High-spending households were hit by rising airfares and rental car costs in the December quarter while lower-spending ones got some relief from cheaper vegetables.
High-spending households saw their cost of living lift 0.2 per cent on the quarter while the lowest-spending ones saw it dip 0.1 per cent, Statistics New Zealand said.
"Low-spending households don't typically take many overseas trips or hire rental cars, so those price increases had little impact on them," consumer prices manager Caroline White said.
Low-spending households benefited the most from cheaper vegetables in the last three months of 2018, she said. According to White, "low-spending households typically spend more of their household budget on vegetables than other groups".
In addition to vegetables, living costs for low-spending households were brought down by price falls for soft drinks, waters, juices and petrol, she said. These falls were offset by price rises in rents and meat and poultry.
Annual inflation for high-spending households, meanwhile, increased by just 1.8 per cent in calendar year 2018, kept low by cheaper airfares and a drop in tertiary education costs.
It was the lowest rate for any household group, despite the higher quarterly inflation in December.
For all households, annual inflation was up 2.1 per cent, outpacing the consumers price index which rose an annual 1.9 per cent in the December quarter.