Hi,

Here are some suggestions from Sage Knowledgebase Article #79576"

• Doubtful receipt entry under A/P-A/R, Payments, Doubtful receipt entry can be used.
  • Review online Function help.
• Use a journal entry to show the return.
  • Unmatch the invoice from payment so that invoice is open.
  • Create journal entry to write-off the payment.
  • Match the payment in Manual Matching to the journal.

If you use the journal entry, you might want to set up its own document type so it stands out.

Thank you!