This dataset contains grid references for the 2001 frozen postcode boundaries. Each individual postcode polygon holds a grid reference. Grid references have been assigned by NRS, choosing the building nearest to the centre of the most populous part of the postcode, or the grid reference is from Gridlink®.

Workplace Zones (WZs) are a new output geography, initially produced using workplace data from the 2011 Census for England and Wales rather than the UK as a whole. They are designed to supplement the Output Area (OA) and Super Output Area (LSOA and MSOA) geographies that were introduced with the 2001 Census, and have been constructed from OAs, or sub-divisions of these called postcode-level building-blocks (PCBBs). While OAs are designed to contain consistent numbers of persons based on where they live, WZs are designed to contain consistent numbers of workers, based on where people work. Following publication of WZs for England and Wales, coverage has subsequently been extended to include Scotland and Northern Ireland using 2011 Census data to create a UK set of WZs produced by the Office for National Statistics (ONS) on behalf of National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA). WZs are designed to be a more suitable output geography for publishing workplace statistics.