Turn supplier invoice emails into a spreadsheet, with the sums checked before anything is saved
A consultant who builds workflows for small UK businesses shared a free n8n template. It only watches one Gmail label for supplier invoices, has an AI model read each PDF into fixed fields like supplier, dates, net, VAT and total, then checks the math in plain code: net plus VAT has to match the total and the line items have to add up. Invoices that pass go into a Google Sheet, and anything that fails lands on an Exceptions tab with the reason, so a person takes a look. She notes it can't read scanned invoices and doesn't catch duplicates yet.
Where this comes from
Original post by jessymariau on n8n Community, Oct 19, 2026. We rewrote it in our own words. The result is what the poster reports.
Read the originalCopy-paste setup
Read the invoice text below and return only these fields: supplier, invoice number, invoice date, due date, currency, net amount, VAT amount, total and line items (description, quantity, amount). If a field is not in the text, leave it empty. Do not guess, and do not calculate or fix any numbers.
Our own instructions for the AI step that reads the PDF text, written from what the source describes. The sums are checked in a separate code step, not by the AI. We have not tested it yet. Text in [BRACKETS] is what you replace.