How to find duplicate invoices in Google Sheets

Highlight rows where the same vendor and invoice number repeat using a custom conditional formatting formula, or add a COUNTIFS column you can filter. Remove duplicates also works, but it deletes rows, so run it on a copy.

Why duplicate invoices happen

A supplier resends an invoice, or a statement repeats it.
Two people each enter the same invoice in a shared sheet.
Numbers are formatted differently, such as INV-001 and 001.

Steps

Assume vendor in column A, invoice number in column B, and data in rows 2 to 500.

Make a copy of the sheet: File, Make a copy.
Clean up spaces: select the two columns, then Data, Data cleanup, Trim whitespace. Stray spaces stop values matching.
Highlight repeats: select A2:B500, then Format, Conditional formatting. Under "Format cells if", choose "Custom formula is" and enter =COUNTIFS($A$2:$A$500,$A2,$B$2:$B$500,$B2)>1. Both cells in a repeated row now change color.
Flag repeats in a column: in C2 enter =COUNTIFS($A$2:$A$500,A2,$B$2:$B$500,B2) and fill down. Any value above 1 is a candidate.
Turn on a filter with Data, Create a filter, show values above 1 in column C, and read those rows side by side.
Optional: Data, Data cleanup, Remove duplicates. Choose the columns to compare and say whether the data has headers. Google treats values that differ only in letter case or formatting as duplicates, so check the result against your copy.

Limits of the manual method

Only spaces are cleaned. INV-0042 and 42 are still different values.
The same amount a week apart under a new number is not caught.
The same invoice under two vendor spellings, such as Acme and Acme Inc, is not caught.
Remove duplicates can delete a row you needed if you compare too few columns.

FAQ

Can I highlight just the invoice number column?

Yes, but check vendor and number together. Two vendors can both use invoice 1001, and that is not a duplicate.

How do I catch the same bill with a different number?

Add a second COUNTIFS on vendor and amount, then compare the dates. Expect some regular monthly bills to appear, so check each one against the original.

How do I save my sheet as CSV for Catchfold?

Open the tab you want, then use File, Download, and choose comma-separated values.

Check it automatically with Catchfold

Catchfold is a free tool that runs in your browser. Download your sheet as a CSV, open Your files, and pick the file. Catchfold flags bills that look like possible duplicates, or whose totals do not add up. It never leaves your computer. A person decides what to do with each finding, and Catchfold never pays, blocks or approves anything. It is a free prototype with no guarantee, and it will not catch every duplicate. The pilot guide has export steps for other tools.

Related guides

Sources

Menus and rules change; the official page is the source of truth.

Checked against official pages on 31 October 2026.