This is a best fit lookup between 2011 Output Areas (OA) and counties/unitary authorities as at 31 December 2021 in England. (File Size - 3 MB)Field Names - OA11CD, CTYUA21CD, CTYUA21NM, FIDField Types - Text, Text, TextField Lengths - 9, 9, 35
FID = The FID, or Feature ID is created by the publication process when the names and codes / lookup products are published to the Open Geography portal.
For more information and an overview of best-fitting follow this link - https://geoportal.statistics.gov.uk/datasets/f0aac7ccbfd04cda9eb03e353c613faa/about
