How we automated invoice and receipt filing

The problem

Every business purchase needs its invoice or receipt in the accounts, with the VAT recorded correctly. Each one is a small job: spot the transaction, find the email with the PDF (or log in to the supplier’s website to download it), check the VAT, attach it and explain the transaction.

Small, but it never ends, and anything skipped piles up until the VAT return is due.

Our first version, and why it wasn’t enough

The first version started from the inbox. Emails with invoices got a Gmail label, an n8n workflow checked for them every 30 minutes, saved the PDF to Dropbox and relabelled the email as done. There was no AI involved.

It worked when the email had a PDF attached. It fell over when it didn’t: invoices you have to download from a supplier’s account, emails with only a link, receipts that never arrive by email at all. And because it started from the inbox, it couldn’t tell us which payments were still missing their paperwork.

What we built instead

The new version starts from the bank, not the inbox. Every payment that goes out is something that needs a document, so that’s the list it works through.

1. It checks the bank transactions in FreeAgent and picks out the ones that need an invoice or receipt.
2. It looks for the document in our email. Our inbox assistant already labels invoices and receipts as they arrive, which gives it a head start.
3. If the PDF isn’t in the inbox, it gives us a link to the supplier’s site and instructions for getting it, so fetching it takes seconds. No more trying to remember where a supplier (cough, cough, Amazon) hides its invoices on its website.
4. It works out the VAT. Simple rules handle the straightforward cases. When the rules can’t, AI reads the document and works it out.
5. It scores how confident it is. If it’s sure enough, it posts the transaction in FreeAgent automatically. If not, it asks us.
6. It shows everything on a dashboard: what’s been posted, what’s waiting for a check, and what’s still missing a document.

Why the confidence score matters

Accounts have to be right. A system that’s right most of the time but posts its mistakes quietly is worse than no system at all, because you stop checking. So it only acts on its own when it’s sure, and everything else comes to a person. It also learns about each supplier over time, so more and more transactions clear on their own.

What it saves

We haven’t measured it, so we won’t give you a number. But I can tell you it was the job I hated most. If you don’t believe me, just ask my accountant.

The main difference is that the work no longer builds up before a VAT return: most transactions are filed without anyone touching them, and the dashboard shows exactly which few need us.

Could this work for you?

If you spend time each month matching receipts to bank payments, yes. We built ours on FreeAgent, but the same approach works with other accounting software that has a bank feed and an API, such as Xero or QuickBooks.

A version for your business would be set up around your suppliers, the way you categorise spending and how cautious you want it to be before it posts anything by itself.