return delivery process for Individual PO

Hi,

what is the process of returning an item to Vendor and what g/l accounts does it hit?

This is concerning Individual PO process (customer -> client -> vendor; vendor delivers to client then client delivers to customer)

I know the process is supposed to reverse g/l postings that were affected during goods receipt, MIRO, outgoing/incoming invoice

but i'm not exactly sure about transaction code involved. Can anyone help?

case 1) goods receipt posted (reverse: CREDIT inventory account, DEBIT GR/IR account)

case 2) goods receipt posted and incoming invoice posted (reverse: CREDIT inventory, DEBIT GR/IR, cancel incoming invoice)

case 3) goods receipt posted, incoming invoice posted, payment to vendor posted

(how do we reverse posting to account payable and cash account here?)

case 4) goods receipt posted, incoming invoice posted, payment to vendor posted, customer invoice posted

case 5) goods receipt posted, incoming invoice posted, payment to vendor posted, customer invoice posted, customer invoice paid.

(how do we reverse posting to account receivable and cash account here?)

I think i have case 1) and case 2) down but i'm not sure what transaction to use for case 3 - 5.

How is account payable and receivable, inventory account, GR/IR, Cost of Goods Sold, and cash accounts going to be reversed?

Thanks.

Quyen