The UK rollout for the fifth generation mobile networks wasn't due to start until 2020, with some companies pushing for 2019, but the operator - which only launched in 2010 - have decided to upgrade their 3G to 4G from now to ensure that they're ready to set the 5G experience live from the beginning of next year.
CEO of BT's Consumer business, Marc Allera said: "Our customers want a fast and reliable 4G connection, and that's what we're working to give them. We are using the investment we made in 3G spectrum nearly 15 years ago to give customers today a great experience with the latest smartphones on 4G, and build our foundation for 5G in 2019. We're constantly evolving, and the customer experience of 5G will be dictated by the quality of the 4G network underneath."
Over the next six months, more than 500 mobile towers will be converted from 3G to 4G to enable maximum performance on this year's top smartphones.
Those set to get the upgrade include sites spread across London, Birmingham, Manchester, Bristol, Exeter, Nottingham, Edinburgh, Glasgow, Cardiff and Belfast.