Who are the UK’s fastest-growing tech firms in 2012?This year’s Hiscox Tech Track 100, published in yesterday’s Sunday Times, offers a fascinating snapshot into entrepreneurial Britain. Listing some of the UK’s fastest-growing firms, it highlights the hottest sectors in the tech economy right now, and also provides ample proof that if you have a good business idea you can succeed, regardless of the general business climate.

The firms featured in the ranking have shrugged off the economic gloom to grow in leaps and bounds in the past year. The average sales growth for the top 100 firms was 81% and their revenue totalled £2.7 billion.

Essence topped this year’s ranking, a digital marketing firm whose clients include Google, eBay, Betfair, Expedia and YouTube. Its sales have jumped 284% a year, to £170m in 2012 from £3m in 2009.This is the 12th edition of the list, which ranks private technology, telecoms and digital media companies according to their sales growth over the past three years.

The firms that appear in the ranking tend to be young and energetic. Over half of the 100 companies have not appeared before; 14 of the top 20 didn’t even feature in last year’s list. Two thirds of them burst into life within the past decade. For example, MadBid.com was created in 2008 and already turns over £7.5 million, while musicMagpie.co.uk, an online entertainment trader, has sales of over £63 million despite only being set up in 2007.

The digital media and entertainment sector dominates this year’s ranking, with 18 firms, ranging from computer games developers like Supermassive Games to online marketing consultancies such as MobileWebAdz. They generated overall sales of £637 million. Online consumer services, including Madbid.com and Just-Eat, is the second-largest sector with 14 companies, followed closely by telecommunications with 13 companies, such as Lycamobile and Orca Digital.

Several of the firms have ridden the smartphone tidal wave. A fifth of the companies either develop smartphone apps, use apps to boost their sales or help telecoms networks cater for people’s insatiable appetite for data.

Green technology is another of the fastest-growing sectors, with nine companies on this year’s ranking, ranging from turbo-generator producer Bowman Power to energy-efficient chipmaker CamSemi.

These business success stories exhibit a few common themes. Many of them have international ambitions: two-thirds of the companies on the list have international operations or plan to expand overseas in the near future. A number have already hit the M&A trail to accelerate their growth, reach new markets, expand their product range and exploit economies of scale; 20 firms have made 35 acquisitions. Several have seized on the importance of developing strong brands to drive growth and have ploughed money into marketing themselves, such as music recognition app maker Shazam.

Their rapid growth has not come at the expense of earnings for most of the top 100 firms. Nearly three quarters of them made an operating profit in 2011/2012, with the average profit margin being 11%. Several are spectacularly profitable: 12 have an operating profit margin of over 20%, while nearly a third make a profit of more than £1 million.

Online moneylenders Wonga.com and WageDayAdvance are the two most profitable firms on the table. Wonga made an operating profit of £63 million, while WageDayAdvance has an operating profit margin of 48%.

Over half of the companies remain in the hands of their founders or of entrepreneurs, while private equity or venture capital firms control a further 39 of the companies on the list. Only 10 of the top 100 have raised money from PE or VC firms in the past year, fewer than half the number that got financing deals the year before.

To read the full report click here .