When the Princess of Wales wears a designer's clothes, the impact can be immediate. In Jade Holland Cooper's case, it can be initially alarming. The British designer recalled looking at her phone after Kate Middleton first wore her label in 2021 to find around 200 missed calls. Her first thought was that something terrible had happened. Instead, she discovered that the calls were linked to the royal wearing her designs, giving her an unexpected first-hand experience of the so-called 'Kate effect'.
Jade Holland Cooper talking about the Princess of Wales wearing her brand and the “Kate Effect”. pic.twitter.com/hPXB4qgBFg
— Ashhh (@regalmonarchist) October 2, 2026
200 Missed Calls and a 'Supersonic Day'
Holland Cooper, founder of luxury British countryside brand of the same name, recalled the extraordinary episode during an appearance on the Olivia's House podcast. She said she initially had no idea why her phone had suddenly been inundated with calls.
'I had, like, 200 missed calls,' Holland Cooper recalled. She adds, 'Oh my God, someone's died! What's happening?' The reason soon became clear. In May 2021, Kate wore two outfits from Holland Cooper during engagements in Scotland. She wore the brand's double-breasted blazer in the morning before changing into one of its trench coats for an evening appearance.
Holland Cooper described the experience as a 'supersonic day' in which 'the globe goes green' and 'everyone's shopping all over the world'. She also said the brand appeared across press coverage and that royal fashion fan accounts were quick to identify the pieces.
The designer's account illustrates the scale of attention that can follow a royal fashion appearance. She later explained to Forbes that when Kate wears the brand, the customer map on Holland Cooper's website can show activity from around the world, describing it as a 'global blow up'.
Why Kate's Choices Matter
Holland Cooper believes Kate's fashion choices carry particular weight because, in her view, designers cannot simply pay the Princess to wear their clothes. 'She's probably the only person globally you can't pay to wear something,' Holland Cooper said. 'So when she wears something, you know she likes it, [and] she's picked it organically.'
That perception is central to the idea behind the 'Kate effect' — the ability of the Princess's public appearances to generate significant attention for the designers and brands she wears. Holland Cooper's experience was particularly notable because Kate wore two pieces from the label on the same day. Rather than a single high-profile appearance, the blazer and trench coat created two opportunities for the brand to be seen and discussed.
The effect is not limited to Holland Cooper. A recent report also highlighted shoe designer Camilla Elphick, whose shoes Kate wore to a charity polo match in 2022. Elphick said she received a flurry of calls and messages and that the style subsequently sold out.
Why Kate Middleton Once Left This Fashion Designer Panicking and Temporarily Thinking “Someone’s Died” https://t.co/rPexnd4YNa
— InStyle (@InStyle) October 5, 2026
From Panic to Global Attention
For Holland Cooper, the most memorable part of the experience was how quickly an apparent crisis turned into a major moment for her brand. The designer's initial reaction to around 200 missed calls was one of genuine concern. Once she realised why people were contacting her, however, the episode became one of the most significant moments in her career. Holland Cooper has since described seeing Kate wear her designs as 'too good to be true' and said a photograph of the Princess wearing one of her tartan trench coats was something she would 'cherish forever'.
Her story helps explain why the 'Kate effect' remains so closely watched by fashion brands. A royal appearance can introduce a label to audiences far beyond the original engagement, while Kate's choice to wear a particular designer can generate intense interest from royal fans and shoppers.
