Originally Posted by
canadiancow
If you need a passport to travel, you need a DOB. Domestic Canadian flights do not require a DOB.
Noted. WestJet isn't clear on it not being mandatory on a quick glance.
That being said, the issue does sort-of remain that the airlines really
should be loading some sort of checkbox there regarding age (and then bouncing back hard if the booking agent(s) aren't checking the right boxes).
Edit: And of course, with airlines generally seeming to require it, I think the term "negligence" comes to mind here: They require the DOB and technically allow the booking of a UM (often a UM
well below the age threshold) on a stand-alone PNR.