@mknapp wrote: I just returned from CA and my return flight was not TSA Pre-check even though I booked it including my Know Traveler number. My flight out was TSA Pre-check but not home. How does this happen? I did not have my number with me so I had to go back through regular screening. @mknapp what was your departure airport on the return leg? TSA PreCheck is airport and airline specific. For example Long Beach, CA isn't listed on the Southwest PreCheck page (click here) that includes a list of PreCheck airports. Also on the same Southwest page the following caveat is listed (look under the "Who is eligible?" heading): "...no one is guaranteed expedited screening. Eligibility is determined by the TSA on a per-flight segment basis." So even if you were flying out of an airport with PreCheck there could have been something going on with the TSA system that prevented you from getting the okay for the expedited security.
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