Invoices, fees, incentives, direct debits and payment reconciliation in one flow, checked before any money moves

A chain of spreadsheets that ends at the bank

Every month, the finance team downloaded supplier invoices one by one. Fees and incentives were worked out in spreadsheets, using each company’s own fee bands. Credit notes were netted off by eye. Then it was all re-typed into the accounting software.

Every step depended on the one before it, so a slip in an invoice or a rate flowed through to the posting and the debit file. The direct-debit file was the last link in that chain, and it was filled in by hand. One wrong cell could travel all the way to the bank.

None of this was difficult work. It was careful, repetitive work, done under month-end pressure, with the same figures keyed again and again between portals, spreadsheets, the bank and the accounting software. The team needed one flow that does the matching and the arithmetic, shows anything uncertain to a person, and leaves a clear record at every step.

How we worked with them

We work as forward-deployed engineers, inside the team’s workflow. We went through a full month-end with the finance team and listed every document and rule, from each company’s fee bands to how credit notes match invoices. The finance owner confirmed each rule before it went live.

Where a match is unclear, the system marks it “needs review” for a person. It never guesses. We built in short loops with AI coding agents (e.g. Claude, OpenAI), tested each change on a throwaway copy of the database, and released it only after the owner said yes.

What we built

• An invoice collector that fetches supplier invoices and their PDFs, checks each invoice’s arithmetic, and holds any invoice whose lines do not add up.
• Fees and incentives, worked out for you, from litres and agreed rates, with credit notes paired to their invoice and unpaired ones in red.
• Posting and direct debits. Set-offs are reviewed on screen and posted to the accounting software, with a sync status on every row. Debit lists fill the bank’s own template, and customers are reminded the day before.
• Owner P&L and volume dashboards, with spreadsheet export.
• A read-only MCP connector, so approved AI assistants can look up the finance data safely. Each AI assistant has its own access key: shown once, revocable at any time, and limited to the tools ticked for it. Account numbers are masked, and every call, including refused ones, is logged.

Checks before anything moves

The system is in production with the finance team, and the checks happen before anything moves. An invoice that does not add up is held, an unpaired credit note shows in red, and an unclear match waits for a person.

Every accounting post carries its own sync status, so the team can see what has reached the accounting software. The debit file follows the bank’s own template, so there is no hand-filled cell on its way to the bank.

Customers are reminded the day before each debit. The owner sees P&L and volume on dashboards, and can export them to a spreadsheet.