The National Statistics Socio-economic Classification (often abbreviated to NS-SEC) is the official socio-economic classification in the United Kingdom.
[1][2] It was developed using the Standard Occupational Classification 1990 (SOC90) and rebased on the Standard Occupational Classification 2000 (SOC2000) before its first major use on the 2001 UK census.
The NS-SEC was rebased on the Standard Occupational Classification 2010 prior to the 2011 UK census and it will be further rebased on the new Standard Occupational Classification 2020 for use on the 2021 UK census.
It has 14 operational categories, with some sub-categories, and is commonly used in eight-class, five-class, and three-class versions.
[5] Only the three-category version is intended to represent any form of hierarchy.