Last Updated on September 17, 2026
In Britain, “interior designer” is not a job title. It is a description, and anyone is allowed to use it. There is no exam you must pass, no register you must join, and no law that stops a person with no training and no insurance from taking a deposit for your home tomorrow.
That is not a scare story. It is the position the profession states itself. The British Institute of Interior Design says plainly that there are “no agreed national standard definitions” of interior designer or interior decorator, and that the field, unlike architecture, has no government regulation. Around 20,000 people were practising as interior designers in the UK on the BIID’s 2021 estimate. Not one of them needed permission to use the name.
The mistake most people make
The mistake is to read the words “interior designer” as a qualification. They are not. The only interior-design words that carry any legal weight in the UK are the three in “BIID Registered Interior Designer”, and they are protected as a registered trademark, not by a law. A trademark stops someone misusing the exact phrase and logo. It does nothing to stop the person down the road calling themselves an interior designer and meaning it.
So the useful question is never “are they an interior designer”. Everyone is, if they say so. The useful question is “what can I actually check”. Here is what you can, and what a blank result really means.
1. The two professional registers
Two bodies assess designers against a published standard. Membership is voluntary, but it is checkable, and it is the closest thing the profession has to a bar.
- BIID Registered Interior Designer. Requires six years of combined education and work experience, current professional indemnity and public liability insurance, and a passed Professional Review against eight core competencies. Members must keep up annual CPD and follow a code of conduct. You can search the BIID directory for the name.
- SBID Accredited. The Society of British and International Interior Design accredits designers who hold a BA (Hons) degree or equivalent plus three and a half years of practice, log 24 CPD points, and carry professional indemnity insurance. An Associate grade exists for those who do not yet meet the full bar.
If a designer claims either title, it takes two minutes to confirm on the body’s own website. If they claim neither, that is not proof of anything. Plenty of good designers never join. It simply means the register is not the place you will confirm them, so you check the next things harder.
2. Companies House, read honestly
If the designer trades as a limited company, they file at Companies House, and you can read when the company was incorporated, whether it is active, and who runs it. That is worth doing, and Whito does it for the firms it names.
But most small design practices are sole traders. A sole trader registers for Self Assessment with HMRC, not with Companies House, so they will not appear there at all. A blank Companies House result for a sole trader is normal. It is not evidence that the business is fake. Treat “not found” as “check them another way”, never as “avoid”.
3. Insurance, because this is the one that pays out
Two cover types matter. Professional indemnity insurance covers you if a design decision goes wrong and costs you money. Public liability insurance covers injury or damage while they work. Both are conditions of the BIID and SBID marks for a reason. Ask to see current certificates before any money moves. A designer who cannot produce them is telling you something.
4. The work, not the words
Ask for the addresses or names behind two recent projects and speak to those clients. Ask what the fee covered and what it did not. A real portfolio survives that call. A borrowed one does not.
The takeaway
The label proves nothing, so stop weighing it. The register, the filing, the insurance certificate and the reference call are the four things that are actually true or false about a designer, and all four are free to check before you pay a penny. The only protected words in British interior design are a trademark, not a law. Everything past that, you verify yourself.
Want to see how you already look to a customer doing this check? The free Whito Visibility Check shows what the record and the search engines say about your business, with no email required. If you are choosing a designer, our study of who the AI engines actually recommend is worth reading first.
Sources
- British Institute of Interior Design, “BIID Registered Interior Designer” and “About Us” (biid.org.uk), read 17 September 2026.
- British Institute of Interior Design, “How many interior designers are there in the UK?” (May 2021 estimate), read 17 September 2026.
- Society of British and International Interior Design, “4 Types of SBID Membership and Their Criteria” (sbid.org), read 17 September 2026.
By Jacob Whitmore, Whito Research. Last checked 17 September 2026. This is general information, not legal advice.
