In 1918 he opened the store which occupied numbers 52-58 on the corner of Parliament Street and King’s Road, opposite the Royal Baths. It traded as a fashion emporium selling haute couture such as boots, fur coats, hats and bags to wealthy tourists and locals. It was famous for having one pane of curved glass wrapped around the main façade. These were good years if you had money and the spa town of Harrogate prospered and with it Copé’s business. Fashion shows became a regular society event at the store with 10 or 12 ‘mannequins’ or models wearing Louis’ designs and around 1,000 distinguished figures attending each show. Shows were also held at the Royal Hall. The clothes were all made at the Parliament Street store, with designers and workrooms upstairs.

Prominent local women would send their maids to have mink repaired or pearl necklaces restored at his shop and ladies’ servants from around the country would contact him asking for fashionable items their employers could wear. By the mid-1920s, Copé had received a request to dress Queen Mary, whose daughter Princess Mary was Countess of Harewood. He was naturalised a British citizen in 1926, married Sarah and they lived on Duchy Road where they raised three children.

As he rose in prominence, Copé came into the possession of a fine gem nicknamed the ‘Tenant diamond’. Valued at £10,000, it was reported in the local newspaper at the time to be ‘bigger and better than any in the British crown’. He became a local philanthropist and great supporter of several charities and good causes and would, for example, organise bazaars to raise funds for the Harrogate Infirmary.

Around the same time business was booming for Louis Copé, Ellis & Goldstein was a renowned fashion house in London, where Sam Goldstein mass-produced fashion for the high street. Goldstein’s business became one of the leading suppliers of womenswear in London's East End and the first to make ready-made dresses (rather than bespoke tailored clothing) for the average height lady, which at the time was 5ft 2". The family had links to Leeds and Louis Copé’s daughter Freda was introduced to Sam Goldstein’s son William. When they married, they joined the two families and fashion powerhouses together.

The shop was sold in the late 1970s but some of the clothes can still be viewed in the Harrogate Museums collections. A plaque was recently added to the former premises and unveiled by Copé’s great-grandson, Alex Goldstein. Copé is also remembered by a window in the Harrogate synagogue.