For United you can have your parents and children use your unlimited flight benefits. Also your spouse or "domestic partner," all of which you need proof to establish the relationship. Then you get 24 "buddy" aka companion passes a year, which are per person, per SEGMENT. The "buddy" doesn't have to travel with you so long as it is not First on an international three-cabin aircraft. They do have a lower boarding priority than if they were traveling with you. As an employee your boarding priority drops if there is more than one "buddy" traveling with you. Service charges for the buddy passes are the same as an ID90. For employees/spouses/dp's/children/parents the flight is free if you get on in economy. First or Business is a percentage off of established ZED fares.