When someone tells you to "have a safe flight," the most common and polite response is a simple "Thank you! I'll text you when I land." This acknowledges their well-wishes and provides a point of follow-up. If you want to be slightly more conversational, you could say, "Thanks! I’m looking forward to getting there," or "Thank you, I’ll try to get some sleep on the plane." If the person speaking is also traveling or staying behind to manage things, a reciprocal "Thanks, and I hope you have a great week while I'm gone," is appropriate. In a more formal setting, such as with a colleague or a gate agent, a quick "Thank you, much appreciated," suffices. The phrase "have a safe flight" is a social script designed to show care, so the "reply" is less about the words and more about acknowledging the gesture of empathy. In 2026, with the prevalence of messaging apps, adding "I'll send you a WhatsApp when I'm through customs" has become the modern standard for closing the loop on travel safety anxiety between friends and family.