Answer
Wa `alaykum As-Salamu waRahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
If Hajj was due on a Muslim, but he died before performing it, his heirs should authorize someone to perform Hajj on his behalf.
Answering your question, the General Iftaa’ Department in Jordan, states the following:
There are two situations in which it is permissible to authorize someone to perform Hajj (Major pilgrimage ) on behalf of another:
First: If Hajj was due on a Muslim, but he died before performing it, his heirs should authorize someone to perform Hajj on his behalf and cover all the Hajj expenses from the deceased’s estate.
It is also permissible for a Muslim, an heir of the deceased or not, to perform Hajj on his behalf voluntarily .
Second: If a Muslim was inflicted with an incurable disease, or was too old to travel, and was financially capable to cover the expenses of Hajj, then he should authorize someone to perform it on his behalf, even with paying him a wage.
Read also:
Is It Permissible for Someone Else to Make Hajj on My Behalf?
Can You Make Hajj on Behalf of Dead Brother?
Can You Perform Hajj or `Umrah on behalf of a Sick Person?
Is Obligatory Hajj Required Before Performing It on Behalf of Another?
Almighty Allah knows best.