Answered by Shaykh Yūsuf Badāt
Can I do nafl (optional) ṭawāf and or ‘Umrah on behalf of others, and if allowed, can it be for only one person or can I do it on behalf of multiple people?
Umrah and ṭawāf as nafl (optional) acts of worship can be rendered on behalf of one person or many people. The rewards of the deed will be blessed to the doer and all those that were intended, whether they are alive or deceased. (See Rad al Muḥtār)
Majority scholars regard this as permissible and valid. There are numerous prophetic reports and actions of the noble Companions to substantiate the validity of this practice.
“Perform Ḥajj and ‘Umrah on behalf of your father!” (Tirmidhī)
“It is permissible for the one who fasts, performs prayers and gives charity, to gift its rewards to someone who is either dead or alive. The reward reaches them, according to the Ahl al Sunnah wal Jama’ah (Sunnis)” (Badāi’ al Sanāi’)
Hamash (may Allāh be pleased with him) says, “I saw Alī (may Allāh be pleased with him) slaughtering two sheep, so I asked him why he is slaughtering two sheep.” He said, “The Prophet (peace and blessings upon him) made a bequest that I should render Udhīyyah for him.” (Tirmidhī).
Abbās (may Allāh be pleased with him) says that Sā’d ibn Ubādah (may Allāh be pleased with him) was away when his mother passed away. When he returned he asked the Messenger of Allāh (peace and blessings upon him), “Will it be of any benefit if I give charity on her behalf? The Prophet (peace and blessings upon him) replied in the affirmative”. (Bukhāri)
The Messenger of Allāh (peace and blessings upon him) laid down a ram [to sacrifice], and slaughtered it saying, “In the name of Allāh! O Allāh, accept from Muḥammad, the family of Muḥammad and the ummah (community) of Muḥammad.” (Saḥīḥ Muslim)
And Allāh Knows Best