We had flights on Alaska Airlines booked many weeks in advance for the 30th of July- we received for pre-check on 7.14 and 7/23- put the numbers in our record with Alaska Airlines- and we had pre-check on all our flights no problem. Well worth the time and money.

Also- have scanned the confirmations into my dropbox account on my phone- so if there is any question the official notification is available with me.