Hey everyone! I’m Diana Barnes and I love to travel. Today, I want to talk about my experience that Many people are unsure How Do You Add TSA PreCheck® to United Airlines? To do this, simply log into your MileagePlus account, navigate to Profile & Preferences, and input your Known Traveler Number (KTN) under Personal Information. For flights already booked, head to My Trips, choose your flight, and update your traveler details with your KTN. You can also add it during the booking process for faster security screening.