The ability to manage credits and debits attached to a Booking is a basic feature of the Channel manager. If you decide to enact a payment gateway, then the deposit and receipts that use electronic payments can be automated and transaction IDs will accompany your Receipts.
Each booking can have receipts of unlimited types credited against a booking(s). In addition, the system will track refunds (debits) and adjustments against any booking. An audit trail of who makes each Receipt assignment or adjustment is saved per booking.