While both the wbTimeLog Client Time Tracking and wbTeamPro Project Management Suite can be used for billing clients for time accrued, the methods in which billing is managed is vastly different.
Balance Due Credits (Invoicing AFTER Accrual) Using core wbTeamPro features you can have the system automatically issue invoices after time is recorded. Work is performed and time is recorded before the client has been billed. The settings for scheduling the automatic generation of invoices is robust, allowing you to invoice daily, on a schedule or when actions have been completed.
Pre-Paid Credits (Invoicing PRIOR to Accrual) The wbTimeLog software (which can work in concert with wbTeamPro) allows you to bill clients for "Credits" on a schedule like you would a monthly hosting fee. Credits are then debited by time accrued manually within wbTimeLog, or imported automatically from the wbTeamPro product.