Three UK has added the USA to its Feel at Home plan which will mean customers travelling there won't have to pay extra to use their mobile phone.
The move by will be seen as a major step towards the elimination of high roaming charges for mobile phone users by offering its customers the ability to use call, text and data allowances in the US for no extra cost.
The move is part of Three's Feel at Home plan, which now includes 11 countries, but the addition of the USA is by far the most significant move to date.
In August the network made the bold move to launch the Feel at Home service, challenging other UK networks to provide similar deals to its customers. Three was able to make the move because its parent company, Hutchison Whampoa, owns carriers in those countries.
The USA move however marks the first time the company is launching the service using another company's network. Three UK customers will automatically roam on AT&T and T-Mobile networks when visiting the States on holiday or for work.
Commenting on the move, Dave Dyson, Chief Executive of Three, said: "Adding the USA to the mix is great news for our customers and shows our commitment to giving them the best experience in what is a popular destination. We plan to add more countries to the mix soon."
Three also announced the addition of Indonesia, Sri Lanka and Macau to the deal, joining Austria, Australia, Denmark, Hong Kong, Italy, the Republic of Ireland and Sweden which are already included in the plan.
EU eliminating roaming
The move comes at a time when the European Union is pushing for the complete elimination of all roaming charges within its borders, a push led by Europe's top telecoms regulator Neelie Kroes.
The proposals for a new telecoms law were adopted by the European Commission in Spetmeber but will need to be approved by the European Parliament and individual member states before being ratified.
The proposals could come into law as soon as the middle of 2014, Kroes believes.
Three UK, as well as launching its extended Feel at Home service, has detailed how it will roll out its 4G service.
It announced that it had turned on 4G at the beginning of this week, upgrading customers who already have a 4G-ready device. Three is unique in the UK by offering its customers access to the faster 4G network without additional cost.
It says all customers with a compatible device will be able to access 4G at no extra cost by the end of March next year, but only when they are in an area with 4G coverage.
EE leads the way in terms of 4G coverage, announcing on Wednesday that 160 towns and cities will be covered by the end of the year. O2 and Vodafone are playing catch-up having launched their 4G services almost a full year after EE.
Three aims to cover 50 cities with 4G by the end of 2014 and 98% of the population by the end of 2015.