Hi Rafael: One option would be to add a product for Shipping Cost and add it in the PO. 

Hi, well it's not the same, since the delivery method has some important functions such as having delivery charges based on rules or checking the delivery quota box for having free charges about a specific amount.. as offered by the delivery methods in the sales module. but it's of the same importance to the purchasing module, since you have to manage your suppliers... @odoo is there a way of activating the delivery methods in the purchase module?