Page updated: 05/08/2026
Background
A segmentation divides people into groups which are similar on chosen characteristics (such as demographics, needs, priorities, or common interests). It produces a set of groups where people in the same group are more similar to each other, but the groups are different. A geodemographic segmentaiton is calculated for where people live (based on theprinciple 'birds of a feather flock together'), so helps us understand the different types of communities in Bolton and how they are similar and different. We use it to tailor services and approaches so they are suitable for and appealing to the people who need or want them. Commercially available segmentations include CACI's Acorn, and Experian's Mosaic.
The free 'output area classification', based on 2021 census data, is included on the general purpose postcode lookup Geographies section of this website. Further information about the output area classification is available. The Geographic Data Service publishes a number of files supporting use of the output area classificaiton including pen portraits and an overview of how the classification is spread across the Bolton population.
The output area classification is only based on census data, and each output area (a very small administrative area) is given the same group, so less granular than commercial products such as Acorn and Mosaic. However it can otherwise be used in a similar way and is available for everyone to use. Some potential uses include: identifying if users of a service are more or less likely to be from a particular group, bringing service users to life with pen portraits.
Files to help you use the OA classification