Choose "Information and Password," then add your PreCheck number in the KTN field in the "Secure Traveler" section. Adding your Known Traveler Number to new AA bookings American Airlines allows travelers to add their TSA PreCheck number at booking. After you've chosen your flight date and ...
If you choose to do so, you'll only be eligible to go through TSA PreCheck when you're flying on that FFP's airline. In order to be eligible for TSA PreCheck for all airlines that allow for the service, you must have a 'known traveller number' (KTN). You must be travelling on ...