THEMiS

Local authorities:

Cornwall County Council
Bedfordshire County Council
Bracknell Forest Council
Essex County Council
London Borough of Haringey
West Lothian Council
Belfast City Council
Chester City Council
Durham Police
Greater Manchester Police
Thames Valley Police
Wiltshire Police

Universities:

Southern Universities Purchasing Consortium
London Universities Purchasing Consortium
University of London
Nottingham Trent University
University of Wales - Swansea
University of Strathclyde
University of Northumbria at Newcastle
University of Wales College of Medicine
University of Bristol

NHS:

Gloucestershire Royal NHS Trust
Oxford Radcliffe Hospital NHS Trust
Chesterfield Royal Hospital NHS Trust
ISSG Common Service Agency
National Health Service Scotland
Purchasing & Supply Agency (PASA)
Mid Cheshire NHS Trust
Heatherwood & Wexham Park NHS Trust

Utility/Oil and Gas:

Mid Kent Water
Scottish & Southern Energy Plc
Marathon Oil UK limited
Northern Electric Distribution Ltd
British Gas Services Limited
ExxonMobil North Sea Limited
London Underground
National Grid Company plc
Bristol Water
Innogy

Solicitors:

Freshfields Bruckhaus Deringer
Allen & Overy
Linklaters
Bird & Bird
Lovells
Bevan Britton
Simmons & Simmons

Housing Associations:
Bromford Housing Group
NI Housing Executive
Glasgow Housing Association
Places for people
CITB Construction Skills
English Churches Housing Group

Other:

Research Councils (RCPO)
English Heritage
Department of Environment, Transport & Regions
Transport for London
Office of Government Commerce
Merseyside Fire Brigade
The Environment Agency 
Natural History Museum
RC UK - SSC Ltd