I set the price for inventory and non inventory items then I set user restriction for my sales only to view and create sales order and sales invoice. But when my sales input the sales invoice they can change/edit the price so they can set over/under the price that I set before, why? Can I lock the price in order to they can’t to change/edit the price?
No, you cannot. Prices set for items are really only shortcuts, allowing the form to be automatically filled when an item is selected. Everything on the transaction form can be edited: price, description, default tax code, etc.
It potetially to fraud, doesn’t it?
Fraud prevention must be addressed by management oversight, not by restrictions in the program.