ICCT and OSCL activities are administered in the UK and Ireland through the following 14 Regions:

The non-metropolitan counties of Bedfordshire, Berkshire, Buckinghamshire and Oxfordshire. The unitary authorities of Bracknell Forest, Milton Keynes, Reading, Slough, West Berkshire, Windsor & Maidenhead and Wokingham; City of Westminster; and London Boroughs of Barnet, Brent, Camden, Ealing, Hammersmith & Fulham, Harrow, Hillingdon, Hounslow and Kensington & Chelsea.

The non-metropolitan counties of Cambridgeshire, Essex, Hertfordshire, Norfolk and Suffolk; the unitary authorities of Peterborough, Southend-on-Sea and Thurrock; City of London; and the London Boroughs of Barking & Dagenham, Enfield, Hackney, Harringey, Havering, Islington, Newham, Redbridge, Tower Hamlets and Waltham Forest.

The non-metropolitan counties of Derbyshire, Leicestershire, Lincolnshire, Northamptonshire and Nottinghamshire; the unitary authorities of Derby, Leicester, North East Lincolnshire, North Lincolnshire, Nottingham and Rutland.

Northern Ireland and the Republic of Ireland.

The non-metropolitan counties of Gloucestershire, Shropshire and Worcestershire; the unitary authorities of Bristol, Herefordshire, South Gloucestershire and Telford & Wrekin.

The non-metropolitan counties of Cumbria, Durham and Northumberland; the metropolitan county of Tyne & Wear; the unitary authorities of Darlington, Hartlepool, Middlesbrough, Redcar & Cleveland and Stockton-on-Tees.

The non-metropolitan counties of Cheshire and Lancashire; the metropolitan counties of Greater Manchester and Merseyside; and the unitary authorities of Blackburn with Darwen, Blackpool, Halton and Warrington plus the Isle of Man.

The non-metropolitan counties of East Sussex, Kent, Surrey and West Sussex; the unitary authorities of Brighton & Hove, Medway Towns; the London Boroughs of Bexley, Bromley, Croydon, Greenwich, Kingston, Lambeth & Merton, Lewisham, Richmond, Southwark, Sutton and Wandsworth.

The non-metropolitan counties of Cornwall, Devon and Somerset: the unitary authorities of Bath, North Somerset, North-East Somerset, Plymouth and Torbay plus the Isles of Scilly.

The non-metropolitan counties of Dorset, Hampshire and Wiltshire; the unitary authorities of Bournemouth, Poole, Portsmouth, Southampton and Swindon plus the Channel Isles.

The non-metropolitan counties of Staffordshire and Warwickshire; the metropolitan county of West Midlands; the unitary authority of Stoke-on-Trent.

The non-metropolitan county of North Yorkshire; the metropolitan counties of South Yorkshire and West Yorkshire; the unitary authorities of the East Riding of Yorkshire, Kingston-upon-Hull and York.