To maintain the integrity of your data, it’s a good idea to have rules in place to reduce duplicate records in the system. The customer engagement apps (Dynamics 365 Sales, Dynamics 365 Customer Service, Dynamics 365 Field Service, Dynamics 365 Marketing, and Dynamics 365 Project Service Automation), include default duplicate detection rules for accounts, contacts, and leads, but not for other types of records. If you want the system to detect duplicates for other record types, you’ll need to create a new rule.

To check for duplicates in the web application, you can use Detect Duplicates capability provided in More Commands (More commands button) on the nav bar in the grid. The duplicate records are also detected when you import data programmatically or through Import Data Wizard. In addition, you can check for duplicates by running scheduled duplicate detection jobs.