Originally Posted by
missamo80
I've added my KTN to a reservation after check-in by re-checking in on the mobile app while I'm standing right at the TSA PreCheck line at SeaTac. The boarding card comes back immediately with PreCheck on it.
I do believe that early in the program it was some sort of advance time required, but these days it's instant.
Indeed that usually works too as well as if the reservation is updated by an agent via a phone call. I have done that too when my KTN from my online account didn't populate to the reservation. In my particular instance today it did not update in the app when checking in again and requested I see an agent, most likely because one party in the reservation required wheelchair assistance to the aircraft.
James