Does he have to pay zakaat al-fitr on behalf of the orphan whom he is sponsoring?
Question

                Many people sponsor orphans; do they have to pay zakaat al-fitr on their behalf?
Praise be to Allah.
      Zakaat al-fitr is obligatory upon every Muslim, whether 
      male or female, young or old, because of the hadeeth of Ibn ‘Umar (may 
      Allah be pleased with him) who said: The Messenger of Allah (blessings and 
      peace of Allah be upon him) enjoined zakaat al-fitr upon the people at the 
      end of Ramadan, a saa‘ of dates or a saa‘ of barley, upon everyone, free 
      or slave, male or female, among the Muslims. Narrated by al-Bukhaari 
      (1504) and Muslim (984). The orphan is included in the general meaning of 
      the word people. 

    Based on that, if the orphan has any wealth, zakaat al-fitr 
    must be paid from it; it is an obligation upon him that he must pay from his 
    own wealth, and the one who is sponsoring him does not have to give zakaat 
    al-fitr on his behalf, because he is able to afford it. But if his sponsor 
    gives it on his behalf voluntarily, that is acceptable. 

    An-Nawawi (may Allah have mercy on him) said: The orphan who 
    has wealth is obliged to pay his zakaat al-fitr from his wealth, in our 
    opinion. That was also the view of the majority of scholars, including 
    Maalik, Abu Haneefah and Ibn al-Mundhir. End quote from al-Majmoo‘, 
    6/109 

    Al-Bahooti said in Kashshaaf al-Qinaa‘ (2/247): It is 
    obligatory upon every Muslim… male or female, old or young, because of the 
    report quoted above, even if he is an orphan. It must be paid from the 
    individual’s wealth. That was stated [by Imam Ahmad]. End quote. 

    But if the orphan does not have any wealth, then his zakaat 
    al-fitr must be paid by the one who is Islamically obliged to spend on this 
    orphan among his relatives. As for the one who is sponsoring him: he is not 
    obliged to pay zakaat al-fitr on his behalf, because he is spending on him 
    voluntarily. 

    This is the view of the majority of scholars (including the 
    three imams, Abu Haneefah, Maalik and ash-Shaafa‘i), because they say that 
    zakaat al-fitr is obligatory upon every Muslim and those whom he is obliged 
    to support. The one who sponsors an orphan is voluntarily sponsoring him, so 
    he is not obliged to give zakaat al-fitr on behalf of the orphan. 

    The view of Imam Ahmad is that whoever is spending on a 
    person during the month of Ramadan, even if he does so voluntarily, is 
    obliged to give zakaat al-fitr on that person’s behalf. Imam Ahmad stated 
    that whoever takes in an orphan girl must give zakaat al-fitr on her 
    behalf. 

    Some of the Hanbalis, such as Ibn Qudaamah, favoured the view 
    that this is not obligatory, and they interpreted the words of Imam Ahmad 
    mentioned above as meaning that it is mustahabb (recommended). 

    See: al-Mughni (4/306); ash-Sharh al-Kabeer, 
    (7/97) 

    To sum up: the one who voluntarily sponsors an orphan is not 
    obliged to pay zakaat al-fitr on behalf of the orphan. Rather zakaat al-fitr 
    must be paid from the orphan’s wealth if he has any wealth; if he does not 
    have any wealth then zakaat al-fitr must be paid by his relative who is 
    Islamically obliged to spend on him.

    And Allah knows best.