Three customers can now use their existing bundled minutes when visiting the USA, Indonesia, Sri Lanka and Macau.
In August the network launched its Feel At Home service which lets customers user their standard bundled data, call and text allowances instead of paying international roaming charges.
It has now expanded the service to cover a total of 11 popular destinations.
Dave Dyson, Chief Executive of Three, said: “We want customers to get the most out of their devices at home or abroad. High roaming charges stop people enjoying their phones while they’re away and Feel At Home is the antidote to that.
Three has also provided an update on its 4G rollout.
The network has started enabling customers with a 4G-ready device to use the faster speeds when in a 4G coverage area.
It says the rollout will accelerate in January and that all customers with a compatible device will be able to access 4G at no extra cost by the end of Q1 2014.
Three aims to cover 50 cities with 4G by the end of 2014 and 98% of the population by the end of 2015.
Mr Dyson, said: “We are building a brand and network that encourages and enables customers to enjoy the mobile internet. Customers are using more data than ever on Three, far more than on any other network. As we add 4G capacity to the network, this experience will only get better.”