Subscription License is a paid and fully-functional license that expires at the end of the subscription term which is 1–5 years from the contract start date (depending on the subscription length).
A grace period of 1 month is granted after the expiration of license for purpose of renewal. During this period, the program functionality is not limited. After this period, processing of all user accounts in all organizations will be stopped; scheduled jobs will be terminated with failure. In both cases, a notification message will be shown to notify you that the license is either about to be expired or has expired.
The restore abilities will continue to function regardless of whether your license has expired or not.
Additional processing of no more than 10 user accounts or 10% of the license count (whichever is greater) is granted if you exceed the license limit by up to 10 user accounts or up to 10% of the license count.
If you exceed the license by more than 10 user accounts or more than 10% of the license count (whichever is greater), Veeam Backup for Microsoft Office 365 allows you to process these 10 (or 10%) extra user accounts according to the FIFO queue logic (that is, "first in — first out"); no additional accounts are allowed.
The grace period in this case is not limited and lasts during the whole term of the subscription.