Duplicate detection in Dext helps prevent the same Cost document from being processed more than once. Depending on your settings, Dext can flag or remove duplicates before they reach your accounting software.

Important:

Applies to Costs only (not Sales).
Duplicate checks run during document processing.

How duplicate detection works

Dext compares specific fields to determine whether two Cost documents are duplicates.

For receipts

Items are recognised as duplicates when all of the following match:

Supplier
Date
Total amount
Document owner (including when neither item has an owner)

For invoices and credit notes

Items are recognised as duplicates when all of the following match:

Supplier
Total amount
Document reference

If key fields (such as invoice number or date) are missing from one of the items, Dext may not recognise them as duplicates.

Duplicate detection modes

You can choose how Dext handles potential duplicates using one of three modes.

These modes can be applied:

As an account-wide default
To individual suppliers
In bulk to multiple suppliers

Important: Supplier rules override account-level settings. Learn more in Using Supplier and Customer rules

Automatic mode

Suspected duplicates are automatically deleted once detected.

Deleted duplicates do not appear in the Costs inbox.
They can only be found in the Submission history.
They can be restored if needed.

Tip: If a document “disappears” from the Processing tab, check Submission history. It may have been automatically removed as a duplicate.

Review mode

Suspected duplicates are flagged in the Costs inbox with an amber duplicate icon.

You can:

Review items side by side
Confirm whether they are duplicates
Decide how to handle them

Important: Standard users cannot review suspected duplicates, even if Review mode is enabled.

Duplicate detection off

If both Automatic and Review are disabled:

All Cost items are processed normally.
No duplicate detection takes place.

We do not recommend disabling duplicate detection, as it can lead to inaccurate records.

Using Review mode

When Review mode is enabled, suspected duplicates display an amber icon in the Costs inbox.

You can review them in two ways:

From the Costs inbox

Hover over the amber icon.
Click Review items.

From the Item details page

Click Review items in the duplicate notification box.

You’ll see the documents side by side. At the bottom of the page, choose:

If the items are not duplicates

Click No, it’s a different purchase. Both items remain in the Inbox.

If the items are duplicates

Click Yes, it’s the same purchase, then choose:

Delete image (removes the duplicate item), or
Attach image to original purchase (keeps both images attached to a single item).

Using Automatic mode

When Automatic mode is enabled, duplicates are deleted immediately after detection.

You can find them in Submission history.

Compare a deleted duplicate with the original item

Before restoring a duplicate, you may want to compare it with the original item.

Step 1: Find the duplicate

Go to Submission history at the bottom of the left-hand sidebar.
Locate the confirmed duplicate.
Click the History (page) icon.

Step 2: Copy the original Item ID

In the item history panel:

Locate the referenced original Item ID.
Copy the Item ID.

Step 3: Find the original item

Go to the Costs inbox.
Click Advanced search.
Use the Item ID filter.
Paste the Item ID.
Click Apply.

You can now compare the original item with the deleted duplicate before deciding whether to restore it.

Tip: If you can't find the item in the Inbox, try searching in the Archive.

Restore a deleted duplicate

Go to Submission history.
Locate the item marked as a duplicate.
Click Restore in the Action column.

The item will return to the Costs inbox. Restoring a duplicate does not remove or affect the original item.

Configure duplicate settings

Duplicate settings can be applied at three levels.

Important: Only Admin users can configure duplicate detection settings. Accountants/bookkeepers accessing a client account act as Admins by default.