Index of Production, UK: September 2023

• We estimate that monthly production output has shown no growth in September 2023; this follows a fall of 0.5% in August 2023 (revised upwards by 0.2 percentage points).

• The monthly output for September 2023 has shown no growth (0.0%), with two of the four production sectors reporting increased output; "water supply and sewerage" was the main positive contributing sector (1.4%), with a smaller contribution from "manufacturing" (0.1%), offset by falls in "mining and quarrying" (2.2%) and "electricity and gas" (0.5%).

• Monthly manufacturing output increased by 0.1%, with increases in 5 of its 13 sub-sectors during September 2023; most notably, "manufacture of computer, electronic and optical products" and "manufacture of machinery and equipment" increased 2.8% and 2.7%, respectively.

• Looking at the longer-term profile, quarterly production output growth for Quarter 3 (July to Sept) 2023 saw no growth when compared with Quarter 2 (Apr to June) 2023; this follows 1.2% quarterly growth in Quarter 2 2023.

• The main positive contributing sectors over Quarter 3 2023 were "manufacturing" and "mining and quarrying", which increased by 0.1% and 0.6% respectively; these rises were offset by "water supply and sewerage", which declined by 0.8%.

• Further analysis of the effect on our monthly Index of Production (IoP) estimate is available in our Gross domestic product (GDP) monthly estimate, UK: September 2023 bulletin, published 10 November 2023.

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

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

The Office for National Statistics' (ONS) MBS is fully online. Business owners can log on from any location and submit their data at an appropriate time. Most other data in the IoP come from the DESNZ, and therefore will be less affected than the survey data.

From January 2018, Value Added Tax (VAT) data have also been included across 64 production industries for small and medium-sized businesses. For more information, see 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.

Quality and methodology 

More quality and methodology information on strengths, limitations, appropriate uses, and how the data were created is available in our UK IoP Quality and Methodology Information (QMI).

Additional bank holiday in May 2023 for the Coronation of King Charles III  

There was an additional bank holiday for the coronation of King Charles III on Monday 8 May 2023. While adjustments are made for regular calendar effects, there was no explicit adjustment for this event. However, the timing of the bank holiday indirectly affects the number of trading days, which could affect GDP estimates positively or negatively, depending on the sector. This should be taken into account when interpreting monthly, and three-month movements over recent months since May 2023.  

Revisions to Index of Production

In line with our National Accounts Revision Policy, this release gives data for September 2023 for the first time with July and August 2023 also open for revision.  

Updates to monthly gross domestic product methods and data sources in Blue Book 2023

A number of changes have been made to the methods and data sources used in compiling monthly GDP and output approach to measuring GDP estimates as part of Blue Book 2023.

For further information on the updates please see Section 10: Measuring the data in our GDP monthly estimate, UK: September 2023 bulletin.

Office for Statistics Regulation review of gross domestic product

The Office for Statistics Regulation (OSR) completed a review of the practices around the preparation and release of information about revisions to estimates of GDP in our Impact of Blue Book 2023 article released on 1 September 2023. This will cover the following: 

• processes and quality assurance in making revisions to GDP   

• potential improvements to early estimates of GDP enabled through enhanced access to data   

• communication of revisions to GDP, the story behind the most recent set of revisions in particular, and uncertainty in early estimates of GDP