Automating invoice processing without buying new software

Every invoice that lands in your inbox has to be opened, read and typed somewhere. Supplier, invoice number, date, due date, net, tax, total, sometimes line items.

Each one only takes a few minutes. The trouble is they never stop, and the person doing it usually has better things to do. Then come the typos: a transposed digit, a duplicate entered twice, a missed due date. None of it is dramatic on the day. It all shows up at month end, when someone has to find it.

The shape of it

When I build one of these, it nearly always looks the same:

1. Watch the place invoices arrive: a shared inbox, a Google Drive or OneDrive folder, or a supplier portal.
2. When a new invoice comes in, AI reads the PDF or photo and finds the fields you care about.
3. Run checks: does the total add up, is the supplier known, has this invoice number been seen before, is the tax sensible?
4. If everything passes, save the data to your sheet or accounting software and file the original.
5. If something fails, flag it for a person with a clear note on what looked wrong.

The AI part is reading the document. Everything around it is plain, predictable rules. That mix is what makes it reliable.

Why AI changed this

Older tools needed a template for every supplier layout and broke the moment a supplier redesigned their invoice. AI reads a document more like a person does. It understands that "Amount due", "Total payable" and "Balance" are probably the same thing, even in different corners of the page.

It isn't perfect. Blurry phone photos and handwriting are harder, which is exactly why the checks and the human review step exist.

What gets flagged

Anything unusual goes to a person instead of being guessed:

• a supplier you've never paid before
• line items that don't add up to the total
• an invoice number that looks like a duplicate
• a missing field, like no due date or no tax number
• an amount well above what that supplier normally charges

Someone approves or fixes those with a click, and the rest flows through. The automation does the typing. You still decide what gets paid.

A typical week

A small online shop gets around 40 supplier and order emails a day, most with a PDF attached. Today someone types each one into a Google Sheet and later re-types it into the accounting software.

With the automation, each PDF is read as it arrives, the row appears in the sheet, the bill is drafted in the accounting software, and the PDF is filed in a folder by supplier and month. On a typical day a handful get flagged, maybe a new supplier or a total that doesn't match the line items. Someone checks those in a few minutes instead of typing all 40.

The same pattern works for orders, delivery notes, receipts and purchase orders. If it's a document with numbers that someone types up, it's a candidate.

No new software needed

This connects what you already have: Gmail or Outlook, Google Sheets or Excel, cloud storage and your accounting software. If your accounting tool has no direct way in, the data goes to a spreadsheet you import from.

One tip before anything else: collect 20 or 30 real invoices from different suppliers, including the messy ones, and test on those. It tells you far more than any demo.

And if you get three invoices a month, don't bother yet. This pays off when someone is typing them up every week.

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Originally published on dizilus.com.