VietJet Air flight change policy allows passengers to modify their travel dates or routes with applicable fees. Changes must be made at least 3 hours before the original departure time. Fees vary based on the fare type and the time of change. Passengers can make changes through the airline's website, mobile app, or at VietJet Air's ticketing offices. However, changes made through other channels may incur additional charges. It's recommended to review the specific terms and conditions of the ticket purchased for accurate information on change fees and policies.