How to find duplicate bills in QuickBooks Online

Two things help: switch on the setting that warns you when a bill number is reused for a vendor, and export your bills to a spreadsheet to sort and compare them. Neither is perfect, but together they catch the obvious repeats.

Why duplicate bills happen

A supplier emails the same invoice twice, or sends a reminder that looks like a new bill.
Two people enter it, or one person enters it from the email and again from the paper copy.
The number is typed differently: INV-001 the first time, 001 the second.

Steps

Turn on the warning. Replies on Intuit's support site say to open the gear icon, choose Account and settings, go to Advanced, and look under Other preferences for the option that warns about a duplicate bill number. The label differs between versions. Save it.
From then on, QuickBooks should warn you when you enter a bill number already used for the same vendor. It does not recheck bills you entered earlier.
To review existing bills, open Reports and run a report that lists your bills or vendor transactions. Pick one that shows vendor, number, date and amount.
Use the export option on the report and choose Export as CSV (or Export to Excel). If Excel shows a file that looks incomplete, click Enable Editing.
In the spreadsheet, sort by vendor, then by amount. Look for neighbours with the same vendor and amount, or the same number.

Limits of the manual method

The warning only matches the number as typed, per vendor. INV-0042 and 42 look different to it.
It does nothing for bills entered before you turned it on.
A repeat with a new number, or the same amount a week apart, only shows if you sort and read carefully.
On a long list, it is easy to miss one.

FAQ

Does QuickBooks Online stop me saving a duplicate bill?

The setting is described as a warning. Treat it as a prompt to check, not a block.

Should I delete a bill I think is a duplicate?

Check the original PDF or paper copy first. Two similar bills can both be real, such as monthly charges for the same amount.

Does the warning cover the same invoice entered under two vendors?

Replies describe the check as per vendor, so a repeat under a different vendor name would not trigger it.

Check it automatically with Catchfold

Catchfold is a free tool that runs in your browser. Export your bills as a CSV, open Your files, and pick the file. It never leaves your computer. Catchfold flags bills that look like possible duplicates, or whose totals do not add up, and a person decides what to do. It 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

Intuit support community: bill number already used (a community thread on Intuit's site, not a formal help article)
Run reports in QuickBooks Online
Export reports to Excel in QuickBooks Online

Menus change; the vendor's help page is the source of truth.

Checked against vendor pages on 23 October 2026.