Generally speaking, the answer is no; companion tickets or certificates are almost always non-transferable once they have been issued or booked. These perks, often provided by airline-branded credit cards (like the Delta SkyMiles American Express or the Alaska Airlines Visa), are tied strictly to the primary account holder. The standard rule is that the primary cardmember must be one of the travelers on the itinerary. While you can often use the certificate to book a flight for someone else to fly with you, you cannot usually give the certificate to two other people to use without you being present. For example, if you have a Companion Fare from Alaska Airlines, you must be the one purchasing the tickets, and you must be one of the named passengers. Some airlines allow you to cancel a booking and change the companion's name before the flight, but this often involves fees and strict windows of time. If you try to sell or barter a companion ticket, you risk having your loyalty account closed and the ticket voided, as this violates the terms of service of nearly every major carrier. Always check the "Terms and Conditions" section of your specific voucher, as a few rare corporate or promotional versions might have slightly more flexible rules, but these are the exception rather than the rule.