James Timpson is reading an email from one of his shop managers, asking for a second-hand car and a prom dress for their daughter. This might seem unusual for the CEO of a business turning over nearly £300million and employing more than 5,500 staff in 2,100 locations. But neither James nor his firm are exactly run-of-the-mill.

As well as operating Britain’s biggest service retailer, rightly famous for…