Your husband must share the Microsoft 365 Family subscription with your existing Hotmail/Outlook Microsoft account; accept that invitation using the same account so your mailbox remains intact and receives the shared subscription benefits.
Add your existing account to the Family subscription
- Your husband signs in as the subscription owner at the Microsoft 365 Services & subscriptions sharing page:
https://account.microsoft.com/services/office/sharing
- Select Share or Start sharing.
- Select Email invite.
- Enter your existing Hotmail/Outlook email address—the address connected to your current Microsoft 365 Personal subscription—and select Invite.
- Open the invitation while signed in with that same Hotmail/Outlook account.
- Select Accept or Get started, followed by Join now. The invitation must be accepted within 48 hours. [^1^](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID] "Share your Microsoft 365 subscription | Microsoft Support")
- After acceptance, check your Microsoft account’s Services & subscriptions page. It should show that Microsoft 365 is being shared with you.
Do not create another Microsoft account or try to move the Hotmail address into your husband’s account. Two existing Microsoft accounts cannot be merged, and an existing Outlook.com address cannot be attached to another existing Microsoft account. ^2^
Your email, contacts, OneDrive files, and other personal information remain under your account and are not exposed to the subscription owner or other family members. [^3^](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID] "Microsoft 365 subscription sharing FAQs")
About the expiration and storage warning
The warning appears because your current Personal subscription is approaching expiration and the account is being evaluated against the free storage allowance. When a subscription expires:
Once the paid Family benefit is active on your existing account, Outlook.com provides a 100 GB mailbox per person; the increased allowance may take a short time to appear. Outlook.com email storage and Microsoft cloud storage are separate quotas, although Outlook.com attachments also count toward cloud storage. ^5^
To identify which quota generated the warning, open Outlook.com and go to:
Settings → Account → Storage
Check both mailbox usage and Microsoft cloud/OneDrive usage. Being within the email mailbox limit does not necessarily mean the cloud-storage quota is also within its limit.
If the invitation cannot be accepted
- “Already in another family group”: leave that other Microsoft family group first, then have your husband resend the invitation. A person can receive shared benefits only while in the subscription owner’s family group. [^1^](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID] "Share your Microsoft 365 subscription | Microsoft Support")
- No Share/Start sharing button: verify that your husband signed in with the Microsoft account that actually owns the Family subscription. Someone receiving a shared subscription cannot share it again.
- Invitation expired: your husband can find your pending entry on the sharing page and select Resend invite.
- Storage warning remains after Family appears on your account: allow time for the paid allowance to update, then recheck Settings → Account → Storage. If the mailbox itself exceeds 100 GB, joining Family will not raise it further; storage must be reduced. ^5^
There is no need to change your Hotmail address, migrate your mailbox, or reinstall Office merely to move from one Microsoft 365 home subscription to another.
References
- [Share your Microsoft 365 subscription | Microsoft Support](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID])
- How to link outlook.com email to 365 subscription - Microsoft Q&A
- [Microsoft 365 subscription sharing FAQs](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID])
- [What happens when your Microsoft 365 subscription expires | Microsoft Support](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID])
- Storage limits in Outlook.com | Microsoft Support