For participants resident in England, this field contains the County and District codes, London Boroughs, Non-metropolitan districts, local authorities and metropolitan districts and unitary authorities (nowadays collectively referred to as Local Authority Districts) based on 2001 boundaries and the participant's home address at baseline.
For participants resident in England, this field takes the form NNAA, where the first two numeric characters represent the county, and the second pair of characters represents the district.
For participants resident in Wales, this field contains the Welsh unitary authority at the 2001 Census.
For participants resident in Scotland, this field contains the Council area, and takes the form [NN].
Office for National Statistics, 2001 Census: Digitised Boundary Data (England and Wales) [computer file]. UK Data Service Census Support. Downloaded from: https://borders.ukdataservice.ac.uk
General Register Office for Scotland, 2001 Census: Digitised Boundary Data (Scotland) [computer file]. UK Data Service Census Support. Downloaded from: https://borders.ukdataservice.ac.uk
The information is licensed under the terms of the Open Government Licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 If you are using these data in your analyses please ensure you abide by the licence terms.