Follow these steps to process a return of goods entry in the Purchase Order (PO) module:

1. Open Purchase Order, Mat Req/Return, then Return of Goods Entry.
2. Click the # button for the Next Return NO.
3. You can leave the PO number blank. Enter the original PO number to reduce its quantity and allow re-receiving. This will also provide an audit trail in Receipt History for that PO. 
4. You can leave the invoice number blank if you don't need a credit on the vendor account. To create a credit on the vendor's account, enter an invoice number. You can't reuse the original invoice number. To reference it, use the original invoice number with an "A" or "C" suffix.
5. If the PO number is blank, select the Vendor No.
6. On the Lines tab, select the Item number, enter the Ordered, Received, and Returned quantity, then click OK.
   •  NOTE: The system relieves inventory based on the inventory costing method. If using Average cost, the system will use the current average cost. FIFO method relieves the first cost tier, not the received cost tier. Sometimes, it's different than the receipt cost.   
   •  NOTE: You can correct the quantity and cost if the FIFO tier is incorrect.  
7. On the Totals tab, click Accept.
8. Print and post the Return Order Register and the Daily Transaction Register. The system uses the register's print date for transactions in Inventory Management and General Ledger.
9. Apply the credit invoice to the original invoice in Accounts Payable, Main, and Manual Check Entry.

 CAUTION: If both PO number and Invoice number are blank, the transaction will only impact Inventory Management. 

What is the Item Cost Hierarchy? Where does the Unit Cost on a Purchase Order in Sage 100 come from?