Lea Verou Oh wow, I hadn't looked at the rules in a while and was actually considering "switching" to passes for our family, including our 2yo! I don't think that there's going to be any such enforcement at the airport, since you'd just show up there with a valid ticket or better yet a valid boarding pass which would get you directly through security, so it would have to be done when purchasing the pass (doing it when trying to buy tickets with it would cause more problems), where you are probably required to enter your birthday (can't remember now from 1 year ago when I purchased it for my mother).

It's actually a very good question and I can't understand why they would include such a rule (I mean 12yo obviously also won't be buying their own passes, so it can't be because of legalities regarding the young age of the customers).
Anyway, we're still quite a long way (about 1 year) before the next flights I'd need to book for us, so if I do choose the passes it won't be something I'd be buying any time soon.