Goods Return 
The goods return document is used to return delivered goods to vendors or to reverse a purchasing transaction for an item completely or partially, for example, a goods receipt PO in SAP Business One. Due to legal stipulations, you cannot delete or make any accounting-relevant changes to these documents. However, to return unwanted or faulty goods, or to correct errors made when entering the above-mentioned documents, you can create a goods return.
When you create a goods return, the goods are issued from the warehouse and the quantities are reduced. If your company uses perpetual inventory, SAP Business One automatically creates the relevant posting to update the inventory values as well.
You can create a goods return either based on a goods receipt PO or not. If you choose to do the latter, and run the perpetual inventory by moving average, make sure that the prices of the items in the independent goods return are identical to the prices posted in the respective original purchase transaction.
When you create a goods return document based on a purchase order, you can choose to reopen the item quantity of the order. To be able to do so, the checkbox Enable Reopening of Orders When Creating Returns Based on Orders must be selected in the document settings. For more information, see Document Settings: Per Document Tab.
Reopening the item quantity has the following consequences:
The status of the purchase order changes to Open.
The open quantity is increased by the item quantity in the goods return document. If the sum of the remaining open quantity plus the returned quantity is higher than the quantity in the original order, the open quantity is increased up to the quantity in the original order.
The delivered quantity is decreased by the quantity in the goods return.
For service type transactions, the open amount is increased accordingly by a value equal to the value from a goods return line. If the sum of the remaining open amount plus the returned amount is greater than the total amount for the original order line, the total amount is used as the open amount.
If there are any freight charges related to the returned item, these charges are reopened in the same way as the item quantities.
If the item is managed by batches, the returned batch-allocated quantity is increased by the quantity from the return line.
To access the window, choose 
Purchasing – A/P 
Goods Return 
.
Prerequisites
No A/P invoice has been created for the goods being returned. If an invoice has been created, you must create an A/P credit memo. For more information, see A/P Credit Memo.