Q: Can a person perform ‘umrah on behalf of many people (say 100)?
A: There is no harm in that.
Q: If a group of people agree to appoint a person (not necessarily being one of them) for performing ‘umrah mufradah on behalf of all the group members by distributing ‘umrah expenses equally among them, is this procedure accepted by Islamic law?
A: The thing significant is that all group members completely accept to help the chosen person, i.e. all agree to hire him as their na’ib.