Hello Richard,
Payment terms only apply to 'Invoice' type documents that need to be paid, and so the 'payment term' field is available for the document types of invoices, debit memo's, finance charges and service/repair. The amount is due and if they pay early then a discount is taken at the time of payment. The payment term follows the invoice, not the payment document. That is why if you select any 'payment' types such as credit memo's, returns, warranties, or cash receipts, the payment term field then becomes unavailable. You do not put a 'payment term' on a 'payment type' because it already is a payment.
The discount is driven by the 'payment term' on the invoice that you are applying the credit memo to, and the 'Apply date' that is used. (You can see in the RM20101 that invoice type documents carry the payment term in the PYMTRMID column, and this is blank for any cash receipts or credit memo's or payment type records.)
The documents are already keyed, so changing it at the customer card level really wouldn't have any impact on posted documents.
Under Transactions | Sales | Edit transaction Information, you can change the 'discount date' for the invoice that you are applying the credit memo to. If the customer has a 2%/net 10' payment term, and that is carried on the invoice (inv date of Feb 1 for example), then 2% will be taken if you apply a cash receipt or credit memo prior to Feb 10, and will not be taken if you apply it 10 days after. So you really can drive whether the discount is taken or not, by adjusting the 'discount date' on the invoice itself to be before or after the apply date you are using.
Hope that helps. Do some testing and review the window above to see for yourself.
Thanks
Cheryl Waswick
Microsoft Dynamics GP
