25. Mike Lynch — Net worth: £470 million ($718 million)
Where the money came from: Lynch founded the software company Autonomy, which then sold to HP for £6.5 billion ($9.94 billion).
Age: 45
Overall rank on the Sunday Times Rich List: 235
22. Sir Peter Rigby — Net worth: £550 million ($841 million)
Where the money came from: Rigby is behind Specialist Computers, one of the country's largest independent IT suppliers.
Age: 71
Overall rank on the Sunday Times Rich List: 199
23. Kevin Cash — Net worth: £500 million ($764 million)
Where the money came from: Cash has invested in a number of internet firms, as well as London real estate. An "elusive" figure, there are few photos of him out there.
Age: 51
Overall rank on the Sunday Times Rich List: 217
24. Peter Jones — Net worth: £475 million ($726 million)
Where the money comes from: The entrepreneur seen on "Dragon's Den" recently launched Brandpath, a merger of his previous telecoms investments.
Age: 49
Overall rank on the Sunday Times Rich List: 232
21. Scott Farquhar — Net worth: £586 million ($896 million)
Where the money came from: Farquhar is one of the two co-founders of software company Atlassian.
Age: 35
Overall rank on the Sunday Times Rich List: 192
20. Mike Cannon-Brookes — Net worth: £591 million ($904 million)
Where the money came from: Cannon-Brookes co-founded software company Atlassian.
Age: 35
Overall rank on the Sunday Times Rich List: 189
19. Andrey Andreev — Net Worth: £700 million ($1.07 billion)
Where the money came from: Andreev created Badoo in 2006, a London-based social network popular in Latin American.
Age: 35
Overall rank on the Sunday Times Rich List: 160
18. Mo Ibrahim — Net worth: £710 million ($1.08 billion)
Where the money came from: Sudanese-born, Ibrahim's fortune comes from telecoms, and he founded African telecommunications company Celtel.
Age: 68
Overall rank on the Sunday Times Rich List: 159
17. Ruth Parasol and family — Net worth: £715 million ($1.09 billion)
Where the money came from: Parsol made her first fortune in online porn before switching gears and founding online gambling company PartyGaming, which is responsible for PartyPoker.
Age: 48
Overall rank on the Sunday Times Rich List: 158
16. Niklas Zennström — Net worth: £780 million ($1.19 billion)
Where the money came from: Zennström is one of the co-founders of internet communications platform Skype.
Age: 49
Overall rank on the Sunday Times Rich List: 140
15. Simon Nixon — Net worth: £945 million ($1.44 billion)
Where the money came from: In 1993, Nixon created Moneysupermarket.com, a price comparison site. It had 2014 revenues of £248 million ($380 million).
Age: 47
Overall rank on the Sunday Times Rich List: 120
14. David Ross — Net worth: £1 billion ($1.53 billion)
Where the money came from: Ross' billion-dollar fortune comes from co-founding mobile phone retailer Carphone Warehouse.
Age: 49
Overall rank on the Sunday Times Rich List: 108
13. Lord Sugar — Net worth: £1.04 billion ($1.59 billion)
Where the money came from: One of Britain's best-known businessmen, Lord Sugar founded consumer electronics company Amstrad in 1968.
Age: 68
Overall rank on the Sunday Times Rich List: 101
12. Sir Terry Matthews — Net worth: £1.04 billion ($1.59 billion)
Where the money came from: Matthews is a telecoms entrepreneur, starting out working at British Telecom and going on to found Mitel and Newbridge Networks.
Age: 71
Overall rank on the Sunday Times Rich List: 101
11. Alki David and the Leventis Family — Net worth: £1.25 billon ($1.91 billion)
Where the money came from: The Greek entrepreneur runs TV channel streaming site FilmOn amongst other Internet ventures, and his family is also invested in Coca-Cola Hellenic.
Age: 46
Overall rank on the Sunday Times Rich List: 80
10. John Caudwell — Net worth: £1.45 billion ($2.22 billion)
Where the money came from: The Caudwell Group, launched in 1986, sold mobile phones while they were still in their infancy — making Caudwell rich. Its retail arm was Phones 4u. Caudwell ultimately sold on the business in 2006.
Age: 62
Overall rank on the Sunday Times Rich List: 65
9. Sir Michael Moritz and Harriet Heyman — Net worth: £1.75 billion ($2.68 billion)
Where the money comes from: Moritz is chairman of Silicon Valley venture capital firm Michael Moritz. He has invested in PayPal, Google, Yahoo!, Zappos, YouTube, and numerous other tech companies. He has also written a book on Apple.
Age: 60
Overall rank on the Sunday Times Rich List: 52
8. Sir Charles Dunstone — Net worth: £1.9 billion ($2.91 billion)
Where the money came from: Dunstone co-founded mobile phone retail chain The Carphone Warehouse, and also chairs the TalkTalk group.
Age: 50
Overall rank on the Sunday Times Rich List: 51
7. Denise, John and Peter Coates — Net worth: £2.35 billion ($3.6 billion)
Where the money came from: Peter's daughter Denise founded Bet365 in 2000, which has since grown to become one of the biggest online gambling companies in the world. Brother John also helps run the company.
Age: 47
Overall rank on the Sunday Times Rich List: 44
6. Teddy Sagi — Net worth: £2.53 billion ($3.87 billion)
Where the money came from: Sagi founded Playtech in 1999, a software company that helps power online gaming and gambling. It had 2014 revenues of €457 billion.
Age: 43
Overall rank on the Sunday Times Rich List: 39
5. Mark Scheinberg — Net worth: £2.76 billion ($4.22 billion)
Where the money came from: Scheinberg co-founded the wildly successful online gambling platform PokerStars along with his father.
Age: 41
Overall rank on the Sunday Times Rich List: 36
4. James Dyson — Net worth: £3.5 billion ($5.36 billion)
Where the money came from: Dyson is a prolific British inventor, and famous for his high-tech hoovers.
Age: 68
Overall rank on the Sunday Times Rich List: 22
3. Sir Richard Branson — Net worth: £4.1 billion ($6.28 billion)
Where the money came from: The rockstar entrepreneur began by launching his Virgin Records music stores, which have eventually morphed into the more than 400 companies under the umbrella of the Virgin Group. One notable tech venture is Virgin Galactic, Branson's space exploration company.
Age: 64
Overall rank on the Sunday Times Rich List: 20
2. Sir David and Sir Frederick Barclay — Net worth: £6.5 billion ($9.96 billion)
Where the money came from: The Barclay brothers have a broad portfolio, including the Telegraph newspaper. Under their ownership it has rapidly modernised for the digital age — but has seen a fair amount of controversy in the process.
Age: 80
Overall rank on the Sunday Times Rich List: 13
1. David and Simon Reuben — Net worth: £9.7 billion ($14.8 billion)
Where the money came from: The two brothers' family moved to the UK from India in the fifties. They invested heavily in the metals market, but have since turned their gaze to property and internet investments. They own Global Switch, one of the largest data centre providers in Europe and Asia.
Age: 73
Overall rank on the Sunday Times Rich List: 5