Three has announced a December launch for its 4G network with existing 3G customers being the first to benefit.
The service is switched on in London, Birmingham and Manchester at the end of the year, when every Three customer who has a 4G enabled device will be upgraded to the superfast network for free.
Further cities will be then switched on in January with the hope that 1.5 million customers will benefit from 4G services by early next year.
All Three subscribers will have to do is install a simple software update with no need to go in store. There will be no new contracts to sign and no need to change tariffs or swap SIMs.
Three will also be the only 4G network to offer all you can eat data. O2, Vodafone and EE all offer capped data plans only.
Three's announcement comes as O2 and Vodafone switch on their 4G network for the first time today. Both plan to cover around 10 cities by the end of the year.
This week, EE announced that its 4G network, first launched 10 months ago, is now available in over 100 towns and cities in the UK, covering 60 per cent of the population.
Three has said its 4G population coverage will reach 98 per cent by the end of 2015 and be available in 50 towns and cities across the country by the end of 2014.