An account can be flagged as a "test account" in the system which indicates that the account is fully provisioned, but is NOT billed (i.e. the account is not invoiced). For this reason, flagging an account as a test account is a best practice to test account creation and structuring your product catalog. If you wish to also test an account's billing, it is a best practice to set up an active account, which will be invoiced, and enter fake data (including payment information) so that there is no impact from the billing.