To retrieve files from your expired Microsoft 365 account, you need to be aware of the subscription lifecycle. When your subscription expires, it enters an Expired stage that lasts for 30 days (or 90 days for Volume Licensing products). During this stage, you still have access to your data and can reactivate your subscription to regain full access.
If you do not reactivate during the Expired stage, your subscription will move to a Disabled stage, which lasts for 90 days (or 30 days for Volume Licensing). In this stage, you will not be able to access your Microsoft 365 applications, but as an admin, you can still access the admin center and your customer data.
If you do not take action during the Disabled stage, your subscription will eventually be Deleted, and all customer data will be permanently lost and unrecoverable. Therefore, it is crucial to act within the timeframes provided to back up your data or reactivate your subscription.
If you are within the time limits of the Expired or Disabled stages, you can reactivate your subscription to access your files. If your account has already been deleted, unfortunately, the data cannot be recovered.
Make sure to check your admin center for options to reactivate or manage your subscription accordingly.