Mobile phone operator EE is aiming to bring 4G to 95% of the UK landmass by 2020 as well as relocating its customer services to the UK and Ireland.
In 2015, the firm was fined £1m ($1.4m) by communications watchdog Ofcom over customer service failings.
The network will also switch on high-speed 4G in the Shetland Islands and the Isles of Scilly this week.
Currently, 4G coverage is measured as a percentage of the population rather than geographically.
That means mobile networks typically focus on areas where lots of people live rather than extending geographical reach of their services.
