How do I add my TSA PreCheck to Delta? To add your TSA PreCheck to your Delta reservations, begin by logging into your Delta Air Lines account. Once logged in, access your profile or account settings to proceed. Look for the option to input your TSA PreCheck Known Traveler Number (KTN), which is a 9-digit code you received when approved for TSA PreCheck. After entering your KTN, be sure to save the changes you've made. As a final step, when you check in for your flights with Delta, verify that your boarding passes display the TSA PreCheck indicator.