Ad description

A website for the British Institute of Interior Design,, seen on 11 June 2019. Text at the top of the home page stated, “THE UK’S LEADING PROFESSIONAL ORGANISATION FOR INTERIOR DESIGNERS".


The Society of British and International Interior Design challenged whether the claim “THE UK’S LEADING PROFESSIONAL ORGANISATION FOR INTERIOR DESIGNERS” was misleading and could be substantiated.


The British Institute of Interior Design t/a BIID, stated that there were only two professional organisations in the UK that represented interior designers: BIID and the Chartered Society of Designers (CSD). BIID used membership numbers as a measure of substantiation for the claim. They showed that the number of their members was significantly higher than those for the CSD. BIID stated that these figures clearly showed that they were the UK’s leading professional organisation for interior designers. They further stated that they did not believe the complainant would meet the commonly accepted understanding of the term ‘professional organisation’ because they did not publish their member list on their website. Also the complainant did not specify the length of term of office for its directors or that the directors must be elected by the membership.



The ASA considered that, in the absence of any qualification, consumers were likely to understand the claim “THE UK'S LEADING PROFESSIONAL ORGANISATION FOR INTERIOR DESIGNERS” to mean that, relative to other organisations in the field of interior design, they had the highest total number of members.

We noted that BIID only provided evidence that compared their size with one other organisation. They had excluded other interior design organisations, such as the complainant, on the basis that the complainant had not listed their members or specified a length of term of directors. However, we considered that consumers would not interpret the claim so rigidly and would instead understand the claim to be referring to all organisations for interior design professionals, including the complainant. We therefore did not consider that a comparison with only one competitor was adequate to demonstrate that BIID had the highest number of members relative to other interior design organisations/member bodies in the UK. For those reasons, we considered that BIID had not provided adequate evidence to substantiate the claim and concluded that it was misleading.

The ad breached CAP Code (Edition 12) rules 3.1, 3.3 (Misleading advertising) 3.7 (Substantiation) 3.33 and 3.35 (Comparisons with identifiable competitors).


The ad must not appear again in its current form. We told the British Institute of Interior Design not to claim that they were the “leading professional organisation” without holding comparative evidence that showed they had more members than any other professional interior design organisation, or to make clear which types of interior design organisations they were comparing themselves with.

CAP Code (Edition 12)

3.1     3.3     3.7     3.33     3.35    

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