Duplicate Invoice Detection

Topkey automatically checks each new bill against your existing bills as soon as it is added to your account. If a potential duplicate is found, you'll see a clear warning before any payment is made — protecting you from accidentally paying the same invoice twice.

How Duplicate Detection Works

When a new bill is created, Topkey runs a series of checks to find bills that may already exist in your account. A duplicate warning is triggered if any of the following conditions are met:

• Identical file upload — The uploaded invoice file exactly matches a file already on record (detected via file checksum).
• Same invoice number and amount — A bill with the same invoice number and dollar amount already exists in your account.
• Same invoice number and vendor — A bill with the same invoice number from the same vendor already exists, even if the amount differs.
• Same vendor, date, and amount — For bills without an invoice number, Topkey checks whether a bill from the same vendor, on the same date, for the same amount already exists.

Where Duplicate Warnings Appear

When Topkey detects a potential duplicate, you'll see a warning in two places:

• Bill list view — A warning indicator appears next to the bill in your bill list, so you can spot flagged bills at a glance.
• Bill detail view — A Possible Duplicate banner appears at the top of the bill, with options to review or resolve the warning.

Reviewing a Duplicate Warning

When you see a Possible Duplicate banner on a bill, you can compare it side by side with the suspected original before taking any action.

1. Open the flagged bill from your bill list.
2. Locate the Possible Duplicate banner at the top of the bill detail view.
3. Click View Original to open a side-by-side comparison of the flagged bill and the suspected duplicate.
4. Review the details of both bills — vendor, date, amount, and invoice number — to determine whether they are genuinely the same.

Dismissing a False Positive

Some vendors legitimately reuse invoice numbers (for example, a vendor who sends a monthly invoice with the same number each month). If you've reviewed both bills and confirmed they are genuinely different, you can dismiss the warning.

1. From the Possible Duplicate banner, click Mark as Not Duplicate.
2. The warning is dismissed and the bill proceeds through your normal workflow.

Deleting a Confirmed Duplicate

If you review the flagged bill and confirm it is a true duplicate, you can delete it without leaving the page.

1. From the Possible Duplicate banner on the bill detail view, click Delete Duplicate.
2. The duplicate bill is removed from your account immediately.

Frequently Asked Questions

What triggers a duplicate warning? A warning is triggered when Topkey finds an existing bill that matches on one of four combinations: identical file upload, invoice number and amount, invoice number and vendor, or vendor, date, and amount (for bills without an invoice number). Any one of these matches is enough to flag the bill.

Can vendors legitimately reuse invoice numbers? Yes. Some vendors — especially those billing on a recurring cycle — may reuse the same invoice number across multiple billing periods. If this happens, use Mark as Not Duplicate to dismiss the warning. Topkey will no longer flag that bill, and your workflow continues as normal.

How should I handle recurring bills with similar amounts? For recurring bills (such as monthly utility or subscription invoices), Topkey may flag them if they share the same vendor, date pattern, and amount. Review the bill dates carefully to confirm they cover different service periods. If they are genuinely separate bills, dismiss the warning using Mark as Not Duplicate. Adding a description or note with the specific billing period can help keep similar bills easy to distinguish.

Questions about duplicate detection? Contact Support.