Rank Company Location Year end Annual sales rise over 3 years Latest sales £000s Staff Comment
1 EssenceDigital marketing agency Central London Mar 12 283.94% *170,014 157 Helped grow market share for Google web browser Chrome from 3% to 31% in EMEA
2 LycamobileInternational telecoms operator Central London Feb 11 247.25% 116,829 17 Lycamobile operates in 14 countries across Europe and Australia
3 Wonga.comOnline money lender Central London Dec 11 244.57% *184,674 131 Has loaned over £1bn since 2008 and processes 6bn pieces of data each month
4 MobileWebAdzMobile advertising provider Central London Mar 12 217.72% *8,494 24 Operates in 50 countries and plans to open an office in Brazil, its seventh worldwide
5 DisplaydataElectronic shelf-labelling provider Berkshire Mar 12 212.80% *12,114 61 Spun out of Qinetiq in 2000 and spent eight years developing its 'e-paper' technology
6 musicMagpie.co.ukOnline entertainment trader Cheshire May 12 191.31% *63,238 850 Started out as a website for trading in used CDs, DVDs and games
7 Nomad DigitalTransport communications provider Newcastle Jun 11 185.69% 18,981 71 Hopes to expand market share abroad with recent acquisitions in Germany and Australia
8 WageDayAdvanceOnline money lender Yorkshire Dec 11 171.85% 34,186 105 Founded by Dale Chapman, who once claimed to be the UK's youngest pawnbroker
9 AlertMeSmart home monitoring provider Central London Dec 11 168.99% *7,583 83 Recently announced deal with American home improvement retailer Lowe's
10 UnrulyVideo advertising platform Central London Mar 12 157.61% *17,574 73 Has run campaigns for adidas, Evian and Xbox
11 Equal ExpertsSoftware developer Central London Mar 12 154.90% *10,470 100 Delivers bespoke software solutions to blue-chip clients, including O2, Fidelity and UBS
12 UbiquisysTelecoms services provider Swindon Dec 11 151.82% 14,066 87 Has sold nearly 1m of its mobile phone network boosters
13 Reward GatewayEmployee engagement technology provider Central London Jun 12 145.13% *118,731 123 Opened a New York office in March 2012
14 Evance Wind TurbinesWind turbine developer Loughborough Mar 12 144.28% *7,252 35 Potential growth in Japan as the country moves away from nuclear following 2011 tsunami
15 BCS GlobalVideo-conferencing services provider Slough Dec 11 138.49% 5,941 20 The NHS uses its videoconferencing services to support smokers who want to quit
16 MedicAnimalOnline pet products retailer Northwest London Dec 11 118.42% *†14,860 150 Its websites offer live chat facilities with vets in five languages
17 SkyscannerTravel search engine Edinburgh Dec 11 118.20% *†21,701 127 Its mobile apps have been downloaded 9m times since launching in 2011
18 Bowman PowerElectrical turbogenerator developer Southampton Dec 11 116.99% 8,439 70 Its generators capture lost heat energy from engine exhaust flow
19 RarewavesEntertainment retailer Central London Aug 11 113.40% 6,424 34 Founder also launched retail start-ups in the 1980s and 1990s
20 OmnifoneDigital music provider Central London Apr 12 106.28% *29,341 160 Entering Japan with Sony this year, and targeting growth in India and China
21 Zamir TelecomInternet telecoms provider Central London Nov 11 101.00% *23,085 50 Diversifying into green energy infrastructure projects in Africa and Asia
22 Click TravelTravel management system developer Birmingham Mar 12 98.91% *30,007 57 Began as a bedroom project whilst the managing director was a university student
23 Forward Internet GroupMedia developer and investor Central London Dec 11 96.71% *139,293 218 Recently acquired one of Europe's largest publishers for biking enthusiasts
24 BarrachdSoftware developer Edinburgh Jan 12 93.35% 6,222 30 Sells software that can monitor staff absenteeism and sentiments in social media
25 AyimaSearch optimisation consultancy Central London Dec 11 93.12% *5,308 25 Its proprietary tools can emulate Google's algorithms to assess search results
26 MediafedDigital advertising provider Central London Mar 12 93.08% *5,023 38 Plans to open its first overseas office in Beijing by the end of the year
27 P2iLiquid repellent nano-coater Oxfordshire Jul 11 91.15% 6,021 90 Its technology can protect up to 100,000 mobile phones per day from water damage
28 MaxymiserOnline customer experience optimisation Central London Dec 11 86.41% 6,016 114 Raised £7.5m in January from backers including Investor Growth Capital
29 CamSemiEnergy-saving chip developer Cambridge Dec 11 85.43% *6,527 56 Founded by Cambridge professors as a spin-out of research into energy efficiency
30 Peach TelecomTelecoms services provider Hampshire Aug 11 85.42% 7,711 54 Has acquired three competitors since inception and plans for more
31 JUST EATTakeaway website Central London Dec 11 84.84% *35,092 443 Says it has recently become the UK's most popular food website
32 KeytreeDigital IT services Central London Aug 11 84.56% 5,843 60 Won SAP's Innovation Partner of the Year award in 2011 and 2012
33 Fonix MobileMobile software developer Central London Dec 11 83.58% *5,021 15 Has done interactive shows for Channel 4 and Sky
34 XConnectTelecoms services provider North London Dec 11 82.17% *9,331 55 Signed a four-year deal with DE-CIX, the world's biggest internet exchange
35 AcademiaEducational IT consultancy North London Jun 11 81.40% 22,900 48 Has sold more than 10,000 iPads in the past six months alone
36 The Hut GroupOnline retailer Northwich Dec 11 80.84% *142,000 542 Investors include former chief executives of Marks & Spencer and Tesco
37 New Earth SolutionsWaste treatment technologies developer Dorset Jan 12 77.79% 24,687 120 Planning to grow from waste management into energy recovery by January
38 Supermassive GamesComputer games developer Guildford Dec 11 75.94% 5,677 90 Nominated in 2011 for a Develop Excellence award as best new European studio
39 OpenCloudNetwork platform provider Cambridge Jun 11 72.20% 6,695 78 Produces the software to manage the switch-over to 4G broadband
40 FixnetixFinancial trading services provider Central London Mar 12 72.08% 28,134 75 Its technology can execute a trade in less than a millionth of a second
41 MadBid.comAuction website operator Central London Jun 12 70.32% *7,509 40 Launched a sister website, Let's Haggle, in early 2012
42 Smart TrafficDigital marketing agency Bristol Mar 12 67.72% *6,196 167 Plans to open an Australian office and increase market share overseas
43 MooOnline stationer Central London Dec 11 67.50% 12,779 92 Integrated with Facebook Timeline this year so users can make cards using their Facebook details
44 EviivoHospitality software developer Central London Mar 11 66.49% 7,689 84 Recently opened offices in France and Tunisia
45 MimecastEmail management services provider Central London Mar 12 65.76% *31,070 260 Won Microsoft Innovative Customer Advocacy Partner of the Year award in June
46 WorldStoresOnline retailer West London Jan 12 65.34% *34,991 130 Sells more products online than Tesco direct, B&Q and Homebase combined
47 UkashOnline payment provider Central London May 12 64.78% *19,805 59 Ukash vouchers are available at over 445,000 outlets worldwide
48 BlueGnomeGenetic diagnostics developer Cambridge Dec 11 64.55% *11,825 34 Has recently opened an office in Singapore and a US office is planned for this autumn
49 Updata InfrastructureNetwork services provider Reigate Jun 11 62.98% 22,218 62 Provides bespoke telecoms solutions for businesses, schools, and GP surgeries
50 Solar CommunicationsCommunication systems provider Wiltshire Dec 11 62.51% 8,590 50 Has attracted five of its largest 20 customers within the last year
51 Invenio Business SolutionsIT consultancy Reading Mar 12 60.39% *5,513 51 Implemented the tax management software for the Republic of Maldives
52 Oxford ImmunotecMedical diagnostics provider Abingdon Dec 11 58.52% 7,970 97 Sells its tuberculosis diagnosis product to hospitals in over 40 countries
53 UK2.netInternet services provider Central London Dec 11 58.22% *28,639 193 Sponsors the Marussia F1 Team
54 Ovation IncentivesReward programme software developer Central London May 12 58.14% *7,662 23 Says it was the first UK company to launch Amazon.co.uk’s "Gift Codes On Demand" service
55 Intelligent EnergyPower systems developer Loughborough Sep 11 57.13% 11,869 166 Developing clean energy engines for use in two and four-wheeled vehicles
56 agenda21Digital media agency Central London Dec 11 57.04% *12,572 48 Has won work from major customers Bacardi and Elemis
57 ANS GroupHosting services provider Manchester Mar 12 56.99% *46,789 130 Says it is the first Cisco partner in EMEA to achieve cloud builder status
58 Consumerchoices.co.ukPrice comparison website Central London Mar 12 55.71% *10,835 48 Says it saves consumers who switch services via their websites an average of £363
59 Excelerate TechnologyCommunication technology developer Cardiff Oct 11 55.04% 6,228 35 Plans to open first office abroad in Australia in 2013
60 LivebookingsRestaurant reservation service Central London Dec 11 54.94% *7,774 160 Says that mobile devices now account for 20% of its bookings
61 WEMS InternationalEnergy management services Stockport Jul 11 53.75% 11,862 63 Its systems can help businesses reduce energy costs by 30%
62 Intelligent EnvironmentsTechnology and outsourcing provider Central London Dec 11 53.31% 23,081 600 Delivers digital banking solutions to more than 50 clients including Barclaycard
63 BlockIT consultancy Central London Mar 12 52.51% 15,176 44 Secured work with big NHS trusts in Nottingham, Sheffield, Leeds and York in the last year
64 OneComTelecoms services provider Hampshire Dec 11 52.11% 17,387 98 Won Vodafone's Partner of the Year award in 2011 and 2012
65 KeycomTelecoms services provider Stafford Sep 11 51.98% 6,729 69 Provides broadband connections to residence halls and military barracks
66 ECO PlasticsPlastic bottle recycler Lincolnshire Dec 11 50.28% *34,600 157 Its sorting facility is dubbed one of Europe's largest and most technically advanced
67 ShazamContent recognition services Central London Jun 11 50.27% 15,600 92 One million people in the US used its TV app to access more Super Bowl footage
68 TH_NKDigital marketing agency Central London Oct 11 50.13% 12,675 120 Its founders started the company while students at Newcastle University
69 SiracomWireless systems consultancy Basingstoke Dec 11 49.63% *7,828 16 Provides wireless IT services for primary and secondary schools
70 The FoundrySoftware developer Central London Dec 11 49.09% *15,358 91 Licenses its products to film-production studios in Hollywood and Bollywood
71 StaffcarePensions software developer Surrey Jun 12 48.65% *5,663 63 Launching products to help companies cope with changing pensions regulations
72 CSA WaverleyIT services provider Buckinghamshire Jul 11 48.41% †24,515 22 Won the 2011 award for HP Technology Services Partner of the Year
73 FluidataInternet services provider Central London Mar 12 48.29% 7,197 40 Plans to invest £2.5m upgrading its network following the London Olympics
74 Adconion Media GroupDigital advertising distributor Central London Dec 11 47.96% *176,154 574 Says it serves more than 100 billion advert impressions on the internet each year
75 I am ITIT infrastructure consultancy Central London Jun 11 46.84% 11,017 17
76 KelwayIT services provider Central London Mar 12 46.83% 350,710 742 Says its customers include more than one-third of FTSE 100 companies
77 Lab21Clinical diagnostics Cambridge Dec 11 46.83% *11,410 125 Sells its diagnostic products to over 100 countries worldwide
78 fuse8Digital marketing agency Leeds Mar 11 46.40% 5,058 37 Carries out its development work at its operation in Chelyabinsk, Russia
79 Belcom247Telecoms infrastructure management East London Dec 11 45.52% 5,205 50 Customers include US telecommunications provider CenturyLink
80 m-hanceSoftware provider Stockport Dec 11 45.24% *†9,617 126 Made four acquisitions in 2011, including Calyx Software and Gyrosoft
81 CentekOilfield equipment manufacturer Devon Oct 11 45.05% 12,598 81 Is poised to open a manufacturing plant in Oklahoma in the US
82 PMGC Technology GroupIT and telecoms services provider Central London Apr 12 44.65% *12,385 61 Managing director used to drive racing cars professionally
83 InnoviseSoftware developer Slough Sep 11 43.86% 19,018 160 Has bought 13 companies in eight years and now has more than 700 customers
84 Mosaic IslandIT development consultancy Bristol Jul 12 43.40% *7,952 10 Customers include Which?, Sky, AOL and Everything Everywhere
85 Markco MediaDigital media agency Central London Jul 11 42.94% 10,513 69 The founder has appeared on the C4 programme 'The Secret Millionaire'
86 CitihubIT consultancy Central London Dec 11 42.89% *13,793 95 Benefiting as banks step up investment in trading technology after the global crash
87 Metronet (UK)Internet service provider Manchester Mar 12 42.79% *5,869 37 Has built a hybrid fibre optic and wireless network for UK businesses
88 Audio NetworkOnline music publisher Central London Jun 12 42.61% *9,275 54 Has an online library of 50,000 music tracks used by customers including the BBC
89 Focus GroupTelecoms services provider East Sussex Nov 11 42.56% *12,460 68 The Labour Party and London Broncos are among its customers
90 FarncombeDigital television consultancy Basingstoke Dec 11 41.17% *6,954 35 Built the platform that underpins Freeview's digital terrestrial TV service
91 eCommeraeCommerce services provider Central London Mar 12 40.69% *17,846 176 Enjoys share of House of Fraser's online sales after relaunch of retailer's website
92 Cambridge CognitionMedical software developer Cambridge Dec 11 39.89% *5,867 49 Helps GPs screen patients for early signs of neurological disorders
93 Autologic DiagnosticsCar maintenance software developer Oxford Dec 11 39.46% *†15,008 93 Sells its software to 5,500 independent car workshops, most of which are in the US
94 Cascade TechnologiesIndustrial instruments manufacturer Stirling Mar 12 39.45% 6,061 49 Spun out of the University of Strathclyde's physics department
95 Bell MicrosystemsIT services provider Portsmouth Sep 11 39.24% 51,291 82 Opening offices in Melbourne and Hong Kong this year
96 PortalIT consultancy Bracknell Mar 12 39.07% *21,107 58 Has been named IBM's business software partner of the year
97 Zinc AheadCompliance software developer Oxford Mar 12 38.86% *7,217 62 Opened an office in Sydney in June to support customers in the Asia Pacific region
98 ASLHMachine-to-machine communications provider Northampton Dec 11 38.27% *6,392 16 Plans to expand to continental Europe, North America, and Australia
99 TIM GroupFinancial software developer Central London Dec 11 38.26% 9,065 102 Says its products are used by top 10 brokers globally
100 XexecReward programmes administrator Northwest London Nov 11 38.21% *13,666 35 Provides bespoke rewards programmes for corporate employees

* supplied by company  † annualised figure