Deciding to group logos by region(and country) made me wonder about existing regions. Sure enough, the [ONS](https://www.ons.gov.uk/methodology/geography/geographicalproducts/namescodesandlookups/namesandcodeslistings/namesandcodesforadministrativegeography) use regions, and after navigating some pretty detailed and technical articles I found what are called GSS Geographical Codes.

England by region

South West

South East

West Midlands

East Midlands

London

Yorks & Humber

North East

North West

East

Wales

Scotland

Irish