After sending the Purchase order to the supplier, the supplier has to send you a Bill created for this PO. The sum of the Bill might be different from the sum of the order. 

You can review the bill, sent by the supplier and see the changes between the order sum and the bill sum. In order to do this, please follow the steps below: 

1. Navigate to the left side menu and choose Bill option. Choose the bill with the status 'Awaiting confirmation' and your PO number. 

2. On the bill page under the information block, there is a list of ordered items. You can see the price of the item that was mentioned in the order in red and a new supplier's price is in blue. 

3. Press Approve button if you accept new price and supplier's bill. 

4. Press Reject button if you do not accept the Bill. You can leave a comment to the supplier by pressing 'Suppliers comment' button to explain the reason for Bill rejection. 

5. After Rejection the bill with your comments will be sent back to the supplier. The supplier can create another bill to the same PO if needed.