| Nom | UIT-R | UIT-T | UIT-D | Catégories |
| Department for Science, Innovation and Technology, LONDON | | | | MINISTRY |
| Office of Communications - Ofcom, LONDON | | | | ADMIN / REGULATOR |
| Gibraltar Regulatory Authority, GIBRALTAR | | | | ADMIN RELATED |
| International Communications, Business Relations 2, LONDON | | | | ADMIN RELATED |
| 3G Telecommunications Limited, LEEDS | | ASSOCIATE SG2 | | SIO / SERVICE PROVIDER |
| AALTO HAPS Limited, Farnborough | X | | | OTHER ENTITY |
| ABS, HAMILTON | X | | | OTHER ENTITY |
| Access Partnership Limited, LONDON | X | | X | SIO |
| Access Space Alliance Ltd, London | ASSOCIATE SG4 | | | OTHER ENTITY |
| Airbus Defence and Space Ltd, CORSHAM | X | | | ROA |
| ApplianSys, Coventry | | | X | OTHER ENTITY |
| aql (numbering) Ltd., Leeds | | ASSOCIATE SG2 | | ROA |
| ARM Limited, CAMBRIDGE | | ASSOCIATE SG2 | X | ROA / SERVICE PROVIDER |
| Astroscale Ltd., Didcot, Oxford | X | | | ROA / SERVICE PROVIDER |
| Avanti Hylas 2 Limited, LONDON | X | | X | ROA / OPERATOR |
| Aviat Networks, BLANTYRE, GLASGOW | | ASSOCIATE SG15 | | ROA |
| Bourns Limited, BEDFORD | | ASSOCIATE SG5 | | SIO |
| British Broadcasting Corporation (BBC), LONDON | X | | | ROA |
| British Telecommunications Plc. (BT Plc), LONDON | X | X | | ROA |
| Broadcom Europe Ltd., Reading | | X | | SIO |
| Cable & Wireless Communications Plc, LONDON | | X | | ROA |
| Calnex Solutions plc., LINLITHGOW | | ASSOCIATE SG15 | | SIO / SERVICE PROVIDER |
| Capital City Service Limited, Watford | | ASSOCIATE SG17 | | ROA |
| CentralNic Group PLC, London | | | ASSOCIATE SG2 | SIO |
| Chronos Technology Limited, LYDBROOK | | ASSOCIATE SG15 | | SIO |
| Dense Air, Marlow | | ASSOCIATE SG2 | | ROA |
| DNS Research Federation, OXFORD | | ASSOCIATE SG13 | | OTHER ENTITY |
| Encompass Digital Media Services Limited, London | X | | | ROA |
| Eseye Ltd., Guildford | | ASSOCIATE SG2 | | SIO |
| ESim Go Limited, Banbury | | ASSOCIATE SG2 | | ROA / OPERATOR |
| Eutelsat OneWeb, LONDON | | X | | ROA / SERVICE PROVIDER |
| Flo Live Limited, Uckfield | | ASSOCIATE SG2 | | SIO |
| GibFibre Ltd., Gibraltar | | ASSOCIATE SG2 | | SIO / SERVICE PROVIDER |
| iONLINE Internet solutions provider Ltd., Kingsnorth Ashford | | ASSOCIATE SG2 | | SIO / SERVICE PROVIDER |
| JT (Jersey) Limited, ST. HELIER, JERSEY | | ASSOCIATE SG2 | | ROA |
| Littelfuse UK Ltd., SWINDON | | ASSOCIATE SG5 | | SIO |
| Manx Telecom Trading Ltd., BRADDAN, Isle of Man | | ASSOCIATE SG2 | | ROA / SERVICE PROVIDER |
| MediaLincc Limited, DOUGLAS, ISLE OF MAN | | ASSOCIATE SG2 | | SIO |
| Monty UK Global Ltd, London | | ASSOCIATE SG2 | | SIO |
| Netscout, IPSWICH | | X | | SIO |
| NTT Ltd. Group Services Limited, London | | ASSOCIATE SG2 | | SIO / SERVICE PROVIDER |
| Omnispace UK Limited, HIGH WYCOMBE | X | | | SIO |
| OpenSignal Limited, London | | ASSOCIATE SG12 | | ROA |
| Podsystem Ltd., Buckingham | | ASSOCIATE SG2 | | ROA / SERVICE PROVIDER |
| River Advisers, Parkfield, Douglas | ASSOCIATE SG4 | | | SIO |
| RTFM LLP, GLASGOW | | X | | OTHER ENTITY |
| Sama Telecom Ltd, LONDON | | ASSOCIATE SG2 | | ROA |
| Sawatch Limited, MILTON KEYNES | | ASSOCIATE SG2 | | ROA |
| Senko Advanced Components (Euro) Ltd., Daneshill, Basingstoke | | ASSOCIATE SG15 | | SIO |
| Simwood Group Plc, Bristol | | ASSOCIATE SG2 | | ROA / OPERATOR |
| Six Degrees Labs Ltd, Farnham | | | X | SIO / SERVICE PROVIDER |
| Sky Group, ISLEWORTH | | ASSOCIATE SG9 | | ROA |
| Stacuity Limited, Ballasalla, Isle of Man | | ASSOCIATE SG2 | | SIO / SERVICE PROVIDER |
| Tata Communications UK Limited, London | | X | | ROA |
| Tyntec Group Ltd, London | | ASSOCIATE SG2 | | ROA |
| Vodafone Group Services Ltd, NEWBURY | X | X | X | ROA |
| World Mobile Group Ltd., London | | ASSOCIATE SG2 | X | ROA |
