The Internet Advertising Bureau (IAB) said a study conducted by PwC showed spending on online advertising reached£5.42bn in 2012.
Overall advertising spending on the internet jumped 12.5% last year, defying a flagging economy as companies battled to reach consumers spending more timeon smartphones andtablet computers.
The study, which used data from companies that had provided information the previous year, said internet advertising spending rose £607m on 2011, with some £323m due to an increase in mobile advertising.
Britain has led the way in moving advertising from traditional areas likenewspapers and radio to the internet.
A high take-up of broadband and the rise of smartphones and tablet computers which allow users to accessthe internet on the go have helped theshift.
"Advertisers are increasingly buying integrated campaigns across online and mobile rather than regarding mobile asan afterthought," director of research and strategy at the IAB Tim Elkington said.
With around two-thirds of adult Britons owning a smartphone as of December 2012, mobile advertising now accounts for almost 10% of all digital ad spending compared with about 1% in 2009.
Video advertising grew 46% to £160m, accounting for 12% of online and mobile display in 2012.
Demand for mobile adverts is likely to increase after auctions for next-generation 4G airwaves earlier this year, which are set to deliver speeds more than five timesfaster than 3G services.
These services will make downloading high-resolution video easier and enable better multi-tasking on the latestsmartphones and tablets.
EE, Britain's biggest mobile operator, said it was now on track to sign up onemillion customers for its 4G service by the end of the year.
The consumer goods sector overtook the financesector as the biggestspender on digital display advertising - accounting for almost 16% of display ad spend in2012.
