In your organization, you navigate to Directory > Managed accounts, and you see the following:What...

The table is showing the total number of managed accounts in the organization and the number of deactivated accounts. The total number of managed accounts is the number ofbillable users in the organization, regardless of whether they have verified their email addresses or not. The deactivated accounts are the accounts that have been suspended by the organization admin and do not consume a license. Therefore, you can definitely conclude that you have 8 billable users in your organization12

References = View and manage your bill, Remove or suspend a user