When you select the Flexible Plan for Google Apps billing, you're billed monthly for the number of user accounts you use that month. In US dollars, for example, you're billed $5 per user for Google Apps for Work or $10 per user for Google Apps Unlimited.
With the Flexible Plan, you can add or delete user accounts at any time and your monthly rate goes up or down accordingly. The Flexible Plan is therefore ideal for businesses with a variable-size workforce. For example, a vacation resort might add temporary workers during the Summer while retaining a smaller staff the rest of the year. The Flexible Plan lets those companies provide their temporary employees with Google Apps and only pay for the service while it's used. User accounts can be deleted when employees leave at the end of the summer.
How payments are calculated
You are billed for the service you use at the beginning of the following month. For example, if you purchase the Flexible Plan with 7 user accounts in US dollars, you're billed $35 (7 users X $5 per user) at the beginning of the following month. If you keep using only 7 accounts, you continue to be billed $35 each subsequent month, until you cancel your subscription.
If you add or remove users during any month, we prorate your payments. If you add a user on April 1 and delete them on April 15, we charge you for only half a month of service.
Canceling your service
With the Flexible Plan, you can cancel your subscription whenever you want, and you'll only pay for the service you've already used.