As of 13 August 2026, AI can categorise your purchase invoices.

What to actually do

1. 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.

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 your current chart of accounts and bookkeeping or VAT policy, then copy the category definitions and relevant rules into a working document.
   2. Gather the purchase invoices for the period as readable PDFs or images, keeping one clear filename per invoice and removing unrelated personal documents.
   3. Record the business name, business type, VAT registration status and accounting basis in the prompt, then paste the chart of accounts and business-specific rules into the marked sections.
   4. Upload the invoices to an AI tool that can read documents, paste the prompt, and ask it to produce the requested table with separate approval and human-decision lists.
   5. Compare each proposed category, VAT treatment, amount and supplier against the original invoice and your bookkeeping rules, and resolve every flagged or low-confidence entry.
   6. Send ambiguous transactions and any entries that could materially affect VAT or the accounts to your bookkeeper or accountant before approving or importing the results.

   Prompt

   Categorise the purchase invoices I provide for a UK business. Use only information visible in the invoices and the bookkeeping rules below. Do not invent missing details, suppliers, amounts, VAT rates or business purposes.
   
   Business name: [BUSINESS NAME]
   Business type: [SOLE TRADER, LIMITED COMPANY OR OTHER]
   VAT-registered: [YES OR NO]
   Accounting basis: [CASH, ACCRUALS OR UNKNOWN]
   Chart of accounts and category definitions:
   [PASTE CHART OF ACCOUNTS]
   Business-specific rules:
   [PASTE RULES]
   
   For each invoice, return a table with: invoice filename, supplier, invoice date, invoice number, net amount, VAT amount, gross amount, currency, proposed account category, proposed VAT treatment, confidence level, and a short reason. Flag any missing, ambiguous or unusual information instead of guessing. Separate invoices that are ready for approval from invoices that need a human decision. Check that net amount plus VAT equals gross amount where the figures are present, and identify duplicates or possible credit notes. This is a bookkeeping draft, not professional advice. Do not submit anything to HMRC or post entries to accounting software.

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