A few years ago I signed up for the US Custom and Border Patrol (CBP) Global Entry Program available to Americans and others. Getting approved and acquiring a “Known Traveler Number” (KTN) allows me to skip the lines at passport control in the US, using Global Entry kiosks instead. Adding my KTN number to my airline accounts also results in the “TSA Pre✓” stamp automagically appearing on my boarding passes. This lets me take the faster, shorter lanes at TSA checkpoints, leaving my laptop in its case, shoes on my feet and belt on my jeans.
I arranged an appointment at O’Hare airport for about 6 weeks in the future, the earliest available appointment at the time. I burned frequent flyer miles to fly down from my local airport just for the appointment. Unfortunately, when I got to the CBP office at O’Hare, I realized I had flown down one day too early. The CBP agent at the counter had me stick around and about an hour later they fit me in between appointments. I had a short interview, they took my picture and sent me on my way. My card and KTN arrived a few weeks later in the mail.
I was reminded of this experience today when I ran across a Lifehacker article suggesting that you might try just walking in when you have an extended layover in an airport with a CBP Enrollment Center. You’ll want to make sure you’ve gone through the steps outlined in the “How to Apply” page first. But then try walking in and getting in without an appointment.