What is the ruling on using the family name "Ahmadi" instead of "Ahmad" or "Muhammad," and is this considered imitation of Qadiyanism?

It is permissible for the family name to be "Ahmadi" instead of "Ahmad" in two cases: The first is if the original name is "Ahmad" and the nisbah (relative adjective) "ya" is added for the family. This is permissible as long as it does not lead to confusion with the deviant sect "Ahmadiyya." In this case, it is legislated to clarify the lineage. The second is if the original family name is "Ahmadi." This is also permissible as long as it does not lead to confusion. If that occurs, it is legislated to clarify that it is a family lineage and not related to the deviant sect.