With your agency account, you can easily manage customer packages, adjust credits, downgrade, or apply for an upgrade.
If you use this function to order and set up a non-costfree package for a customer account, billing will be done using the payment data of the agency account. The performance (credits & package) will still be activated for your customers account. The prerequisite for this is that you have deposited payment data in your account (which also acts as an agency account at the same time).
The invoice will be issued to you, the agency, but the service will be paid by your customer. You can see the invoice in your account. The packages are automatically renewed.
If the customer changes the package himself via his own account, the order will also be debited from his account. It will then be charged for the payment data of the account and not the agency account.