We have enabled incoming payment for the salesman at the counter. Normally they only enter sales orders or sales invoices. In some cases however they receive some payments from customers. So what we instructed them is to goto incoming payments, select the customer and select the invoice. Then press CTRL-Y to select the payment means. They select cash or cheque if applicable and then they type the amount or use CTRL-B to take the amount from the invoice. So far so good.
However when the invoice e.g. is $87 and the payment is $50 the difference of $37 is automatically set to bank charge(!)
Is there a way to block the use of this difference by the salesman? They should not be able to post amounts as bankcharge or otherwise any difference account.