Whether your brother can use your flight credit depends entirely on the type of credit and the airline's specific 2026 policy. Standard "travel credits" or "vouchers" issued for a cancelled flight are usually non-transferable, meaning they are tied to the name of the original passenger. However, some airlines, most notably Southwest Airlines, offer "Transferable Flight Credits" on certain fare classes (like Wanna Get Away Plus) that can be easily moved to another person’s Rapid Rewards account. On legacy carriers like Delta or United, credits are strictly for the named individual unless they were issued as a "transferable voucher" due to a major service failure or bumping. If your credit is non-transferable, the only way for your brother to use it would be if you are also on the itinerary. Always check the "Terms and Conditions" in your airline's mobile app or wallet to confirm if the "Transfer" button is active for your specific credit.