It is very important to note that a Muslim husband does not need to pay Zakat Al-Fitr on behalf of his non-Muslim wife, according to the majority of Muslim scholars, whereas on the other hand, Abu Hanifah and his followers see that a man in this case is obliged to pay Zakat Al-Fitr on behalf on his non-Muslim wife.
Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, states the following: Zakat Al-Fitr is to be paid by the head of the household for himself and for those he is obliged to maintain, i.e. his family members including his wife. Although all Muslim scholars agree that a man is obliged to sustain his non-Muslim wife, they differ concerning paying Zakat Al-Fitr for her.
The majority of scholars including Malik, Ash-Shafi`e and Ahmad maintain that a man is not obliged to pay Zakat Al-Fitr for his non-Muslim wife, because she is not herself required to pay it because she is outside the boundaries of Islam. They base their opinion on the view suggesting that a non-Muslim is not charged for the branches of Shari`ah. It is, moreover, reported that the Prophet (peace and blessings be upon him) prescribed Zakat Al-Fitr on all Muslims, free and enslaved; male and female; young and old. Also, Zakat Al-Fitr is considered a way to purify the fasting person from lewdness and abuse, as reported by Abu Dawud with a sound chain of transmitters, on the authority of Ibn `Abbas (may Allah be pleased with them both). Hence, it is meaningless to demand non-Muslims to pay Zakat Al-Fitr, as they are not required to observe fasting like Muslims.
The fore-mentioned hadith restricts prescribing Zakat Al-Fitr to Muslims. In the hadith, the word ‘Muslims’ refers to the persons on whose behalf Zakah is paid, not the person who pays it. Therefore, it is not necessary for a man to pay Zakat Al-Fitr on behalf of his non-Muslim slave even though he is obliged to maintain him. The same ruling applies to a non-Muslim wife. (Ibn Qudamah;Al-Mughni; vol. 2, pp. 646-647)
Abu Hanifah and other scholars of Ashab Ar-Ra’i maintain that a Muslim has to pay Zakat Al-Fitr on behalf of his young son who apostatizes from Islam, because one is not accounted for apostasy unless he fulfills the conditions of legal accountability including adulthood. They also opine that a man should pay Zakat Al-Fitr on behalf of his Christian or Jewish slave. They base their view on the fact that a father is obliged to maintain his young son and a master his slave. They cite a hadith from the Prophet (peace and blessings be upon him) in which he says: “Pay half a Sa` of barley (one Sa`= 2.176 kilograms) on behalf of everyone, free or slave; young or old; Jew, Christian or pagan.” However, the majority of scholars have refuted this hadith saying that it is not reported in the well-known books of tradition.
Some argue that Zakat Al-Fitr purifies the fasting person from committing any lewdness or abuse, and is, thus, not paid on behalf of non-Muslim family members due to the fact that they do not fast. However, it is paid in favor of the needy on behalf of those who are excused from fasting. Hence, a non-Muslim wife or slave is in the same position as the excused.
This claim is also refuted by the fact that if a Muslim does not observe fasting in Ramadan without a valid excuse, he will be charged with two things; to make up fasting and to pay Zakah. Neither of the two replaces the other.