The easiest way to check a Coach serial number is to call Coach directly. Coach customer service representatives can verify the serial number on the phone so that the owner of the item knows immediately whether or not it is authentic.
Check the logo tag in the bag and make sure that the word "COACH" is not imprinted, but raised. The trim on the bag should match the logo tag. For example, if the bag has a green trim, the logo tag should be green. There are only a few places that Coach authorizes to sell their items, including Coach stores, authorized department stores and Coach factory stores.