What Suffices for Hajjata al-Islam and What Does Not Suffice? (The following Chapter is best explained by fatwa).

16. A number of our people have narrated from Ahmad ibn Muhammad from al-Hassan ibn Ali from Rifa’ah who has said the following: “I once asked abu ‘Abd Allah عليه السلام, about the case of a man and a woman who die without performing al-Hajj; if Hajjahta al-Islam can be performed on their behalf. He (the Imam) said, ‘Yes, it is permissible.’”