2degrees has secured its millionth customer.
The mobile phone provider, which has been operating for three years, says it now has 21% of the mobile phone market.
The company started out in the prepay market in August 2009, acquiring 206,000 customers in its first six months of training.
Last year it launched its 3G network and a post-pay service and now it's providing services to businesses, as well as individual consumers.
Chief executive Eric Hertz says lower prices are the main factor in winning customers.
"For example, we were virtually half the price of what 70% of the market was paying here on prepay and as we've launched pay-monthly postpay product we're 20-30% lower, so it's delivered real value and I think people really appreciate value."
New Zealand's third mobile operator has 97% coverage throughout the country and operates 35 stores, employing more than 700 staff.