His father forgets whether he paid Zakah, should his son pay it on his behalf?

Q: I present to Your Eminence the fact that my father got old and is retired and hence stayed at home. He possesses money in the bank but he is often forgetful. Zakah (obligatory charity) is due on his money deposited with the bank. When he is asked about its Zakah, he says he paid its Zakah. However, owing to my acquaintance with his accounts, I know that he has not paid the obligatory Zakah. I am in charge of many of his works and I can pay his Zakah. Is it permissible for me to do so without his knowledge and approval? Give us a Fatwa. May Allah reward you with the best!

A: If you have a legal Wakalah (appointment of a legally accountable person to act on behalf of another for a specific permissible matter) to be in charge of the money of your father, it is obligatory for you to pay Zakah on his behalf. If you do not have such a Wakalah, you have to come to the Mahkamah Shar`iyah (a court dealing with family affairs of Muslims) to take a legal Wakalah to be in charge of your father's money in a way that develops and preserves his money and pay Zakah out of it. May Allah help all to succeed in all goodness and righteousness!May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.