While LLCs and S Corporations share some characteristics, they also have several specific differences: LLCs can have an unlimited number of members, while S Corps can have no more than 100 shareholders or owners. Additionally, non-U.S. citizens/residents can be members of LLCs, while S Corps may not have shareholders who are non-U.S. citizens/residents. And corporations, LLCs, partnerships, or trusts can’t own S Corps.