Praise be to Allah, The Lord of the Worlds.

Paying Zakah to one`s indebted parent is permissible and avails a person, provided that the debt is due and the mother/father can`t afford to settle it.

An-Nawawi said, "It isn`t permissible to pay Zakah to parent or child on the basis that they belong to the category of the poor and needy-which are amongst the eight categories eligible to receive Zakah-because one is obliged to provide for them. Then, our fellow scholars, Shafie, said, "It is permissible to pay Zakah to parent and child on the grounds that they belong to other categories; namely, the debtors and for the cause of Allah."{Al-Majmou`, 6/229}. And Allah The Almighty knows best.