I'm in BC, Canada, and I think it's all pay-first here. On the other hand, some places will accept debit cards at the pump, and it just pre-authorizes some set

I'm in BC, Canada, and I think it's all pay-first here. On the other hand, some places will accept debit cards at the pump, and it just pre-authorizes some set amount before permitting me to fill the tank. Of course, I'm only charged for the amount dispensed. This strikes me as a reasonable solution, in that it removes the need to guess how much I need beforehand.