How do I find duplicate invoices in Excel?

Use COUNTIFS. Flag rows where the vendor and invoice number appear more than once, run the same check on a cleaned-up invoice number (no prefixes, dashes or leading zeros), and flag the same vendor with the same total within about 7 days.

Can a duplicate invoice have a different invoice number?

Yes. Re-issued or corrected invoices often get a new number. Compare vendor, total, date and line items, not just the number.

Should I pay from a vendor statement?

Generally pay from invoices and use statements to reconcile: confirm you have every invoice and that your payments were applied. Paying from both is a common way to pay twice.

PaperChore › Guides › Invoices

How to catch duplicate invoices before you pay them twice

By the PaperChore team · Updated Oct 15, 2026

The short answer

Check every new invoice against what you've already recorded on four things: the same vendor and invoice number; the same number after stripping prefixes, spaces and leading zeros (INV-01043 vs 1043); the same vendor and total within a few days; and the same lines and total under a new number (a re-issued invoice). Pay from invoices, not statements, and mark each one paid.

How duplicates sneak in

The vendor emails a PDF and the driver hands over a paper copy.
A "reminder" or "past due" copy arrives and looks like a new bill.
You pay from a monthly statement and also from the individual invoices on it.
The invoice is corrected and re-issued with a new number, and the original isn't voided.
Two people handle bills (or two inboxes get them).

Four checks, in a spreadsheet

Assume an Invoices table with Vendor in A, Invoice number in B, Date in C and Total in D.

Exact match. =COUNTIFS(A:A,A2,B:B,B2)>1 flags the same vendor and number twice.
Normalized number. Add a helper column that strips common prefixes, punctuation and leading zeros, for example =IFERROR(VALUE(SUBSTITUTE(SUBSTITUTE(UPPER(B2),"INV",""),"-","")),UPPER(B2)), then run the same COUNTIFS on the helper. Adjust it to your vendors' formats.
Same vendor, same total, close dates. =COUNTIFS(A:A,A2,D:D,D2,C:C,">="&C2-7,C:C,"<="&C2+7)>1 catches re-sent bills with a different or missing number. Some will be legitimate (a standing weekly order), so treat these as "look", not "delete".
Re-issued invoices. If you keep line items, compare the set of items and quantities for invoices from the same vendor with the same total. Identical lines under a new number usually mean a replacement. Pay one and ask the vendor to confirm the other is void.

Habits that prevent most of it

One intake point. One email address or folder for all bills, and one person (or a clear rule) for entering them.
Pay invoices, reconcile statements. Use the vendor's statement to check that you have every invoice and that your payments were applied, not as something to pay.
Mark paid immediately, with the payment date and method, in the same row.
Keep the original file name on each row so anyone can open the source in seconds.
Ask for credits in writing and record credit memos as their own rows with negative totals.

Already paid twice?

Email the vendor with both invoice numbers, dates, amounts and proof of both payments, and ask for a refund or a credit on your account. Most vendors will fix a clear double payment quickly when you show both.

Common questions

How do I find duplicate invoices in Excel?: Use COUNTIFS. Flag rows where the vendor and invoice number appear more than once, run the same check on a cleaned-up invoice number (no prefixes, dashes or leading zeros), and flag the same vendor with the same total within about 7 days.
Can a duplicate invoice have a different invoice number?: Yes. Re-issued or corrected invoices often get a new number. Compare vendor, total, date and line items, not just the number.
Should I pay from a vendor statement?: Generally pay from invoices and use statements to reconcile: confirm you have every invoice and that your payments were applied. Paying from both is a common way to pay twice.

Want it done for you? TallyThis runs these duplicate checks on every batch: exact and cleaned-up invoice numbers, the same vendor and total on nearby dates, and matching line items. It flags them for you to review rather than deleting anything.

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