When an existing LLC or s-corp wants to do business under another name, they add a DBA, also called an Assumed Business Name, to their LLC or s-corp registration with the Idaho Secretary of State. Begin by going to the Secretary of State’s website and completing an Assumed Business Name form. List the LLC/s-corp as the owner of the DBA, not a person, then submit. It’s that easy. It then becomes ABC LLC doing business as XYZ.