Research suggests 4G could unlock £5.5 billion of direct private investment into the UK and create or protect 125,000 jobs until 2015.
4G will only be accessible to those with phones like iPhone 5 and Samsung Galaxy SIII LTE.
Until today Britain has used 2G and 3G networks to connect phones and tablets to the internet on the go. 4G allows users to download more quickly with promised speeds 5-7 times faster than today's 3G by 2014.
The long-anticipated 4G network goes live in 11 cities across the country today, including Leeds and Sheffield.
EE (Everything Everywhere) is the first UK provider to give customers access to the network. By Christmas, 16 cities will benefit from the fast connection covering 20 million people.
EE tariff prices will range from £36 for 500mb of download data up to £41 for 8GB of data.
Other cities to benefit from 4G today are:
Cities that will have access to 4G by Christmas are: