New Zealand's consumer prices rose at a faster pace than reported in the September quarter, with Statistics New Zealand discovering it mucked up the way it calculated Accident Compensation Corp's motor vehicle licensing fees in the period.

The consumers price index rose 0.3 per cent in the three months ended Sept. 30, ahead of the 0.2 per cent pace originally reported on Oct. 18, which was itself above Reserve Bank expectations for a 0.1 per cent increase. The annual pace was revised up to 0.4 per cent, twice the 0.2 per cent annual pace reported last month, and closer to the bottom of the RBNZ's 1 per cent-to-3 per cent target band.

"The changes were required to correct a manual processing error discovered by Statistics NZ. The error affected prices for vehicle relicensing fees, within the transport group," the government department said in a statement. "Statistics NZ is confident that the correction only affects the September 2016 quarter index numbers, as it occurred in our measurement of lower ACC levies for light vehicles that came into effect during the quarter."

The government department has already told the Reserve Bank ahead of this week's monetary policy statement and the Treasury, which is preparing the half-year economic and fiscal update.


"Following our protocols for errors, Statistics NZ has decided to correct the CPI now to ensure our customers have the best possible information to inform their decisions," it said.

The revision means prices for the transport sector shrank 1.9 per cent in the quarter, not the 3 per cent originally report, for an annual decline of 5.6 per cent as opposed to 6.7 per cent. The transport sector was the biggest drag on prices in the quarter due largely to the reduction in vehicle relicensing fees that kicked in on July 31. Cheap petrol and new and used cars have also been weighing on the sector.