Interior design designations vary by state
Indiana is one of 19 states with a law creating a special title for interior designers who have met specified criteria, which vary by state. Such laws, called “title acts,” do not stop anyone from being an interior designer. They simply allow some to add “registered” or “certified” to their title.
Title act — Regulates the use of a title, such as “registered interior designer” or “certified interior designer.” Title acts do not require individuals to become “licensed” to practice interior design.
Practice act — In addition to regulating who may call themselves interior designers, requires individuals practicing interior design to become licensed.
Self-certification — A title act that has no state-run or state-accountable board that oversees the profession.
Permitting statute — The law is an amendment to the architectural statute, adding an exemption for interior designers who have met the education, experience and examination requirements to submit plans for a building permit.
Source: American Society of Interior Designers