This dataset is a lookup file linking unit postcodes to Broad Rental Market Area (BRMA) boundaries for the UK. BRMAs are the spatial areas used for the administration of Housing Benefit or Local Housing Allowance. There are 200 BRMAs in total. BRMA boundaries were collected from publicly available datasets. For Great Britain, postcodes were linked to BRMAs using Office for National Statistics (ONS) postcode centroid lookups. For Northern Ireland, the lack of open postcode data required the use of a workaround. Full details on process here: https://github.com/nick-bailey/Postcode-to-BRMA-lookup. In v2.2, we correct an error from the previous version which meant that West Dunbartonshire BRMA had been omitted with postcodes in that zone wrongly attributed to neighbouring BRMAs.