atl runner is correct - it is the 9 digit (all numeric) that shows up after you log into your GOES account (it says it's your Trusted Traveler #). We have Nexus & GE and the same 9 digit number is on my Nexus card as "PASS ID". We are DTW based & Mrs. & I flew last week & were invited to the "Special" lane - it was great - shoes on, belt on, coat on, laptop in briefcase, & it took 5 seconds.