You can Add Payments to any transaction in OPEN status. The payments made are reflected on the receipt print-out and added to the Till on the day of the payment.
Find the transaction to which you want to add payment from the Sales Ledger, then click the Add Payment button.
This will open the transaction details window, and display previous payments made and current Balance Due
Click the green Add Payments button enter additional payment
The transaction will get updated, and the print/email option will show the payment data.
If the payment is received in full, the transaction status will change from OPEN to PAID.