Contacts Manager
View, clean up and de-duplicate your Microsoft 365 contacts. Changes sync to your phone and Outlook.
Your contacts go straight between this browser and Microsoft 365. Backups stay on your PC. This app stores nothing online. Help · Privacy · Set up for your organisation
A shared mobile number or email marks a likely duplicate. A shared work, home or fax number only counts when the names also fit (e.g. "Alice T" and "Alice Test"), so colleagues on one switchboard aren't listed. A mobile or email used by three or more different people (e.g. info@company) is treated as a shared company value.
Exact = same name and a shared phone number or email. In each group, untick contacts that aren't the same person: Merge ticked combines only the ticked ones into the one marked Keep (you preview first), and Not duplicates (ticked) takes the ticked ones out of the group for good (tick all to dismiss the whole group). Merged-away contacts go to Deleted Items.
Everything changed in this session. It's also saved inside every backup made after the change.