Is it ever possible to find out why I didn’t get TSA Pre-Check?

Yes, if you act quickly. If you print your boarding pass and do not see the TSA Pre-Check indicator, you can call the TSA with the record locator of your reservation and they can usually tell you why you were not selected. The number to call is 1-866-289-9673, and this must be done within the window of 24 hours prior to departure up to 48 hours after the flight. In most cases the reason is one of just a few things so you may want to do a little self-help first and call TSA only if you are unable to find the reason on your own. Check that:

• Your airline and airport participate in the Pre-Check program
• Your Known Traveler Number (KTN) is correctly entered
• Your KTN is in the Travel-On reservation and the airline’s reservation, as very occasionally the airline strips it out
• The name on your ticket, your Pre-Check or Global Entry application, and your frequent flyer profiles all match exactly
• The gender and date of birth on your reservation and your Pre-Check or Global Entry profile are correct and match exactly
• You have not violated any TSA regulations in the past (trying to take a prohibited item through security, even accidentally, can result in exclusion for a period of time)