Hi,
No need MR11 transactions!
In your case as no issue with quantity and have isuue with value, then go for Subsequent credit /subsequent debit in t.code:MIRO.
Your situation rarely happned to business where your vendor send invoices or credit memos that refer to transactions that have already been invoiced.To map,you can go for subsequent debit/credit process for total invoice value of a purchase order item but the total invoice quantity remains unchanged. The processes are:
1) Subsequent credit or even subsequent debit is done when total “VALUE" of invoice is changed.
2) Total invoice Quantity is remained same. Only value based transaction takes place & not quantity base.
3) If credit memo is received from memo then subsequent credit is done in MIRO.
4) This is done for purchase order items if an invoice is already posted and cannot refer to particular invoice
5) Listed separately in PO history and purchase order total values is updated but not Quantity
Regards,
Biju K