You can match a Credit Memo to an invoice even if it is paid and posted

Dear Colleagues,

Release 12.0.6

Matching Credit/Debit Memos to Purchase Orders and Invoices

You can match to an invoice even if it is paid and posted (according to the page 3-88 in the Oracle Payables User's Guide).

Use a price correction when a supplier sends an invoice for a change in unit price for an invoice you have matched to a purchase order or receipt (according to the page 3-65 in the Oracle Payables User's Guide).

Record a Price Correction...You must specify the number of the original invoice in the Find window (according to the page 3-90 in the Oracle Payables User's Guide).