One NZ is increasing its pricing on a broad range of mobile plans from September 24 by $5 a month - with the telco siting infrastructure costs associated with a 24% surge in data usage.
Additionally, MyFlex prepay data pricing is increasing by $1 a month.
The mobile rises follow a round of price increases at the same level for One NZ broadband customers in April.
Rival Spark bumped up prices mid-year.
One NZ’s steps to boost its capacity include its ongoing 5G upgrade and its purchase of radio spectrum from Dense Air in May, which chief executive Jason Paris described as the equivalent of “an extra lane on the motorway”.