Relationships of administrative areas

The Boundary-Line product supplies the administrative area relationships.

A district is a division of a county; a civil parish is a division of a district. A county is divided for voting purposes into electoral divisions (EDs) and a district is divided for voting purposes into district wards.

Unitary authorities

With the introduction of unitary authorities, there are now two- and three-tier local government hierarchies. The three-tier system remains unchanged. The two-tier system has unitary authorities replacing the county and district levels of administration.

Unitary authorities may be divided into civil parishes or communities (except in Scotland), and unitary authority wards or unitary authority EDs for voting purposes. In Wales, the voting area is the unitary authority ED; in Scotland it is the unitary authority ward and in England it is the unitary authority ward or unitary authority ED.

Metropolitan districts

England also has metropolitan districts; these have no county administration. These districts are divided for voting purposes into metropolitan district wards.

Greater London Authority and London borough

With the introduction of the regional government for London, in this document called the Greater London Authority, the proportional representation voting area for this new administration is the Greater London Authority Assembly constituency. The existing London borough structure also has a relationship with the new Greater London Authority and each London borough is divided for voting purposes into London borough wards.

Scottish Parliament constituency and electoral regions

Scotland is divided into parliamentary constituencies for voting purposes to elect Members of the Scottish Parliament (MSPs). The Scottish Parliament electoral region is a grouping of Scottish Parliament constituencies.

Welsh Parliament constituency and electoral regions

Wales is divided into parliamentary constituencies for voting purposes to elect parliamentary members (MS) to the Welsh Parliament. The Welsh Parliament electoral region is a grouping of Welsh Parliament constituencies.

English regions

The exit of the United Kingdom from the European Union on 01 January 2021 resulted in the repeal of the European Regions as active electoral areas. For the purposes of Boundary Review, the original European Regions in England have been retained as nine English Regions in the Boundary-Line product. A frozen layer of European Region features, preserved as of 01 April 2021, is available as a supplementary historical dataset.

Westminster (parliamentary) constituency

England, Scotland and Wales are divided into parliamentary constituencies for voting purposes to elect members (MPs) to the Westminster Parliament. Parliamentary constituencies are made up of combinations of wards (or electoral divisions in Wales).