Admin > Billing shows your plan, how many hours you've used this period, and your invoices.
Before you start
An admin role.
The Billing screen
Your plan and its status.
The current billing period, and when a trial ends.
The monthly price, the hours included, and the overage rate for hours beyond them.
Your payment method. Click Manage to change it.
Change Plan and Cancel Subscription.
Days left in this period, and how much of your hours you've used.
Used, Included, Remaining and Active Sessions.
Projected overage, if you carry on at the current rate.
Invoices: each with its date, amount and status.
NOTE: Active Sessions is the number to watch. If it's higher than the number of people working, a session has been left open and is using hours. See Control what you spend.
Rollover
Hours you don't use carry forward into later periods. When you have rollover hours, the usage card shows them.
Overage
Hours used beyond your included and rollover hours are billed at the overage rate. To cap it, set Billing Overage Limit in Admin > Account Settings > General Settings:
Empty: no limit.
A number: the most overage hours allowed each billing period.
0: no overage. The account stops rather than spends.
When to change plan
Larger plans buy hours more cheaply than overage does. If you pay overage most months, compare the next plan up and click Change Plan.