Telecom's 4G LTE network is set to go live on a large part of its smartphone network in Auckland by October.
However, this will be months after Vodafone, launched its own equivalent network with plans to extend to Christchurch by next month and Wellington by the end of the year.
Telecom says its 4G network coverage will reach the other two main centres by Christmas.
Telecommunications Users Association Paul Brislen said he hopes there will be some pricing competition in the 4G market now that Telecom has come on board.
Telecom has chosen the Chinese firm Huawei of China to build the network.
Trials of the network by Huawei were held in Auckland and Rotorua. Alcatel Lucent, which built Telecom's troubled XT network, ran trials in Wellington.
