Kiwis who use their mobile phones a lot are paying much more than Australians.
A Commerce Commission report found New Zealanders who make lots of calls and use lots of data pay $48 per month on average, while Australians pay just $13 for the same services.
The report also found Kiwis are using far more data - up 69 percent, while the speed of our 4G internet ranks eighth in the world out of 88 countries.
The coverage isn't so good however, ranked 65th.
Out of New Zealand's mobile companies, the report found Skinny and 2 Degrees keep its customers happiest.
Telecommunications Commissioner Dr Stephen Gale said competition indicators were trending in a positive direction.
"We have three established mobile network operators in New Zealand and all are performing well on most measures of quality.
"However, there is room for improvement in some areas. Prices for large data plans are noticeably higher than Australia.
"Overall the study found that consumers are more satisfied with mobile than fixed fine services."