Hello,

In Microsoft CRM 4.0 when you import data using the data import wizard there is a checkbox in the wizard that says: "Enrich data by updating existing records rather than creating new records", I think this feature benefits from the data duplicate rules to see whether the record exists or not then it will update the existing one if exists.

In Dynamics 365 online there is no such option. Instead, the user need to Export existing data then reimport etc... so that the second imported file will contain the GUIDS and based on that it will update.

My suggestion is to implement a similar checkbox as the one explained above that was available in CRM 4.0. This way is easier and more convenient than exporting and importing.

Thank you.