1. About the Standard Occupational Classification 2000: SOC 2000

The Standard Occupational Classification was first published in 1990 to replace both the Classification of Occupations 1980 (CO 80) and the Classification of Occupations and Dictionary of Occupational Titles (CODOT). SOC 90 has been revised and updated to produce SOC 2000.

The two main concepts of the classification remain unchanged:

  • kind of work performed – job

  • the competent performance of the tasks and duties – skill

There were two main sources of pressure to revise SOC 90: the need to improve alignment with the International Standard Classification of Occupations and the classification issues revealed by the research to develop the National Statistics Socio-economic Classification (NS-SEC).

Major influences on the nature and shape of the revision were the innovations associated with technological developments and, less directly, the redefinition of work reflecting the educational attainment of those entering the labour market.

The main features of the revision include:

  • a tighter definition of managerial occupations
  • a thorough overhaul of computing and related occupations
  • the introduction of specific occupations associated with the environment and conservation
  • changes linked to the upgrading of skills but the de-skilling of manufacturing processes
  • the recognition of the development of customer service occupations and the emergence of remote service provision through the operation of call centres

While an objective of the revision had been to maintain a reasonable degree of continuity with SOC 90, the main priority was to bring the classification up-to-date to reflect changes in society. This has resulted in significant changes to the classification.

Although there are still nine major groups, the top tier of the classification, their titles have been changed to reflect the change in content.

SOC 2000 major groups

  1. Managers and senior officials

  2. Professional occupations

  3. Associate professional and technical occupations

  4. Administrative and secretarial occupations

  5. Skilled trades occupations

  6. Personal service occupations

  7. Sales and customer service occupations

  8. Process, plant and machine operatives

  9. Elementary occupations

A considerable number of jobs have moved between unit groups, many between minor groups and more than a few between major groups. However, the numbers of groups in the tiers are similar.

Groups SOC 90 SOC 2000
Major groups 9 9
Sub major groups 22 25
Minor groups 77 81
Unit groups 371 353


One of the first decisions made on the structure of the classification was to bring the sub-major groups into the numbering system by having a four-digit classification.

Major group 2 Professional occupations
Sub major group 2a Science and engineering professionals
Minor group 20 Natural scientists
Unit group 200 Chemists


SOC 2000 example of the numbering system

| Major group | 2 | Professional occupations | | Sub major group | 21 | Science and engineering professionals | | Minor group | 211 | Natural scientists | | Unit group | 2111 | Chemists |

SOC 2000 – the use of trailing zeroes

When SOC 90 was revised to produce SOC 2000, one of the changes made to the standard occupational classification numbering system was to give the use of the trailing zero a particular meaning. This matched the convention used in the International Standard Classification of Occupations, ISCO 88.

Where a unit group is the only one within a minor group, its code number ends with a zero, for example:

Minor group 415 Administrative occupations: general
Unit group 4150 General office assistants/clerks


However, where a minor group has more than one unit group, the zero is not used.

Minor group 415 Administrative occupations: general
Unit group 4141 Telephonists
Unit group 4142 Communication operators


A last digit, or trailing zero, is used to indicate that there is only one unit group within the minor group or that coding could not be achieved at the more detailed level.

For instance, the use of code 4140 would indicate that the response could be coded to the minor group 414 but that there was insufficient information to assign one of the unit group codes 4141 or 4142. Using a zero in this way is rare.

One major disadvantage is that the derivation of the National Statistics Socio-economic Classification needs the official four-digit unit group code. Another disadvantage is that tables with counts at all levels of the occupation classification would require extra rows for codes such as 4140. If those records given code 4140 were included in the total for minor group 414, this figure would be greater than the sum of counts for unit groups 4141 and 4142.

SOC 2000 – the use of trailing digit “9”

Within each level of the classification, the trailing digit “9” is reserved for occupations “not elsewhere classified (n.e.c.)”. At the unit group level, these “n.e.c.” groups contain a mix of occupations, each of which are not found in sufficient numbers to merit their own unit group.

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2. Dissemination media and availability

Similar to SOC 90, SOC 2000 was published in two volumes.

Volume 1 describes the classification, lists the structure and gives detailed descriptions of the unit groups.

Volume 2 is the coding index: an alphabetical list of over 26,000 job titles, each one linked to a unit group of both the 1990 and 2000 editions of the classification.

The inclusion of two codes was a new feature for the occupation classification and has been introduced to help users make the transition from SOC 90 to SOC 2000, especially those wanting to assign codes from both classifications in one operation.

Both volumes were published at the beginning of June 2000. The SOC 2000 volumes can be downloaded from this page. The Institute for Employment Research has developed CASCOT coding software that can be used to assist with coding to SOC and the Standard Industrial Classification (SIC). More information on this can be found in the “External links” section of this page.

To achieve good-quality occupation coding, the following information is required:

  • a job title

  • a description of the work

  • the nature of business of the employer

  • higher qualifications and membership professional bodies (especially for accountants and engineers)

  • the number of employees in employing organisation for coding to the unit group for directors and chief executives (major organisations)

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3. Other classifications and definitions

SOC 1990

Some Office for National Statistics (ONS) data collections will code a block of records to both SOC 1990 and SOC 2000 to plot the relationship between the two classifications in their data.

The ONS Classifications and Harmonisation Unit receive the copies of the output and analyses from this SOC relationship work and hold them as a source of information for users of SOC.

International Standard Classification of Occupations (European variant) (ISCO 88 COM)

A mapping of SOC 2000 unit groups to unit groups in ISCO 88 COM is available from the Classifications and Harmonisation Unit.

Social classifications

SOC 1990 was used to derive the two government social classifications: social class based on occupation and socio-economic group.

The National Statistics Socio-economic Classification (NS-SEC) is replacing both of these classifications and SOC 2000 is used to derive the NS-SEC.

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