How do I invoice a blanket purchase order (BPO) for a partial amount?

1. Click Create Invoice > Standard Invoice for the BPO.
2. Enter your invoice number.
   
   You see a quantity of 1 and the BPO amount under the price, and it appears that you cannot edit these fields.
   
   
3. To edit the price or other information in the line item, select the box next to the line item, and click Create.
4. Select Goods or Services, whichever is available and applicable.
5. Edit all line-item information required, and add comments if necessary.
6. Click Create, and the line item appears under the BPO amount as line item 1.1.

Repeat steps 4 through 7 to add another line item to the invoice, if necessary.

1. Enter tax and shipping amounts, if necessary.
2. Click Next.
3. Click Submit.

The Create button is not available on every invoice. If your customer didn't set up the order as a BPO, you won't see this option. For regular purchase orders, you can edit the subtotal within each line item.

SAP Business Network for Procurement & Supply Chain > Transaction Documents > Transaction (Invoicing)
SAP Business Network for Procurement & Supply Chain > Transaction Documents > Transaction (Purchase Orders, Ship Notices & Goods Receipts)