A friend of mine divorced his wife. His wife has the custody of the children. Should he pay zakah on behalf of the children or is this the duty of their mother, given the fact that he pays them monthly alimony?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

Zakah Al-Fitr of the aforementioned children is obligatory on their father if the children are under the age of puberty and if he is able to do so. That he divorced the mother of the children does not exempt him from the obligation of paying zakah Al-Fitr on their behalf. 

As for his wife, the person in hand is not required to pay zakah on her behalf if he has divorced her irrevocably or that her waiting period will expire before the eve or dawn of Eed al-Fitr.

Allaah Knows best.