Index of Production, UK: March 2025

• Production output for Quarter 1 (Jan to Mar) 2025 was estimated to have increased 1.1%, compared with Quarter 4 (Oct to Dec) 2024; this is the first rise in the quarterly series since Quarter 1 2024.

• "Manufacturing" (up 0.8%) was the main contributor to the quarterly rise in Quarter 1 2025, supported by smaller positive contributions from "water supply and sewerage" (up 4.0%) and "electricity and gas" (up 1.8%); this was partially offset by a decrease in "mining and quarrying" (down 0.5%).

• The increase in manufacturing output during Quarter 1 2025 saw rises in 10 of its 13 subsectors.

• The largest positive contributions to the quarterly rise in manufacturing during Quarter 1 2025 came from "transport equipment" (up 2.7%) and "machinery and equipment not elsewhere classified" (up 3.8%).

• Monthly production output was estimated to have decreased 0.7% in March 2025; this follows a rise in February 2025 (up 1.7%) and a fall in January 2025 (down 0.4%).

• The fall in monthly output in March 2025 resulted from decreases in "manufacturing" (down 0.8%), "mining and quarrying" (down 1.2%), and "electricity and gas" (down 0.7%); these were partially offset by an increase in "water supply and sewerage" (up 0.8%).

• The largest of the seven negative contributions to manufacturing output in March 2025 came from similar-sized decreases in "computer, electronic and optical products" (down 8.4%) and "basic pharmaceutical products" (down 5.8%); this is mainly a fallback, following strength from both subsectors during February 2025, when they increased by 9.8% and 4.4%, respectively.

All data related to the Index of Production (IoP) are available on our Related data page.

The Index of Production (IoP) uses data from a variety of sources. It is calculated by taking turnover and removing the effect of price changes, or by using direct volume estimates.

Most of these data are collected as "turnover values" through the Monthly Business Survey (MBS). Direct volume series are also collected by the Department for Energy Security and Net Zero (DESNZ), and the International Steel Statistics Bureau (ISSB) for steel industries.

The MBS is fully online. Business owners can log on from any location and submit their data at an appropriate time.

From January 2018, Value Added Tax (VAT) data have also been included for 64 production industries for small- and medium-sized businesses. More information is available in our VAT turnover data in National Accounts: background and methodology.

A comprehensive list of the IoP source data can be found in our Gross domestic product (GDP) data sources catalogue.

Response rates for March 2025

MBS response rates were 71.8% for March 2025, based on forms returned. This accounted for 83.4% of total turnover coverage of the sample population. For further information, see our current and historical MBS (production) response rates dataset.

Quality and methodology

The data reported in IoP bulletins and datasets are estimates that are subject to uncertainty, such as sampling variability and non-sampling error. More information is available in Section 2 of our Uncertainty and how we measure it for our surveys web page.

More quality and methodology information (QMI) on strengths, limitations, appropriate uses, and how the data were created is available in our Index of Production, UK QMI.

Accredited official statistics

These accredited official statistics were independently reviewed by the Office for Statistics Regulation in April 2014. They comply with the standards of trustworthiness, quality and value in the Code of Practice for Statistics and should be labelled "accredited official statistics".

Revisions to Index of Production

In line with the National Accounts Revision Policy, this release gives data for March 2025, with January and February 2025 also open for revision.

Pausing of Producer Prices publications

Our producer prices publications are currently paused, as described in our update published on 11 April 2025. Our quality assurance identified a problem with the chain-linking methods used to calculate the Producer Price Index (PPI) and Services Producer Price Indices (SPPI) during work to improve the systems used to create the PPI and SPPI indices.

Our investigations so far have concluded the problem affects the period from December 2008 onwards. However, investigations suggest that the main effect on annual producer price inflation rates was in 2022 and 2023, because of the large movements in relative prices during that period. 

These detailed price data are used within IoP and gross domestic product (GDP) calculations. This may lead to effects on the level of some industries. Revisions to estimates are likely in 2022 and 2023. At an aggregate level for GDP, these revisions should be offsetting to an extent, while taken alongside regular data deliveries. Early indications suggest that there will not be a notable change in the recent economic trends seen in these data, but we will update users once more information becomes available. We do not plan any changes to the publication timetable for IoP. We will continue to use PPI and SPPI estimates compiled under the current methodology in these publications until updated methods and data are available.

Seasonal adjustment

The monthly estimates of IoP are seasonally adjusted. Seasonal adjustment is the process of removing the variations associated with the time of year, or the arrangement of the calendar, from a data time series.

IoP estimates, as for many data time series, are difficult to analyse using raw data because seasonal effects dominate short-term movements. Identifying and removing the seasonal component leaves the trend and irregular components.

We use the X-13-ARIMA-SEATS approach to seasonal adjustment. Seasonal adjustment parameters are monitored closely and are regularly reviewed. For more information, please see our seasonal adjustment methodology page.

In our IoP estimates, seasonal adjustment is applied at the industry level. The seasonally adjusted series are aggregated to create estimates by sector and total IoP output. As part of our quality assurance approach, residual seasonality checks are regularly completed by our time series analysis team on both the directly seasonally adjusted series and the indirectly derived aggregate time series.

This topic is explored further in our Assessing residual seasonality in published outputs methodology published 9 May 2025.