This page summarises methodological updates for Stats NZ's price indexes for the March 2026 quarter.
Consumers price index
We will publish Consumers price index: March 2026 quarter (CPI) on 21 April 2026.
Consumers price index - DataInfo+ describes the methodology used to produce CPI statistics and related metadata.
Methodology updates for the March 2026 quarter
Fees-free education impact
The first-year Fees Free scheme was replaced by the final-year Fees Free scheme on 1 January 2025. In the March 2025 quarter, we showed a 22.6 percent increase in tertiary and other post-school education prices as more students were paying the full study cost in 2025 (only students doing one-year courses were eligible for final-year free fees). In 2026 more students are eligible for final-year free fees (those doing one or two-year courses).
Treatment of unavailable fuel prices
Weekly fuel data for a small number of petrol stations was unable to be collected during some weeks in March due to fuel unavailability. As a result, unavailable fuel prices were imputed using the average price observed in the respective regions.
Prescription charges
The $5 prescription co-payment was reinstated on 1 July 2024. The impact of this was reflected in the pharmaceutical products class for the September 2024 quarter.
In the September 2024 quarter, we introduced more frequent collection of prescription fee data, and more accurately captured the effect of the Prescription subsidy scheme.
A household becomes eligible for the Prescription subsidy scheme once its members have collectively paid for 20 prescription items from 1 February each year. Using historical data, we have observed that over the course of a year, because of the 20-item cap, the average price the consumer pays for prescriptions falls approximately 60 percent by the end of January the following year.
In 2026, the prescription count began on 1 February 2026, in line with previous years.
Vehicle relicensing fee
In the March 2025 quarter, we did not include the price change for vehicle relicensing fees (an increase of $25 on 1 January 2025). We incorporated this price change using a catch-up movement in the June 2025 quarter. Because the price increase was applied as a catch-up movement, the annual movement for the March 2026 quarter will appear higher than it would have if the change had been captured at the time it occurred. This is because the March 2026 quarter annual movement will include the impact of the 1 January 2025 increase, as well as increases from 1 July 2025 and 1 January 2026.
Annual reweight of domestic airfares
In the March 2026 quarter, we implemented our annual reweight of the domestic airfares index, to ensure we accurately reflect current travel patterns. This process updates the weights of both main trunk and regional routes based on actual flight activity, as well as the different fare types.
New datasets
CPI basket items and weights
We have made the full CPI basket item list and the associated item-level weights available.
The weights can be accessed in the 'Consumers price index expenditure weights' Excel file under Download data.
These weights represent percentages of expenditure on each item bought for consumption purposes by households, as determined primarily by the 2022/2023 Household Expenditure Survey (which has now been replaced by the Household Income and Living Survey) and supplemented by other sources.
These weights were introduced in Consumers price index: March 2025 quarter, published on 17 April 2025, following the 2024 consumers price index review.
Consumers price index review: 2024 has more information.
Regional fuel weights
We have made the weights of the three different types of fuel (91, premium, diesel) available.
The weights can be accessed in the 'Consumers price index expenditure weights - fuel' file under Download data.
The figures on the CPI weights tab represent percentages of expenditure on each fuel type bought for consumption purposes by households, as determined primarily by the 2022/2023 Household Expenditure Survey (since replaced by the Household Income and Living Survey) and supplemented by other sources.
The figures on the Regional weights tab represent each region's share of the total population, which is then used to weight price changes.
Additional central and local government charges series
We have reviewed and updated which items are included in the central and local government charges series to ensure the series reflect current government charges. These updates will be available from the March 2026 quarter CPI release.
Unfortunately, due to limitations with the system used to calculate price indexes, the new series cannot be linked to the existing series, so will stand alone as a separate downloadable file.
The existing series will continue to be available in Infoshare and within our published CPI release Excel tables. The new series will be linked on (and replace) the existing series as part of the next CPI review.
The five new series are:
- Central government charges (brand new)
- Local government charges (brand new)
- Central and local government charges (new version of existing series)
- All groups less central and local government charges (new version of existing series)
- All groups less food, household energy, vehicle fuels, and government charges (new version of existing series).
The weights can be accessed in the 'Central and local government charges' file under Download data.
Update on monthly CPI
Monthly consumers price index - updates on progress summarises our approach and progress on development of the monthly CPI. We will continue to update it as we move towards delivering a monthly CPI.
Labour cost index
We will publish the March 2026 quarter labour cost index (LCI) on 6 May 2026.
Labour cost index - DataInfo+ gives general methodology used to produce labour cost index statistics and related metadata.
Business price indexes
We will publish the March 2026 quarter business price indexes (BPI) on 19 May 2026.
Business price indexes concepts - DataInfo+ gives general methodology used to produce business price index statistics and related metadata.
Producers price index annual reweight
In the March 2026 quarter, we will implement the annual producers price index (PPI) reweight. We reweight the PPI industry and commodity weights annually, using detailed product information sourced from the supply-and-use reconciliation we do each year in the national accounts. This release incorporates the new weights.
Producers price index weights has more information.
Enquiries
Lucy Happé
[email protected]
04 931 4600
