Theres is no direct function to do this in Unleashed as this is more of a finance-related function but below is a process that you can follow if this is something you wish to do.
- Create a Sales Invoice for 100% of the total in Unleashed for a customer (you may want to create a "pro forma" invoice template)
- Receive a 50% deposit from the customer before sending the goods.
- Record the Prepayment in your accounting provider against the customer
- When sending the goods to the customer complete the invoice in Unleashed.
- Match the Prepayment in your accounting provider to the newly created Accounts Receivable Invoice (from Unleashed).
If you are integrated with Xero then you can check the help file here for how this can be done.