A prepayment invoice can be partially paid, but it cannot be applied to a standard invoice or expense report. In order to apply a prepayment to a standard invoice or expense report it must be fully paid. Until it is fully paid, the status of the prepayment remains unpaid.
Why was the prepayment invoice's status displayed as not paid?
Though prepayment is paid partially the status is shown as unpaid on the invoice workbench. This is intended behavior. Though prepayment is paid partially the status is shown as unpaid on the invoice workbench. This is intended behavior. Though prepayment is paid partially the status is shown as unpaid on the invoice workbench. This is intended behavior.