Renewing your subscription: Each product key adds 12 months of service from the existing subscription's end date. If you ...

Renewing your subscription: Each product key adds 12 months of service from the existing subscription's end date. If you enter product keys for more licenses than you currently have, the additional licenses will add users to your subscription. You cannot renew a subscription for more than 12 months.

Add licenses: Each product key provides users with 12 months of service from today. Since your existing users have an early renewal date, we have averaged the two dates (see Calculation) to make it easier to manage your subscription with a single end date for all of your users. No time is added or lost during the calculation.

Calculation:
[A (initial users) x B (time remaining on subscription) + C (new users) x (12 months) ] ÷ total number of users = new time remaining