As an additional data point: provincial income taxes in Canada are collected along with federal income taxes by Revenue Canada and then remitted down to the pro

As an additional data point: provincial income taxes in Canada are collected along with federal income taxes by Revenue Canada and then remitted down to the provinces. The sole exception to this being Quebec. Definitely a peculiarity of the US system being less cohesive than some other countries - and also dealing with far more people and jurisdictions.