You must enable the Consume Wallet During Invoicing? field setting as follows:
Go to Setup>Custom Settings>Billing System Properties.
Click Manage.
The Custom Settings Billing System Properties page
displays.
Click System Properties.
The Billing System Properties details page displays.
Click Edit.
The Billing System Properties Edit page displays.
Select the Consume Wallet During Invoicing?
checkbox.
Click Save.
The field setting is
enabled. Now if you associate the wallet with an asset then the wallet balance updates only
after the billing schedules are invoiced. For more details on wallet drawdown, see Wallet Manager
and Real-Time Wallet Updates.