How to use the Duplicate Invoice Detector
- Paste invoices as vendor, invoice no, date, amount.
- Set the window for same-amount matches.
- Review the flagged pairs and export them as CSV.
How it works
Invoices from the same vendor are compared in pairs. Invoice numbers are cleaned (case, punctuation and leading zeros ignored). It flags exact repeats, the same number with a different amount, numbers that differ by one character, and the same amount within your chosen number of days.
Worked example
INV-1001 appearing twice at 12,500 is flagged High. "0045" and "45" from the same vendor with amounts 4,300 and 4,350 is flagged Medium.
Limits and good to know
A flag is a prompt to check, not proof of a duplicate. Legitimate recurring charges can look similar.
Frequently asked questions
No. Only invoices from the same vendor are compared.
Yes. It is free with no sign-up.
No. Your data is processed in your browser and is not sent to a server.