But, to be honest, that's really not that much different than in the US. While you hear a lot about incentive stock options (ISOs) in the US not being taxed until you sell them, in reality most people who exercise ISOs will have to pay alternative minimum tax (AMT, a kind of parallel tax scheme to 'normal' taxes) when they exercise. When I exercised my options I had to pay more in tax than I did for the exercise price of the options themselves.