An interior designer that provides residential interior design services does NOT need to be registered or licensed with the state. On this point, Florida Statute s. 481.229(6)(a) specifies:
(6) This part shall not apply to:
(a) A person who performs interior design services or interior decorator services for any residential application, provided that such person does not advertise as, or represent himself or herself as, an interior designer. For purposes of this paragraph, “residential applications” includes all types of residences, including, but not limited to, residence buildings, single-family homes, multifamily homes, townhouses, apartments, condominiums, and domestic outbuildings appurtenant to one-family or two-family residences. However, “residential applications” does not include common areas associated with instances of multiple-unit dwelling applications.