| Concepto CN Limited | Purley | 2023 |
| Concepts College London Limited | London | 2017 |
| Conceptual Engineering Inc Ltd | Tunbridge Wells | 2022 |
| Concern SRI Lanka Foundation Limited | Middlesex | 2007 |
| Concerned Medics Foundation Ltd | Barnstaple | 2025 |
| Concert Canary Ltd. | London | 2017 |
| Concerteenies | Sheffield | 2022 |
| Concertino Limited | Brentwood | 2018 |
| Conchieve Ltd | London | 2021 |
| Concise Clinical Consulting Limited | London | 2006 |
| Concise Professional Development Limited | St. Helens | 2017 |
| Concord College International Limited | Shrewsbury | 2017 |
| Concord School of Business Excellence (Csbe) Ltd | London | 2024 |
| Concord Video and Film Council Limited | Rosehill Centre, Ipswich | 1964 |
| Concorde (International) Summer Schools Limited | Canterbury | 1972 |
| Concorde International Education Group Limited | Canterbury | 2021 |
| Concorde International Limited | Canterbury | 2021 |
| Concordia Multi Academy Trust | Ellesmere Port | 2016 |
| Concordia Music Ltd | Nottingham | 2014 |
| Concordia Worldwide Education Limited | London | 2019 |
| Concrete Canvas Boxing Gym CIC | Sheffield | 2025 |
| Concrete Communities CIC | London | 2025 |
| Concrete Kids Academy C.I.C. | London | 2026 |
| Concrete Rose Collective CIC | St. Ives | 2020 |
| Concreted College Limited | London | 2024 |
| Concrew Training Limited | Mansfield | 2014 |
| Concuss-Ed Ltd | Bo'Ness | 2021 |
| Condeconsult Limited | London | 2017 |
| Condition Collective Ltd | Hornchurch | 2024 |
| Conditioned by Claire Fitness Ltd | Banff | 2023 |
| Conditions Limited | Croydon | 2018 |
| Conditions Online Limited | Croydon | 2024 |
| Conduct Education Behaviour Change Services Ltd | Wolverhampton | 2026 |
| Conductive Education (Bristol) Community Interest Company | Portishead | 2014 |
| Conductology C.I.C. | Londonderry | 2019 |
| Condutto CIC | London | 2024 |
| Conexus Conflict Consultancy Limited | London | 2017 |
| Confederation of Public Financial Accountants Limited | London | 2021 |
| Confederation of School Trusts | London | 2004 |
| Confederation of Tourism & Hospitality Limited | Rugeley | 1987 |
| Confer Education Ltd | Plymouth | 2023 |
| Conferences South West Limited | Crediton | 2011 |
| Conferenzia World Limited | London | 2019 |
| Confetti Media Limited | Nottingham | 2015 |
| Confidance Academy Ltd | Manchester | 2025 |
| Confidence Academy Ltd | Salford | 2020 |
| Confidence Academy of Swimming Limited | Wimborne | 2015 |
| Confidence Circuit Limited | Halifax | 2026 |
| Confidence Driving School Limited | Sevenoaks | 2024 |
| Confidence in Clinic Ltd | Maldon | 2025 |
| Confidence Makers CIC | Paignton | 2023 |
| Confidence Through Sport Ltd | Bucks | 2019 |
| Confidence With SJ Ltd | Huddersfield | 2025 |
| CONFIDENCE2CARE Training & Event Medics Ltd | Melton Mowbray | 2024 |
| Confident & Connected Ltd | Bicester | 2020 |
| Confident Communication Limited | London | 1998 |
| Confident Communities | Leicester | 2014 |
| Confident Cyclists Ltd | Crawley | 2021 |
| Confident Friendly Driving Limited | Barnet | 2014 |
| Confident Kids Ltd | Bracknell | 2026 |
| Confident Learners Ltd | Peterborough | 2022 |
| Confident Learning Limited | Stroud | 2009 |
| Confident Mind Limited | Bournemouth | 2024 |
| Confident Minds Academy Limited | Folkestone | 2026 |
| Confident YOU Training Ltd | London | 2024 |
| Confined Spaces Training Services Limited | Hull | 1988 |
| Confirma Education Limited | Stoke-On-Trent | 2018 |
| Conflict and Governance Training Ltd | Canterbury | 2025 |
| Conflict Resolution Education in Sheffield Schools Training | Sheffield | 2006 |
| Conflict Resolution Skills Training Limited | Tunbridge Wells | 2017 |
| Conflict Resolutions Training & Consultancy Limited | Cardiff | 2017 |
| Conflict&Resolution.Uk Ltd | Liverpool | 2026 |
| Conflicts Education (Messengers Education) C.I.C. | Hounslow | 2022 |
| Confluence (UK) Limited | Hitchin | 2014 |
| Confucius International School Chengdu UK Branch Limited | Diss | 2016 |
| Cong. D'Satmar Limited | Salford | 2011 |
| Congleton Primary Academy Trust Limited | Congleton | 2014 |
| Congleton Rugby Union Football Club Ltd | Congleton | 2013 |
| Congolese Community of Birmingham CIC | Birmingham | 2026 |
| Congolese Diaspora Next Generation Community Interest Company | Salford | 2025 |
| Congrapps Limited | London | 2019 |
| Congregation Sharei Sholom Tchabe Limited | Woodford Green | 2006 |
| Congregational Memorial Hall Trust (1978) Limited(The) | Northampton | 1978 |
| Conice UK Ltd | London | 2013 |
| Conisbrough Ivanhoe Primary Academy | Doncaster | 2011 |
| Conker Club Limited | Camberley | 2017 |
| Conker Finance Ltd | London | 2021 |
| Conker Mental Health Ltd | Daventry | 2023 |
| Conkers 4 Kids Ltd | Norfolk | 2003 |
| Conkers Group Ltd | Diss | 2022 |
| Conkers Life Ltd | Hindley | 2018 |
| Conlan School Limited | Norwich | 2008 |
| Connaught House School Limited | | 1958 |
| Connaught School for Girls | London | 2013 |
| Connaughton Consultancy Ltd | Manchester | 2022 |
| Connect 2 the Future Ltd | Kenilworth | 2023 |
| Connect 4 Change CIC | Romford | 2023 |
| Connect Academy Limited | Liverpool | 2019 |
| Connect Academy Trust | Plymouth | 2016 |
| Connect Alliance Trust | Manchester | 2013 |