Trying to decypher the TSA bar code for PreCheck

[chrisinhouston]

My wife and I are Global Entry qualified with US Customs and also registered for the TSA PreCheck program and get the fast lane through security most times but not always as it is supposed to be a random thing.

Normally you have no idea if you will get the 3 beeps at the TSA check point. They read the bar code on their little scanner and if you get 3 beeps you get the fast lane and one beep and you get the cancer machine or the full body grope. Recently we noticed that sometime our United boarding passes have a PreCheck symbol and we have always gotten the fast lane after reading the bar code.

Today my wife got an upgrade to B/F for her flight home tomorrow and when she printed the boarding pass it did not have the PreCheck symbol so she went back to the United site and moved to another seat in that cabin and printed the BP and it did have the PreCheck symbol.

She sent me a pdf of each BP and I pulled them into Photoshop and cranked up the resolution and cropped just the bar code and made it bigger so it would be easier to read. Printed each one and then used the bar code reader on my phone.

Interestingly they are slightly different, the first part is all the same on each as it has her name, flight info and UA flier info. The second part is has a different set of alphanumeric stuff. It would be interesting to try both boarding passes and see what they do but I don't think the TSA would like that.