I believe my wife and I both have subscriptions instead of sharing one, how do I fix that?

To move from two separate Microsoft 365 home subscriptions to sharing a single one, the steps are:

1. Decide which subscription to keep
   • Sign in to each Microsoft account at https://account.microsoft.com/services and identify which account has the Microsoft 365 Family (or Premium) subscription that should be shared.
   • The other subscription can later be cancelled; cancelling a subscription does not delete the Microsoft account or its email address.
2. Share the chosen Microsoft 365 Family subscription
   • Using the subscription owner’s account (the one to keep), go to the Microsoft account Sharing page: https://account.microsoft.com/services/office/sharing.
   • On the Sharing tab, select Start sharing.
   • In the Share Office dialog, choose one of:
     • Invite via email: Enter the other person’s email address and select Invite. They must accept using that same email address.
     • Invite via link: Select Copy and send the link by email, text, or other message. When they click the link and sign in with their Microsoft account, they are added to the subscription.
   • A Microsoft 365 Family subscription can be shared with up to five other people.
3. Ensure the invite is accepted correctly
   • The invited person must click Accept in the email or link and complete the steps to join.
   • If the invitee is already in another Microsoft family group, they must leave that group before joining the subscription owner’s family group; otherwise sharing will not work.
4. Cancel the extra subscription
   • Sign in to the Microsoft account that has the subscription that should be stopped.
   • Go to Subscriptions, select Manage for that Microsoft 365 subscription, and cancel it. The Microsoft account and email remain; only the paid subscription ends.

After this, both accounts can keep their own email addresses, but only one Microsoft 365 Family subscription is billed, and its benefits are shared.

References:

• Troubleshoot sharing a Microsoft 365 subscription
• Share your Microsoft 365 Family or Premium subscription
• How to share your Microsoft 365 Family subscription
• Switch between Microsoft 365 subscriptions
• I am paying for two subscriptions - Microsoft Q&A
• how to download microsoft office 365 from subscription with multiple installs - Microsoft Q&A
• How to resolve being billed on 2 separate charge accounts for the same thing - Microsoft Q&A