Q: Is Zakat obligatory on someone who lacks mental capacity?
A: According to all jurists, a sane person qualifies to pay Zakat if other conditions are found. A sane person is one who has mental capacity. According to the Hanafi school, Zakat is not obligatory on an individual who lacks mental capacity. According to the majority of scholars, Zakat is obligatory on the wealth of those who lack mental capacity.
The Hanafi school are of the view that a person with continuous insanity and mental incapacity is exempt from Zakat. Such as, someone who lost their memory from Amnesia, or is medically diagnosed as “insane” were they are unaware (and is therefore not entirely responsible) of what they are saying or doing.
However, a person with intermittent sanity is still required to pay Zakat.