Depends on the country/jurisdiction. In some places it is upon issue, in some places it is upon exercise or a mix thereof. Sadly over here in Belgium a non tri

Depends on the country/jurisdiction. In some places it is upon issue, in some places it is upon exercise or a mix thereof. Sadly over here in Belgium a non trivial tax (18%, but it varies according to some parameters such as runlenght) is due upon issue, turning stock options into a potential substantial risk.