Alert data storage oversized (250 Gb) even if I have 1Tb available

This usually means that the affected OneDrive account is still being treated as a 5 GB account instead of the 1 TB Family allocation, or the storage status has not refreshed yet.

For Microsoft 365 Family, each shared person gets their own separate 1 TB quota. Storage is not pooled across the 5 people. If one account still shows over-capacity at 250 GB, check this in order:

1. Verify the Microsoft 365 Family invitation was accepted for that specific Microsoft account.
2. Wait up to 2 hours after accepting the invitation, then open Manage storage, refresh the page, and check whether the 1 TB quota appears.
3. Confirm the OneDrive app and the Microsoft 365 Family subscription are using the same Microsoft account.
4. Check the account dashboard Microsoft storage area to confirm the quota shown for that account.
5. If the OneDrive app is signed in with a different account, unlink that PC and sign in again with the account that has the Family storage benefit.
6. If the web account already shows 1 TB but OneDrive still reports over capacity, wait up to 24 hours and then unlink/relink OneDrive to force a refresh.

Relevant points for this scenario:

• A Microsoft 365 Family subscriber and up to five other people each get 1 TB of OneDrive storage.
• If OneDrive is over quota, files become read-only and new uploads, edits, and sync stop.
• If a shared Family account remains at 5 GB, the most common causes are that the invitation was not fully accepted or the storage update has not propagated yet.

• Troubleshoot sharing a Microsoft 365 subscription
• Microsoft storage quotas
• My OneDrive says it's full
• What is Microsoft cloud storage?
• Microsoft 365 is not backing up to my 1tb storage. - Microsoft Q&A
• OneDrive says I am out of space. I am not. - Microsoft Q&A