Both travelers must be booked at the same time and on the same reservation, and travel must be reserved and completed by the expiration date on the certificate. If either ticket is canceled, the other will be as well. Finally, the Companion Certificate is only valid on round-trip tickets.

When you cancel a flight booked with a companion ticket (such as an Amex Companion Certificate or a Southwest Companion Pass), the outcome depends on the specific airline's 2026 policy, but generally, the companion's reservation is automatically voided once the primary traveler's ticket is cancelled. For certificate-based travel (like Delta or Alaska), if you cancel a "wholly unused" itinerary, the certificate is usually re-deposited into your account, provided it hasn't passed its original expiration date. However, if the certificate has already expired, you will likely lose it entirely. For the Southwest Companion Pass, the companion's flight is simply cancelled, and any taxes paid are refunded. It is crucial to note that you cannot "swap" the primary traveler while keeping the companion on the same booking; the entire record must be re-evaluated. Always check if a cancellation fee applies to the primary ticket, as the companion usually only pays government taxes which are fully refundable.