This page summarises methodological updates for Stats NZ’s price indexes for the September 2026 quarter.
Consumers price index
We will publish Consumers price index: September 2026 quarter (CPI) on 22 October 2026.
General methodology
Consumers price index – DataInfo+ describes the methodology used to produce CPI statistics and related metadata.
New water entities
Since 1 July 2026, Tiaki Wai (serving Porirua, the Hutt Valley, and Wellington), IAWAI (serving Hamilton and Waikato), and Selwyn Water Limited (serving Selwyn) have separated water services charges from council rates. Following these changes, Stats NZ now collects water service charges directly from these entities. For CPI purposes, metered water charges will continue to be included in the water rates item, consistent with historical treatment. Other water service charges have been added back into the local authority rates item, as the 2024 CPI reweighting treated council rates in these regions as inclusive of these services. This maintains consistency with the expenditure classification and weights used in the current CPI.
Early childhood education index unchanged by FamilyBoost estimate
Inland Revenue has provided data on the rebate households are expected to receive for early childhood education in 2026/27 through the FamilyBoost scheme. The expected rebate is approximately $168 million, unchanged from the 2025/26 estimate that was applied in the CPI for the September 2025 quarter. As the expected rebate is unchanged from the previous year, there is no impact on the CPI movement. The early childhood education index will reflect any other price changes recorded for early childhood education.
Shift to administrative data for long-distance bus fares
Administrative data for long-distance bus fares will be incorporated into the CPI from the September 2026 quarter, replacing survey and online data collection. The new data source provides a broader and more representative measure of prices paid by consumers than the previous point-in-time collection approach.
Impact of vehicle relicensing fee timing error on annual CPI inflation in March 2025 and March 2026 quarters
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 was higher than it would have been if the change had been captured at the time it occurred. This is because the March 2026 quarter annual movement included the impact of the 1 January 2025 increase, as well as increases from 1 July 2025 and 1 January 2026.
Consumers price index – DataInfo+ will be updated to include information on this issue and its impact on annual CPI inflation.
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 this page with our progress on delivering a monthly CPI.
Household living-costs price indexes
We will publish Household living-costs price indexes: September 2026 quarter (HLPI) on 30 October 2026.
Household living-costs price indexes (HLPIs) – DataInfo+ gives general methodology used to produce household living-costs price indexes statistics and related metadata.
Labour cost index
We will publish the September 2026 quarter labour cost index (LCI) as part of Labour market statistics: September 2026 quarter on 4 November 2026.
Labour cost index – DataInfo+ gives general methodology used to produce labour cost index statistics and related metadata.
Business price indexes
We will publish Business price indexes: September 2026 quarter (BPI) on 18 November 2026.
Business price indexes concepts – DataInfo+ gives general methodology used to produce business price index statistics and related metadata.
Enquiries
Prices and deflators team
[email protected]
04 931 4600
