Billing accounts are nothing but user profiles that is created in the tenant portal by the customer. The tenant subscriptions are mapped under each billing account. The service administrator can assign user roles to the billing accounts based on which, when a user logs into the tenant portal, all the subscriptions that are assigned to the billing accounts to which the user has access can be seen under the Usage and Billing tenant extension.
The 'Billing Accounts' menu and the ability to view costs based on the billing accounts in the tenant portal is disabled by default. To use this feature, the 'Show Tenant Usage Costs By Billing Account User Role' settings needs to be turned on from Misc. settings.
Billing Accounts List
Click 'Billing Accounts' menu under 'Manage Subscriptions' section.
Click on the desired billing account.
Available User Roles for Billing Account
Click on 'Add' button to add new user role.
Adding New User Role
Click on 'Save' button.
All Role Assignments for Billing Account
In the 2010 release of Billing solution, only users with role 'Owner' or 'Contributor' can view the usage costs in the tenant portal.