Research conducted by Ofcom has revealed that almost three-quarters of UK premises can receive a signal outdoors from all five main 3G networks.
The media regulator's new coverage map reveals that 73 per cent of homes and businesses can use mobile broadband services delivered by Vodafone, Orange, T-Mobile, O2 and Three.
In terms of landmass, a signal from all five major 3G networks is available in 13 per cent of the UK – with the majority of rural and remote areas lacking full coverage.
Ofcom's data indicated that household mobile broadband coverage is significantly better than geographic coverage at present, emphasising the fact that broadband providers are focusing their energies on urban centres.
With 27 per cent of UK premises lacking a full range of 3G options, around 7.7 million homes and businesses still have limited mobile broadband choice, Ofcom estimated.
The areas of lowest 3G geographic coverage were found to be in the highlands of Scotland and mid-Wales, regions which are hilly and sparsely populated.
Ofcom said it is currently working closely with the government to consider how the £150 million allocated to help address mobile not-spots can be best-invested, helping to improve coverage for dongle users.
"Working to address mobile not-spots is one of Ofcom's priorities as set out in its 2011-12 annual plan," the regulator stated.
Ernest Doku, technology expert at uSwitch.com, said the coverage maps – the first of their kind – had offered "an extraordinary insight" into Britain's voracious appetite for online services.
He suggested that as the adoption of mobile technology continues to rise across Britain, the importance of 3G broadband will steadily increase.
"There were 76.4 million active mobile connections in March 2011 - dwarfing the number of people who live here, which last year was a mere 62.3 million," Mr Doku added.
"If ever proof were needed of the triumph of the mobile, this is it."