This file contains the digital vector boundaries for Counties and Unitary Authorities (also known as Upper Tier Local Authorities) in the UK, as at 31 December 2017.
The boundaries available are:
Full resolution - extent of the realm (usually this is the Mean Low Water mark but in some cases boundaries extend beyond this to include off shore islands);
Full resolution - clipped to the coastline (Mean High Water mark);
Generalised (20m) - clipped to the coastline (Mean High Water mark);
Super generalised (200m) - clipped to the coastline (Mean High Water mark) and
Ultra generalised (500m) - clipped to the coastline (Mean High Water mark).
Contains both Ordnance Survey and ONS Intellectual Property Rights.