Hello @norman2 ,
Yes, you can do this.
When you Receive Payment and enter the amount of the payment, any amount exceeds the outstanding invoices will be put to Amount to Credit. This remains on the customer's account until such time as you have more invoices for that customer. At that time, you can apply the outstanding credit to invoices until available credit amounts are used up.
You do that by going back to Receive Payment and entering in the customer name. Any available credits for that customer will show up in the Credits section of the Receive Payment window, and will be automatically applied (unless you have that option turned off, in which case you would manually apply them) to outstanding invoices.
Good luck!
