About 27 U.S. states have laws that regulate some aspect of interior design, although the exact count depends on what qualifies as regulation and whether territories and other jurisdictions are included. Most of these laws regulate the use of professional titles, rather than prohibit people from offering interior design services. A smaller number of states give credentialed designers specific authority, such as submitting certain plans for building-permit review. Because state laws change, anyone planning to use a protected title or provide regulated services should check the rules in the state where the work will be done.
How Many States Have Interior Design Laws?
A commonly cited estimate is roughly 27 states with interior design legislation. That figure is best treated as an approximate count, not a single universally agreed total. Sources may count only states with a law specifically addressing interior designers, or they may also count jurisdictions with related certification rules, board oversight, or limited practice rights.
The distinction matters because “regulating interior design” can mean several different things. A state may restrict who can use a title such as “registered interior designer,” while allowing anyone to offer many ordinary design services. Another state may let a qualified designer submit particular documents to a building department. Those laws are not equivalent to a broad requirement that every person working in interior design hold a state license.
For the most current state-by-state details, consult the Council for Interior Design Qualification (CIDQ), state statutes, and the relevant licensing or registration board. The American Society of Interior Designers (ASID) also tracks legislative issues affecting the profession. A national summary is useful for orientation, but the state’s own current law controls.
What “Regulation” Means in Interior Design
State laws generally fall into a few categories. Understanding the category is more useful than relying on a headline count because it shows what a law actually requires—and what it does not.
Title regulation
A title law limits who may use a specific professional designation, such as “registered interior designer” or “certified interior designer.” A person who does not meet the state’s requirements may still be able to provide design services but cannot legally claim the protected title. Requirements can include education, supervised work experience, an examination, and registration with a state agency.
Title protection is often confused with occupational licensing. In many regulated states, an unregistered person may still select finishes, plan furniture layouts, or provide other services, provided the person does not use a restricted title or perform work reserved to another licensed profession.
Practice regulation
A practice act controls who may perform certain services, not just who may use a title. Depending on the statute, it may reserve defined activities to qualified interior designers or require a credential to offer them. Practice regulation is generally more restrictive than title regulation, but its scope is set by the specific law. It does not automatically give interior designers authority over structural engineering, architecture, or other separately regulated work.
Registration, certification, and permitting privileges
Some states use registration or certification systems and give credentialed designers limited privileges. For example, a state may permit an appropriately qualified designer to submit certain interior construction documents for review, subject to statutory limits and building-code requirements. Such permission should not be mistaken for an unrestricted right to design buildings or approve life-safety systems.
Why the State Count Varies
There is no single federal interior design license. Each state sets its own rules, and the rules differ in terminology, scope, and enforcement. A count may vary for several reasons:
- Different legal categories: Some tallies include only practice acts; others count title laws, registration laws, or certification systems.
- Different geographic coverage: Some lists include the District of Columbia, U.S. territories, or other jurisdictions alongside states.
- Changing statutes: Laws can be amended, repealed, or replaced, while online summaries may not be updated at the same time.
- Different definitions of interior design: A law may cover a narrow set of commercial or life-safety-related services rather than all work commonly called interior design.
For that reason, “about 27 states” is a useful high-level answer, while a definitive answer for a particular project requires checking the applicable state statute and board guidance.
What Interior Designers May Need to Qualify
Where a state regulates a title or practice, requirements commonly address education, experience, examination, and renewal. The precise combination varies, so applicants should not assume that requirements in one state apply elsewhere.
| Requirement | What it may involve |
|---|---|
| Education | A degree or other education from a qualifying interior design program, where required by state law. |
| Work experience | Documented professional experience, sometimes completed under supervision. |
| Examination | Passing an accepted examination, often the National Council for Interior Design Qualification (NCIDQ) Examination, if required or recognized by the state. |
| Application and fees | Submitting records to the state board or agency and paying application or registration fees. |
| Renewal | Renewing the credential on schedule and, in some states, completing continuing education. |
The NCIDQ Examination is a professional credentialing exam administered by CIDQ. It assesses knowledge and skills related to interior design practice. Passing the exam does not, by itself, grant a state license or registration; the state’s eligibility and application rules still apply. Details are available from CIDQ and the relevant state regulator.
What State Laws Can Cover
Interior design statutes may address professional titles, eligibility to register, disciplinary authority, and the scope of permitted services. Some also define what documents a qualified designer may prepare or submit. The legal boundary often depends on the project type, occupancy, building size, and whether the work affects structural components or life-safety systems.
Interior designers commonly work on space planning, furniture and finish selection, lighting concepts, and interior construction details. However, a designer’s authority to prepare or submit construction documents varies by state and project. Building departments may require documents to be prepared, signed, or sealed by an architect or engineer when applicable law or code requires it.
Interior design credentials do not replace architectural, engineering, contractor, or building-code requirements. A designer working on a commercial renovation, for example, should determine whether the proposed scope involves a change of occupancy, accessibility obligations, fire protection, egress, structural work, or mechanical and electrical systems. Those matters can trigger separate professional and permitting rules.
Interior Design Regulation and Building Safety
Supporters of regulation often argue that qualified designers working on commercial interiors need to understand building codes, accessibility, fire safety, and occupant health. A project may affect exit routes, interior partitions, finishes, lighting, or other features relevant to public safety. State laws differ in whether and how they connect professional credentials to those responsibilities.
Critics of restrictive laws may argue that broad licensing requirements limit competition or prevent capable practitioners from offering services that do not affect public safety. Many title laws reflect a compromise: they protect a professional designation while leaving substantial room for unregistered practitioners to provide design services. The balance depends on the language of each statute.
Regardless of the policy debate, a credential alone does not ensure that a project complies with every applicable code. Compliance can involve state and local building codes, accessibility standards, fire regulations, zoning rules, and permit procedures. Local building officials determine how adopted codes apply to a specific project.
How to Check the Rules in a Particular State
Before advertising services, signing a contract, or submitting plans, a designer should verify the law for the state where the project is located. These practical steps can help:
- Identify the exact service. Distinguish decorating and finish selection from construction-document preparation, code-related consulting, or permit submission.
- Search the state’s official statute. Look for terms such as interior designer, registered interior designer, certified interior designer, and practice act.
- Contact the responsible agency. A state licensing board or professional regulation department can explain application procedures and point to relevant rules.
- Check local permit requirements. City and county building departments may have forms and document-submission rules that apply to the project.
- Confirm other professional boundaries. Consult the appropriate architect, engineer, contractor, or code official when the scope involves work reserved to another profession.
- Document the verification. Keep copies of official guidance, credential records, contracts, and project decisions.
Search results and professional association summaries can help locate the right agency, but they should not replace the current statute or official board instructions. If the project involves significant construction or uncertainty about protected work, legal advice may be appropriate.
Common Questions About Interior Design Laws
Can someone work as an interior designer without a state license?
In many states, people can provide at least some interior design services without a state credential. Whether they may use a protected title or perform a particular regulated service depends on local law. “No license required” does not mean every service is unrestricted.
Is interior design regulated in every state?
No. State approaches differ, and some states do not have a dedicated interior design credentialing law. Other laws may still apply, including rules for architecture, engineering, construction, business licensing, and building permits.
Does a national credential work in every state?
No national credential automatically overrides state law. The NCIDQ Examination is widely recognized, but each state decides whether it is required or accepted and what additional steps applicants must complete.
Does regulation mean only credentialed designers can decorate homes?
Usually not. Many statutes focus on protected professional titles or defined services rather than ordinary residential decorating. The law’s wording matters, especially when a project involves construction, commercial occupancy, permit documents, or safety-related design.
Key Takeaway
Approximately 27 states regulate some aspect of interior design, but the number depends on how regulation is defined. Most state laws protect a title or establish a credentialing process; fewer give designers specific practice or permitting authority. Since requirements and professional boundaries differ, designers and clients should verify the current rules with the appropriate state board and local building department before work begins.