Birmingham-born Caudwell, 64, is backing Unshackled.com, a website allowing customers to convert phones on payment plans to Sim-only contracts. He netted £1.24bn when he sold Staffordshire-based Phones4U in 2006 and another £100m after it was sold again in 2011. He had earlier sold his Singlepoint billing operation to Vodafone for £405m. Property development is now his main business interest. He owns a 16th-century manor in Staffordshire and has planning permission to transform a Mayfair car park into flats that could be worth £2bn.
Despite hefty charitable giving, Birmingham-born Caudwell is valued at £1.514bn. His Caudwell Children charity spent £5m on good causes last year. Its star-studded annual Butterfly Ball at London's Grosvenor Hotel raised £1.7m.
Relative values: John Caudwell, the founder of Phones 4u, and his daughter, Libby