Locking prices on a Purchase Order means that once the Purchase Order has been saved, then neither the user or the system can change the prices. This is useful when you have negotiated special prices with your supplier. A step by step guide can be found below the video.
Steps
Ensure the Purchase Order is in Editmode.
Turn on the Lock Price toggle.
Save the Purchase Order.
Notes/Caveats
Note: Prices can be locked by default in the Purchasing section in System Values.