Customer projects support two types of prepayments; Payment on account and Down payment.
Prepayments are specified from the project stage "Contract Preparation" when billing due dates are being specified for the billing items. Due dates for prepayments need to be assigned the corresponding prepayment type in the field "Item Usage", as well as the amount of the prepayment.

- Time and Expenses billing items support both prepayment types; Payment On Account and Down payments.
- Fixed Fee billing items only support Down payments.
- Other billing item types (usage based and periodic service) do not admit prepayments.