how to add another email account to my Microsoft 365 family account

A Microsoft 365 Family subscription is a consumer subscription and does not use the Microsoft 365 admin center. The admin center and the “Add user” flow apply to business subscriptions only.

To have another person use Microsoft 365 with a Family subscription, share the subscription with them instead of trying to add them through an admin center:

1. Go to the Microsoft 365 Subscriptions sharing page: https://account.microsoft.com/services/office/sharing and sign in with the account that owns the Microsoft 365 Family subscription.
2. Select Share or Start sharing.
3. Choose how to share:
   • Email invite: Enter the person’s email address and select Invite.
   • Create link: Select Create link, then Copy link, and send that link via email, text, or other message.
4. The person must select Get started in the email or open the link, sign in with (or create) their Microsoft account, then select Join now to join the family group and access the subscription benefits.

If the goal is to add another email address to an existing Microsoft 365 business user (not Family), that is done in the Microsoft 365 admin center by editing the user’s aliases, but this does not apply to a Microsoft 365 Family subscription.

References:

• Share your Microsoft 365 Family or Premium subscription
• How to share your Microsoft 365 Family subscription
• Add more users and licenses
• Add email addresses