you using? I tried ours from Nova Scotia, Canada, and couldn't do it...so I called SW and she gave me the Manchester, NH airport zip code. (That's where we would fly out of if we ever decide to drive/fly)
Apparently, their system isn't set to allow Canadian postal codes.
Ya I tried entering my canadian postal code with no luck so I used one from the Buffalo area as that is where I will be flying out of but I can't figure it out.