The Office for National Statistics has announced its complete consumer price index development plan for September 2025, which indicates some ambitious changes to revamp the way inflation is measured in the UK. The new roadmap focuses on the integration of grocery scanner data in March 2026, the elimination of legacy systems, and the implementation of COICup 2018 to maximize the accuracy of the statistics.
Grocery scanner information integration drives change priorities
The Office for National Statistics (ONS) has a continuous research and development programme to advance and sustain its consumer price inflation statistics. The development plan will make sure that the statistics remain user-friendly, utilize new and innovative approaches and sources of information, and adhere to best practices in the international standard. Provision of quality consumer price information is a fundamental focus of the ONS, especially after the results of the Devereux Review of Office performance and culture and the strategic direction indicated by the Economic Statistics Plan (ESP).
We hope to publish the data of grocery scanners in our consumer price inflation bulletin in February 2026 (published in March 2026), as explained in our Introducing grocery scanner data into consumer price statistics methodology. We will also run scanner data in parallel during one year, and then incorporate it into live production in March 2026, with the new data taking up 50% of the market share. In the remaining 50 percent of the grocery market, our prices will still be collected manually in-store and online.
Complex quality assurance guarantees standards of statistical accuracy
We have already provided many of the transformational changes that were proposed in consumer price statistics. We have currently generated an indicative impact analysis of grocery scanner data in April 2025, though due to the need for complex data and methods, as well as due to the significance of such statistics, further quality assurance is necessary to ensure the data is of the highest quality.
Legacy system removal addresses technological infrastructure challenges
Another area we are currently working on is risk reduction associated with the use of the legacy technology (as mentioned in the ESP), which is still present in the end-to-end processing system in some regions. This restricts our capacity to adapt our systems. We are gathering certain data now with legacy technology and are processing some of the data we have gathered manually with other legacy systems. In the next 12 months, we will start migrating a larger part of our data collection operations off of legacy technology into a cloud-based strategic platform.
Although great progress has been achieved in recent years, consumer prices are still dependent on old technology to play a key role in our production process. This constrains our flexibility in updating our systems. Specifically, we are now gathering some data internally (central) in spreadsheets and other old systems. Our other legacy systems are also used to process some of the data that we have collected manually.
Implementation of COICOP 2018 needs interdomain coordination
COICOP offers the framework of the Consumer Prices Index with that of owner-occupier housing costs (CPIH) and the Consumer Prices Index (CPI). It also forms the basis of the estimation of Household Final Consumption Expenditure (HHFCE) estimates in the System of National Accounts, on the CPIH and CPI baskets that are weighted on. The United Nations in 2018 completed a revision of the COICOP framework, which meant that UK consumer price statistics had to be reorganised accordingly.
The ONS September 2025 consumer price development plan is a crucial step in the modernisation of UK statistics, with a balance between technological progress and rigorous methods. The bold schedule of data integration of scanners in the grocery business and the elimination of the legacy system reflect seriousness in improving the accuracy and efficiency.