Once you create a sales order you can accept deposit from your customer. You can accept multiple advance payments on that sales order even before fulfilling or delivering any items to the customers. “Order Advance Payment” creates a advance invoice for the sales order. You can simply add payments on this invoice and email or print the invoice to the customer. This invoice will show how much money the customer has so far deposited.

At the time of actual fulfillment a new invoice is generated. You can simply adjust the payment in the new invoice to show payment due.