Microsoft does not provide a way through support content to identify the other person or disclose their device details directly for a Minecraft username change.
What can be checked:
- Open the Microsoft account Recent activity page: See your recent activity
- Review entries from the last 30 days.
- Expand any suspicious activity to see available details, which can include:
- IP address
- approximate location
- device or operating system type
- browser or app type
- If an item appears under Unusual activity, use This was me or This wasn't me.
- If the activity was not authorized, immediately change the password and update security settings.
Important limits:
- The activity page shows Microsoft account sign-in and security-related activity, not a dedicated Minecraft username-change audit log.
- Microsoft does not show all account activity; it usually shows significant security events.
- Location can be inaccurate, especially on mobile networks.
If the username change happened because the Microsoft account was accessed by someone else, the safest next steps are:
- Change the password.
- Update security info.
- Review recent sign-in activity.
- Enable two-step verification.