Praise be to Allah.
So long as it is demanded of you in the name of zakaah and you pay it with the intention of paying zakaah, then it is zakaah, because the authorities have the right to demand zakaah from the rich and spend it on the causes on which zakaah is to be spent. You do not have to pay any other zakaah from the wealth on which you have paid zakaah to the state. But if you have other wealth or profits on which you have not paid zakaah to the state, then you must give it to the poor who are entitled to it, and others who are entitled to zakaah. And Allaah is the Source of strength. End quote.
Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him)