As of 13 August 2026, AI can allocate part-payments to your invoices.

What to actually do

1. Use a tool built for this

   The route this page recommends

2. Do it yourself

   Second choice

   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 invoice ledger and export the open invoices, including invoice number, customer, invoice date, original amount, amount already paid, outstanding balance and credit notes.
   2. Open your business bank transaction list and export the relevant incoming payments, including payment date, bank reference, payer or customer and amount.
   3. Gather customer remittance advice, emails and agreed allocation rules, then remove unrelated messages and redact unnecessary personal data.
   4. Paste the invoice data, payment data and allocation rules into the prompt, keeping the column headings and dates clear.
   5. Ask the chatbot to produce the allocation table, manual-review list and arithmetic checks specified in the prompt.
   6. Compare every proposed allocation with the bank transaction, customer account and invoice ledger, and recalculate the remaining payment and invoice balances.
   7. Enter only verified allocations into your bookkeeping system, leave unclear payments unapplied, and send the manual-review list to your bookkeeper or accountant where the records affect a serious dispute or filing.

   Prompt

   Allocate the payments in the payment table to the invoices in the invoice table.
   
   Use these rules:
   1. Match by customer, payment reference, invoice number, amount and date where available.
   2. A payment may be allocated across multiple invoices.
   3. Do not invent an invoice number, customer, payment or allocation.
   4. Do not force a match when the evidence is unclear.
   5. Keep unapplied amounts, overpayments, underpayments, credit notes and disputed items separate.
   6. Never allocate more to an invoice than its outstanding balance.
   
   Return a table with these columns: payment date, payment reference, customer, payment amount, invoice number, amount allocated, remaining payment amount, invoice balance after allocation, match confidence, and reason.
   
   Then provide:
   - a list of payments needing manual review, with the exact ambiguity;
   - a list of invoices still partly or wholly unpaid;
   - a check that total allocated amounts plus unapplied amounts equal total payments;
   - a check that no invoice has been allocated above its outstanding balance.
   
   Use only the data supplied below. Do not give tax or accounting advice. Treat dates as UK dates in the format DD/MM/YYYY.
   
   INVOICES:
   [Paste invoice number, customer, invoice date, due date, original amount, amount already paid, outstanding balance, and credit notes here]
   
   PAYMENTS:
   [Paste payment date, bank reference, payer or customer, payment amount, and currency here]
   
   ALLOCATION RULES OR CUSTOMER REMITTANCES:
   [Paste any agreed rules or remittance advice here]

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

3. Hand it to a person

   The distant third

   A person who owns the outcome does this end to end, worth it when the failure is dear.