EE plans to bring 4G coverage to 95 per cent of the UK within the next four years.
The mobile operator's strategy focuses on eradicating so-called notspots - places where there is no 4G coverage - and pays particular attention to rural areas.
This includes 4G coverage that has been turned on in Shetland and the Isles of Scilly, which the company claimed demonstrates its "commitment to connect the furthest edges of the UK". Shetland is the most northerly region of the UK, while the Scilly Isles are the most southerly.
It comes after the UK's 4G coverage was found to lag behind the US and Europe, with EE providing the most coverage at 60 per cent, 10 per cent behind coverage in other countries.
The company is also rolling out Voice over LTE (VoLTE, also known as 4G Calling) across the UK, which it said will both allow users to continue accessing high-speed internet while they are on the phone, rather than being shifted onto 3G as currently happens.
It will also ensure people who are in 4G-only areas can make calls on their mobile phones.
"For the average smartphone user, not-spots aren't tolerated and 2G doesn't deliver what they need," said EE CEO Marc Allera.
Allera said mobile operators were "too used to saying 'no' to new coverage", but that with this announcement his company is "saying 'yes' with an ambition to go further than any operator has ever gone ... with the ultimate aim of covering the whole of the UK with 4G".
As well as announcing its 4G plans, EE also revealed it will bring all its customer service calls back to the UK and Ireland, after Ofcom fined it 1 million last year for customer service failures.
This will create 600 new roles, the company said, including 100 jobs spread across Plymouth, Merthyr Tydfil and North Tyneside, which will be created by the end of June this year. The remaining 500 will be announced in the second half of 2016.
"We've already seen a major boost in customer satisfaction by creating 1,400 new service jobs here since 2014," said Allera. "Now we're creating 600 additional jobs to handle all EE customer service calls in the UK and Ireland by the end of this year, providing the best possible experience for our customers."
