The retention policy can be setup according to your requirements whereby you can choose to set a retention and a purge period as well, in case a user/group has been deleted and you wish to automatically remove that data.

You also have the option of not using a retention policy and keeping all backup data; provided that the account's Subscription is paid and active.

Other scenarios where we'll delete backups:

1. You choose to delete an Office 365 Organisation
   
   
2. You exclude a user/group from a particular Office 365 Organisation
   
   
3. [MSP's] You delete a Customer that is set up for Office 365 Backup
   
   
4. Your Office 365 Backup Trial expires. If you do not activate this Office 365 Backup for MSPs subscription within 14 days, you will no longer be able to access the Office 365 Backup application.  Backup and restore operations will be disabled and all Office 365 mailbox backups will be permanently deleted.
   
   
5. Your Office 365 Backup payment is missed/failed. If you do not renew within 14 days, your subscription will be deactivated.
   
   Upon deactivation, your Backup and Restore operations will be disabled.  Please note that in the case of Office 365 Backup subscription your Backup Data will be permanently deleted.