Can Someone Perform Hajj on Your Behalf?
Question

What is the ruling on appointing a deputy to perform Hajj on one’s behalf?
Praise be to Allah.Hajj on your behalf
One of the following two scenarios must apply when a person appoints someone to perform Hajj on his behalf :

That is for an obligatory Hajj
That is for a nafl Hajj. 

Can someone perform obligatory Hajj on your behalf?
If appointing someone to perform Hajj on his behalf is for an obligatory Hajj, it is not permissible for a person to appoint someone else to do Hajj and ‘Umrah on his behalf, except in the case where he is unable to reach the Ka’bah himself because of an ongoing illness for which there is no hope of a cure, or because of old age and the like. If there is the hope of recovery from that sickness, then he should wait until Allah heals him and then perform Hajj himself.  
If there is no impediment to performing Hajj, rather he is able to do Hajj himself, then it is not permissible for him to appoint someone to perform it on his behalf, because he is the one from whom that is required, personally. Allah says (interpretation of the meaning): 
“And Hajj (pilgrimage to Makkah) to the House (Ka‘bah) is a duty that mankind owes to Allah, those who can afford the expenses (for one’s conveyance, provision and residence).” [Al ‘Imran 3:97]
The point of acts of worship is that each person should do them himself, so that he will submit and humble himself before Allah. It is obvious that this purpose, for which acts of worship have been prescribed, is not achieved in the case of one who delegates someone else to do it on his behalf.
Can someone perform voluntary Hajj on your behalf?
But if the person has already performed the obligatory Hajj and he wants to appoint someone else to go and do Hajj and ‘Umrah, then in this case there is a difference of opinion among the scholars. Some of them said that it is permissible, and others disallowed it.
The most correct view in my opinion is that it is not allowed, because it is not permissible for anyone to appoint someone else to perform Hajj or ‘Umrah on his behalf if that is nafl. The basic principle concerning acts of worship is that each person should do them for himself. Just as no one can appoint someone else to fast on his behalf, although if he dies and owes some obligatory fasts, his heirs may fast on his behalf, the same applies to Hajj, which is an act of worship which a person should do himself, physically.
It is not a financial act of worship which is intended to benefit others. Because it is a physical act of worship which a person must do himself, it is not valid if it is done by someone else on his behalf, except in the cases mentioned in the Sunnah, but there is no mention in the Sunnah of anyone doing a nafl Hajj on behalf of someone else. 
This is one of the two views narrated from Imam Ahmad (may Allah have mercy on him), i.e., that it is not valid for a person to appoint someone to perform nafl Hajj or ‘Umrah on his behalf, whether he is able to do it or not. 
Based on the above, the rich who are able to do Hajj themselves should do it themselves, because some people spend many years not going to Makkah and sending someone else to do Hajj on their behalf every year. Thus they miss out on the purpose for which Hajj was prescribed, based on their appointing someone else to perform Hajj on their behalf.” (Fatawa Ibn ‘Uthaymin, 21/136)
The scholars of the Standing Committee favoured the view that it is permissible to do Hajj and ‘Umrah on behalf of a living person who is unable to do that, even if that is nafl.  
It says in Fatawa al-Lajnah al-Daimah (11/81): 
“If you have done ‘Umrah for yourself, it is permissible for you to do ‘Umrah on behalf of your mother and father if they are unable to do it because of old age or sickness for which there is no hope of a cure.”
This view was also favoured by Shaykh Ibn Baz (may Allah have mercy on him). When he was asked: “I want to perform Hajj on behalf of my mother; is it essential to ask her permission, knowing that she has already performed the obligatory Hajj?” 
He replied: 
“If your mother is unable to perform Hajj because she is elderly or is sick and there is no hope of recovery, then there is nothing wrong with performing Hajj on her behalf, even if that is without her permission. 
It is narrated that a man asked the Prophet (peace and blessings of Allah be upon him) for permission, saying, “O Messenger of Allah, my father is an old man who cannot perform Hajj and ‘Umrah.” The Messenger of Allah (peace and blessings of Allah be upon him) said: “Do Hajj and ‘Umrah on behalf of your father.” 
And a woman asked him for permission saying, “O Messenger of Allah, my father is an old man and cannot perform Hajj and ‘Umrah and he cannot travel, can I perform Hajj on his behalf?” He (peace and blessings of Allah be upon him) said: “Do Hajj on behalf of your father.” Similarly many ahadih speak of performing Hajj on behalf of the dead.” (Fatawa Ibn Baz, 16/414)
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And Allah knows best.