treatment question, explain what fact is missing and point me to the relevant current GOV.UK or HMRC guidance to check, without deciding that the treatment is correct. State clearly which checks you could not perform. End with a short list of questions for an accountant or VAT adviser before submission. Do not tell me to submit the return unless every unresolved issue has been reviewed by a qualified professional.
   
   VAT scheme: [standard, cash accounting, flat rate or other]
   VAT return period: [period]
   VAT return figures by box: [paste figures]
   Sales VAT report: [paste or attach]
   Purchase VAT report: [paste or attach]
   Reverse-charge and other adjustments: [paste details]
   Previous-period corrections or carried-forward amounts: [paste details]
   Relevant transaction samples and invoices: [paste or attach]
   Business notes about unusual transactions: [paste details]

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