Broadband internet provider Wired Country will introduce a data cap for the first time on its wireless packages, beginning on Tuesday.
General manager Mike Lancaster said the cap was being introduced because abuse of uncapped plans by a minority of users was reducing performance for others.
"Those good at tuningtheir machines could set themselves to hog their entire allocation 24 hours a day if they wished, and basically exclude others from getting to use that chunk of capacity," Lancaster said.
Some customers were using more than 200 gigabytes a month.
The new caps will range from 10GB to 30GB a month. Beyond those limits, connection speeds will be throttled back, to 64Kbit/s, in the same way that Xtra imposes caps on its JetStream offerings.
Businesses will be capped at up to 50GB. The fibre network remains uncapped.
Lancaster said the caps had been set after months of research and consultation with customers.
"We know the usage of every single customer connected to our network and we've chosen the caps so they affect only a very small percentage and everyone else can behave exactly as they are behaving now."
Internet provider Ihug will be one of those affected by the change. The company's marketing manager, Rob Anderson, said less than 10 per cent of users would be affected, and caps of 10GB to 30GB were "still a huge amount of data".
Ihug offers plans with a mixture of uncapped national data and capped international data.
Anderson said plans would be simplified over the next month to match Wired Country's caps.
Lancaster said a capped plan with excess data charges for exceeding the limit would also be introduced.
Capped plan users would receive a warning as they approached their limit.
Telecommunication Users Association chief executive Ernie Newman said the association encourages uncapped services but he complimented Wired Country for the "reasonable safeguard" of warning customers who approach limits.
"There is some inevitability to the concept of caps and the good thing about this one is it will only affect the really extreme, high-volume user."
