How to: Undo Quantity Posting on Posted Receipts
If you have made an incorrect quantity posting, that is, if you have made a purchase order with, for example, the wrong number of items and posted it as received but not invoiced, you can undo the posting.
To undo a quantity posting on a posted receipt
In the Search box, enter Posted Purchase Receipts, and then choose the related link.
Open the posted receipt that you want to undo.
Select the posted receipt line that you want to undo.
On the Lines FastTab, choose Functions, and then choose Undo Receipt.
A corrective line is inserted under the selected receipt line.
If the quantity was received in a warehouse receipt, then a corrective line is inserted in the posted warehouse receipt.
The Quantity Received and Qty. Rcd. Not Invoiced fields on the related purchase order are set to zero.