---
title: "Why does a bill say Possible duplicate?"
description: "Cleo Pay checks each new bill against bills you already entered and flags it as a Possible duplicate when the invoice number, vendor or amount match. Open the bill to see what it matched, then mark it Not a duplicate or cancel it."
url: https://cleo-pay.com/help/duplicate-bill-warnings
category: "Bills and approvals"
audience: [business]
updated: 2026-10-22
support: support@cleo-pay.com
---

# Why does a bill say Possible duplicate?

> Cleo Pay checks each new bill against bills you already entered and flags it as a Possible duplicate when the invoice number, vendor or amount match. Open the bill to see what it matched, then mark it Not a duplicate or cancel it.

Cleo Pay checks every new bill against the bills you've already entered. If it looks like one of them, the bill is marked **Possible duplicate**. Open the bill to see which bill it matched and why. If it's a real duplicate, cancel or decline it. If it isn't, click **Not a duplicate** and the warning goes away.

## Where you see the warning

- In your bills list, a "Possible duplicate" badge or an amber warning icon next to the invoice number.
- At the top of the bill itself, a "Possible duplicate" box that lists each matching bill, its amount and the reason.
- When you pay, a "Possible Duplicate" screen that asks you to confirm before the money goes out.

The check runs right after a bill is added. Until it finishes, the bill shows "Checking…" or "Still checking for duplicates…".

## What counts as a match

Each matching bill shows one reason:

| Reason you see | What matched |
|---|---|
| Same vendor & invoice # | Same vendor and the same invoice number |
| Same invoice # & amount, different vendor | Same invoice number and amount, but a different vendor |
| Same vendor & amount, dated a few days apart | Same vendor and amount, with invoice dates or due dates within 14 days of each other |
| Same invoice # (different vendor) | Same invoice number, a different vendor and a different amount |

Invoice numbers are compared without caring about capital letters or leading zeros, so INV-0042 and inv-42 count as the same number. Two bills from the same vendor with different invoice numbers aren't flagged for having the same amount.

Only bills from the last 12 months are compared. Cancelled and declined bills are left out. When an invoice is sent twice, only the second copy gets the warning. The first one stays clean.

## What to do

1. Open the flagged bill.
2. In the "Possible duplicate" box, click **Open** next to a match to look at the other bill in a new tab.
3. If it's the same invoice, cancel or decline the bill you don't need.
4. If it's a different invoice, click **Not a duplicate**. You can add a note, like a different PO number. Then click **Confirm not a duplicate**.

The bill's activity log records "Marked not a duplicate". Once you clear a match, it won't stop you from paying.

## Paying a flagged bill

You can still pay a bill that's flagged. When you click pay, Cleo Pay shows "This invoice looks like a duplicate" with the matches. Tick "I reviewed the possible duplicate and want to pay" and click **Pay anyway**, or click **Go back**.

When you pay several bills at once, the review screen tells you how many look like possible duplicates. Tick the box that says you reviewed them before you pay. If the check couldn't run, you'll see "We couldn't check these invoices for duplicates." and can choose **Pay without the duplicate check**.

## If it doesn't work

If a bill says "Couldn't check for duplicates." or keeps getting flagged after you cleared it, email support@cleo-pay.com with the vendor name and the invoice numbers of both bills.