In MoneyWorks a credit note from a supplier is entered as a negative purchase invoice—the window title changes when the Amount field is negative.
It will (when posted) appear in the payables list until either “payment” for it is made, or it is offset against another invoice from the same creditor — see Paying Your Creditors, or Contra Invoices.
For a credit note involving products, you should enter a negative quantity—if these are stocked items, they will be taken out of stock when the credit note is posted. If the credit note is not going to affect your inventory, use a service transaction instead.
