Credit memo is not getting generated for Billing Frequency Monthly.

Summary:

Hi All,

When I create a Referenced Return Order for a Sales Order with Billing Frequency Monthly then OM is not sending the billing lines to AR for creating the Credit Memo.

But with the same data (everything is same except Biling Frequency) if I create a SO with Billing Frequency One-Time and then a referenced Return Order then system is sending the billing lines to AR for creating the Credit Memo.

Any thoughts on why Credit Memo is not getting generated for the Billing Frequency Monthly ? For our client we need to generate Credit Memo for Billing Type Monthly Return Orders as well, so please suggest.