Entry 02 · Oct 2026 · Audit & AP tool

Duplicate Invoice Detector

1. Load invoices

Drop a CSV here or click to choose Needs columns for vendor, invoice number, amount, and date

No file loaded

2. Set the rules

Invoice-number similarity to flag (%) Vendor-name similarity to treat as same vendor (%) Different invoice numbers: flag if dated within (days) Amount tolerance ($)

Invoices checked

Pairs flagged

High severity

At risk if all paid twice

Flagged pairs

Severity	Vendor	Invoice A	Invoice B	Amount	Why it was flagged

How it works

Step 1

Clean the data

Invoice numbers lose prefixes, punctuation, spaces and leading zeros, so INV-001023 and 1023 become the same. Vendor names drop case, punctuation and suffixes like Inc or LLC.

Step 2

Score similarity

Invoices are grouped by amount, then compared within each group. Edit distance counts the character changes between two invoice numbers and turns it into a 0–100% score.

Step 3

Flag with a reason

High: numbers match after cleaning. Medium: numbers are similar enough to be a typo. Low: worth a look, such as different numbers a few days apart, or sequential numbers a month apart that are probably recurring bills.