I am frustrated with my inability to receive Pre-check on Southwest. This year I started flying WN, but have never received pre-check. For the record I am Global Entry, always enter my KN number, am DL Plat, UA Gold ( lots of flights!). In the past few years, I have never missed Pre-check on DL and UA. I have tried customer service, and although they were very nice, could not explain why I cannot receive PC. Nothing was ever mentioned about "opt in". Why am I trusted by the other airlines, but not WN? Because of all of the TSA problems this summer, I ended my last call with customer service by saying, reluctantly, that I cannot continue to fly WN .