How do I add TSA after booking Delta? If the passenger has already made the booking with Delta Airlines and would like to add TSA, it can very easily be done through the steps that have been described here as follows: Visit the official website of Delta Airlines. Scan over the page to find the Login icon. Login with the credentials asked to retrieve details of My Profile. Scroll to find the Personal details tab and then add the TSA Precheck number that was assigned.  Make the final submission so that the boarding pass has TSA PreCheck.  Can I add my TSA PreCheck number to the Delta app? It is not possible for the passenger to add their TSA precheck number through the Delta Mobile app. But it is possible to add KTN to Delta reservation in the profile section. This will enable the passenger to get their PreCheck details on their mobile app as per their requirement. The KTN needs to be added to the profile through the web browser. Is a Known Traveler Number the same as a TSA PreCheck? The Known Traveler Number and TSA PreCheck are not the same. Known Traveler Number is usually assigned to all the passengers who have received approval in their TSA PreCheck. Once received, the passenger needs to add it so that the TSA PreCheck indicator appears on the boarding pass. TSA precheck is a security initiative that has been formulated by the airline so that passengers get to have a good travel expedition.  Can you add TSA PreCheck after checking in? Yes, it is indeed possible to add TSA PreCheck after checking in. If the passenger would like to know; how to add TSA precheck to an existing Delta flight, they can do so by going over the official website of the airline. Once there, the passenger can find their reservation through My Trips and then make all the necessary additions to update the details of their PreCheck.  Click here for more details: https://www.sohafares.com/blog/how-to-add-tsa-precheck-to-your-delta-reservation