The firm will announce to its 27m customers they will now be able to access the network of both brands, which it says will allow them to use mobile services over a greater geographical area.
The firm yesterday branded the move the “single biggest transformation of mobile coverage since the birth of mobile”. Customers will be asked to register for the service but will not be charged.
Tom Alexander, chief executive of Everything Everywhere, said: “Today’s switch-on is the culmination of a hugely complex project. But the result is simple – our customers now get two networks for the price of one.”