Three is launching a new app which will allow customers to talk and text using a Wi-Fi connection.
The broadband provider's Three inTouch application will be available to all contract, SIM-only and pay-as-you-go customers from early August.
Using Three customers' existing phone numbers, it allows them to make and receive calls and texts using their existing monthly allowance or prepaid credit.
According to Three, the app will improve the customer experience in places where there is typically no mobile signal.
Providing consumers have access to broadband via a Wi-Fi signal, they will be able to use their phones.
Three said it is focused on challenging the industry to make mobile better for everyone.
"We want to give customers a quality mobile experience and address the industry issues that frustrate them," it stated.
"We continue to look at ways of improving the experience we offer our customers."
Three's 3G network covers 98 per cent of the population, and the firm is aiming to offer 4G services in 50 cities and 200 towns by the end of this year.
By December 2015, Three is targeting 98 per cent 4G broadband coverage in the UK.