As of 13 August 2026, AI can only partly calculate how much VAT your UK business owes.

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 your accounting system or spreadsheet and export all sales, purchases, credit notes and relevant adjustments for the VAT period, including dates, net amounts, VAT amounts, supplier or customer references and transaction descriptions.
   2. Write down your business's VAT scheme and any facts that affect treatment, such as zero-rated or exempt supplies, reverse-charge transactions, imports, partial exemption and capital purchases.
   3. Remove unnecessary personal information, then paste the records and business details into a chatbot using the supplied prompt, asking it to stop where a VAT treatment is unclear.
   4. Open the model's table beside the source records and match every transaction reference, net amount and VAT amount, correcting transcription errors against the original invoices and ledger.
   5. Recalculate the output VAT, recoverable input VAT, adjustments and net balance in your spreadsheet, then compare each total with the model's totals and investigate every difference.
   6. Send the reconciled calculation, supporting invoices and the list of uncertain treatments to your accountant or tax adviser before using the figure in a VAT return.

   Prompt

   Calculate the VAT my UK business owes for the period [PERIOD]. Use the transaction data below and do not invent, estimate or silently fill in any missing figures. First identify the VAT scheme, VAT rates, dates, exemptions, reverse-charge transactions, credit notes, imports, partial exemption issues and other adjustments that affect the calculation. If any treatment is unclear, stop and list the exact transaction and question that needs an accountant's decision. Separate output VAT, recoverable input VAT, adjustments and the resulting net VAT payable or repayment. Show the calculation in a clear table with transaction references and totals. Check that the totals reconcile to the source data. This is a calculation aid, not professional advice, so do not present uncertain VAT treatment as settled. Business details and assumptions: [INSERT DETAILS]. Transaction data: [PASTE DATA OR ATTACH THE SPREADSHEET].

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