Duplicate detection
A warning dialog on save that lists existing rows matching a published duplicate detection rule, so users can stop or continue.
What it is
When a user saves a new row, or changes a column used by a rule, Dataverse can compare it to existing rows. If it finds a match, the form opens a Duplicate records found dialog that lists the matching rows. The user can open a match, cancel the save, or choose Ignore and save to continue.
When to use it
Use it to stop duplicate customers, contacts or leads from getting in by hand entry. It is not a constraint: users can still ignore it, and rows from flows, imports and code do not show the dialog. For hard rules, use alternate keys or Field validation. For clean-up of existing data, run duplicate detection jobs.
Licensing and configuration
No extra licence. An administrator or system customizer creates rules in the Power Platform admin center (the Duplicate detection rules page of the environment settings), sets the criteria, such as exact match on Account Name, then selects Publish. Duplicate detection must be turned on for the organisation. Microsoft's limit is five published rules per table at one time, and publishing is asynchronous.
Pitfalls
- A rule does nothing until it is published, and publishing can take a while on large tables.
- The dialog appears only for rows created or updated in the user interface. Workflows, flows and imports do not trigger it.
- Rules compare match codes, so two rows created at the same moment can both be saved.
- Raising the length of a column used in a rule after publishing can hide duplicates.
Try it in the demo
- Open a new account at the deep link.
- Type Wayne Enterprises as the Account Name and select Save.
- Read the matches in the Duplicate records found dialog, then select Ignore and save to create the row anyway.