5 minutes

The Geodemographic Classification released as part of the census is the bedrock for most commercial geodemographic solutions. These classifications are sometimes referred to as OAC (Output Area Classifications) as they are released at an Ouptut Area level. We’ve outlined the groups or clusters that form the Geodemographic Classification below. These can also be mapped to postcodes to give you an informal view of each group or cluster’s characteristics. The OAC uses a hierarchical classification system divided into three tiers:

  • supergroups
    • groups
      • subgroups

These provide geodemographic information at the lowest census area i.e. Small Areas (SAs) in Northern Ireland and Output Areas (OAs) in England, Scotland and Wales. The goal of the Geodemographic Classification tiers is to provide a concise and convenient description of an area, with relation to household composition, employment patterns, demographic structure, housing, and socioeconomic position. In practice, however, there is a degree of variability to be expected with all characteristics at all tiers.

Understanding Supergroups

The Supergroup is the top tier of the Geodemographic Classification hierarchy, there are eight supergroups that form this tier. Supergroup descriptions by their very nature tend to be somewhat general and broad, reflecting the size of this classification tier. Additionally, any supergroup description that mentions “average” relates to the average characteristics for the United Kingdom. Supergroups generally make comparisons with the UK as a whole, unless otherwise stated.

Understanding Groups

The middle tier is the group Geodemographic classification, and there are 26 groups in total. Groups can be discerned by the letter and number in their descriptions, and give a more in-depth description of the characteristics of the area than their supergroup counterparts. The OAC uses a top-down classification system, meaning that group description numbers will match those of their parent supergroup, ensuring easy classification. Each supergroup produces two or four groups. In the case of groups, a mention of “average” refers to the average value of the linked supergroup, not the national average. Unless the group description mentions otherwise, group comparisons refer to their parent or linked supergroup.

Understanding Subgroups

At the OAC’s bottom tier, we find the subgroups, there are 76 subgroups in total. Each subgroup gets an identifier in the number, letter, number format (nxn). These descriptions link the subgroup to the parent group and to the parent supergroup characteristics. Any comparisons made in the subgroups compare to the parent group tier. All subgroups have the same letter and number as their parent group, forging traceable links between all tiers. Each group can produce two or four subgroups. Any subgroup description that refers to an “average” means the “average” of the linked parent group only, not the national average or parent supergroup “average.” Subgroups make all of their comparisons with the linked group unless their description specifically states otherwise.

Names and Descriptions

All of the names and descriptions of the eight supergroups, twenty-six groups and seventy-six subgroups are designed to give a more in-depth insight than you’d get with statistical outputs of cluster analysis. Although these groupings may not accurately reflect the entire population’s characteristics, they do accurately represent the general characteristics of the majority of the targeted populations. The names and descriptions are colour-coded to demonstrate their status of supergroup, group or subgroup tier.

Explore The OAC Classifications


There are several terms and phrases in a description that may require a more thorough description and clarification. Old EU Countries – This refers to the fifteen pre-2004 accession and expansion countries of the UK, Belgium, Austria, Finland, Denmark, Greece, Irish Republic, Germany, France, Netherlands, Portugal, Luxembourg, Sweden, Italy and Spain. We could refer to these countries as original European Union members. New EU Countries – This refers to the ten post-2004 accession and expansion countries of Estonia, Bulgaria, Lithuania, Czech Republic, Hungary, Slovakia, Latvia, Romania, Poland and Slovenia. Industries– The Standard Industrial Classification of 2007 (SIC 2007) defines a wide range of industrial categories. These include the following:

  • Accommodation or food service activities and industries
  • Administrative or support service activities and industries
  • Agriculture, forestry and fishing, and all related fields
  • Energy, water or air conditioning supply industries
  • Financial, insurance or real estate industries
  • Information and communication or professional, scientific and technical activities and industries
  • Manufacturing and secondary industry
  • Mining, quarrying or construction industries
  • Transport, logistics or storage industries
  • Wholesale and retail trade; repair of motor vehicles and motorcycles industries

In order to improve readability, the descriptions of the supergroup, group and subgroup typically abbreviate the descriptions we listed above. For example, instead of using the full description of “financial, insurance or real estate industries,” it would say financial industries.

Overcrowding – This refers to the percentage of the population with fewer rooms than required.

Qualifications– This refers to different present and past qualifications including:

  • Level One – GCSEs (grades D through G) and diplomas (BTEC, City & Guilds)
  • Level Two – GCSEs (grades A* through C) and O Levels (grades A through C)
  • Level Three – A Levels (grades A through E) and AS Levels
  • Level Four and Up – Higher National Certificates (HNCs) and degrees