Postings at Goods Receipt and Invoice Receipt 
Postings at Goods Receipt and Invoice Receipt
In the SAP System, goods receipts and invoice receipts are offset to a clearing account (the GR/IR clearing account).
A Simple Example of a Goods Receipt Posting and an Invoice Receipt Posting
When you receive goods, the system credits the value of the goods (goods receipt quantity x net order price) to the stock account and posts the offsetting entry to the GR/IR clearing account. The GR/IR clearing account is cleared when the invoice is posted to the vendor account.