| Clinical Coaching Care Limited | Bury St. Edmunds | 2025 |
| Clinical Consulting VE Limited | Darlington | 2020 |
| Clinical Gold Limited | Bristol | 2024 |
| Clinical Healthcare Limited | London | 2020 |
| Clinical Services Group Ltd | Alfreton | 2024 |
| Clinical Soul Care Limited | Dagenham | 2026 |
| Clinical Training Limited | Northampton | 2011 |
| Clinical Training Solutions Ltd | Tadley | 2018 |
| CLK Fire & Safety Compliance Limited | Carterton | 2016 |
| CLKSL123 Ltd | Poole | 2021 |
| CLM Corporations Ltd | London | 2024 |
| Clmilne Ltd | Bradford | 2025 |
| Clocktower Training Academy Limited | Holywell | 2023 |
| Cloudbreak Group Limited | Poole | 2025 |
| Clover Care Group Limited | Chester | 2024 |
| Cloverleaf Care Limited | Orpington | 2026 |
| CM Fire Protection Ltd | Cookstown | 2018 |
| CM Fire Services NI Ltd | Cookstown | 2021 |
| CM Safety Consultants Ltd | Knottingley | 2024 |
| CMA Consutants Ltd | London | 2025 |
| CMA Fire Assistance Ltd | Wallington | 2024 |
| Cmckenzie Consulting Ltd | Littleborough | 2012 |
| CMD Project Management Limited | Nottingham | 2007 |
| Cmhhealth Ltd | London | 2022 |
| Cmlp Ltd | London | 2024 |
| Cmonitoring Ltd | London | 2020 |
| CMR Fire Prevention Limited | Arundel | 2017 |
| Cmsg 008 Ltd | Cardiff | 2020 |
| Cmsg 017 Ltd | Cardiff | 2020 |
| CMV Healthcare Ltd | Coventry | 2023 |
| CMW Healthcare Ltd | Bristol | 2026 |
| CNF London Ltd | Leigh-On-Sea | 2023 |
| CNW Fire Solutions Ltd | Chester | 2023 |
| Coaching for Productivity and Growth Limited | Brighton | 2024 |
| Coachsafe Ltd | Ely | 2015 |
| Coarha Limited | Ayr | 2014 |
| Coastal Fire Safety Ltd | Cardigan | 2026 |
| Coastal Fire Systems Limited | Littlehampton | 2023 |
| Coastline Fire Alarms Limited | Lewes | 2019 |
| Coastline Fire Protection Limited | Lewes | 2008 |
| Cobra Public Relations Limited | Shaftesbury | 2012 |
| Coco Aesthetics Clinic Limited | Bo'Ness | 2024 |
| Codi Fire Ltd | Wickford | 2020 |
| Codie's Counselling Ltd | Doncaster | 2025 |
| Coeliacs in Safe Hands CIC | Newport | 2025 |
| COG Safety Solutions Limited | Londonderry | 2024 |
| Cogent Skills Training Limited | Warrington | 2007 |
| Cogent SSC Limited | Edinburgh | 1991 |
| Cognisant Health CIC | Newcastle Upon Tyne | 2021 |
| Cognitivecare Ltd | Colchester | 2025 |
| Cogunn Limited | Dundee | 2014 |
| COL B Ltd | Colchester | 2013 |
| Colcarl Ltd | Milton Keynes | 2023 |
| Cold CUT Systems Limited | Southampton | 2019 |
| Cole Medical Limited | Stafford | 2023 |
| Coleford Youth and Community Hub CIC | Radstock | 2014 |
| Colehayes Consulting Ltd | Thame | 2019 |
| Coles Fire Systems Limited | Taunton | 2016 |
| Colin King Fire Consultancy Ltd | Ashford | 2025 |
| Collective for Climate Action CIC | Ludlow | 2025 |
| Collective Home Care Scotland Ltd | Aberdeen | 2024 |
| College of Integrative Medicine Ltd | Milton Keynes | 2025 |
| College of Management Technology Limited | Romford | 2025 |
| College of Operating Department Practitioners | London | 2006 |
| Collier Care Plus Ltd | London | 2026 |
| Collum Safety Services Limited | Glasgow | 2024 |
| Colmore Business District Limited | Birmingham | 2008 |
| Colver Services Ltd | Camberley | 2022 |
| Combat Fire Solutions Ltd | Colchester | 2024 |
| Comfort Cove Care Limited | Birmingham | 2024 |
| Comfort Healthcare Ltd | Corby | 2020 |
| Comfort M Ltd | London | 2024 |
| Comfort Residence Ltd | Bedford | 2023 |
| Comforting Care Solutions Limited | London | 2024 |
| Commercial Fire Limited | Northampton | 2025 |
| Commercial Fire Systems Ltd | Rossendale | 2021 |
| COMMITTED2CARE Ltd | Tamworth | 2017 |
| Common Youth Ltd | Belfast | 1993 |
| Commonwealth Association for Election Administrators | Reading | 2025 |
| Communication North West Ltd | Morecambe | 2022 |
| Communities Connected C.I.C. | Leicester | 2015 |
| Communities Engage and Thrive C.I.C. | Birmingham | 2019 |
| Communities to Bridge CIC | Leeds | 2026 |
| Community Action Group Ltd | Sale | 2025 |
| Community Action Norfolk | Dereham | 1996 |
| Community Advice Support C.I.C. | Accrington | 2025 |
| Community Advice Works Limited | London | 1997 |
| Community Care Angus Montrose Ltd | Montrose | 2025 |
| Community Education and Cultural Association Ltd | London | 2024 |
| Community Gate Support Limited | Leicester | 2022 |
| Community Health Partnerships Limited | Manchester | 2001 |
| Community Healthcare Partnerships Limited | Basildon | 2021 |
| Community Outreach Centre C.I.C. | Birmingham | 2023 |
| Community Resilience UK CIC | Maidstone | 2006 |
| Community Safety (Great Yarmouth) Limited | Great Yarmouth | 2000 |
| Community Welfare Ltd | Welwyn Garden City | 2022 |
| Community Youth Ventures C.I.C. | Amersham | 2018 |
| Como Health Care Ltd | Crewe | 2020 |
| Companion Social Care Ltd | Christchurch | 2025 |
| Compartment Fire Limited | Derby | 2005 |