| Choices Healthcare Services Limited | Corby | 2025 |
| Chosen Fire Protection Ltd | Gloucester | 2017 |
| Chra Locuming Ltd | Greenford | 2023 |
| Chris Anglesea TM Ltd | Doncaster | 2025 |
| Chris Charles Counselling Ltd | Enfield | 2020 |
| Chris Inch Ltd | Brentwood | 2023 |
| Chris Morley Utilities Ltd | Leicester | 2025 |
| Christ Kingdom Ministries CIC | Mildenhall | 2022 |
| Christian Community Trust for Norwich and Norfolk Limited | Norwich | 2004 |
| Christie RAE Physiotherapy Limited | Poole | 2025 |
| Chronically Marvellous Community Interest Company | Hampton | 2023 |
| Chubb Fire Limited | Blackburn | 1914 |
| Chuffed Campaigns CIC | Reigate | 2025 |
| Church Road Businesses Ltd | London | 2022 |
| Churchill Health and Social Care Ltd | Luton | 2019 |
| Chyrich Limited | Sunderland | 2022 |
| Ciana Care Service Ltd | Leicester | 2021 |
| Cicservices Ltd | London | 2014 |
| Cinclus Limited | Bicester | 2012 |
| Cinda Fire Protection Limited | Gloucester | 2023 |
| Cinder Solutions Ltd | Dartford | 2024 |
| Cinnamon Healthcare Services Limited | Luton | 2022 |
| Cipros Ltd | Newark | 2014 |
| Circle of Inspirational Calm C.I.C. | Bolton | 2023 |
| Circlefire Electrical Ltd. | Peterborough | 2009 |
| Cirk Healthcare Ltd | Derby | 2019 |
| Citadel Air Defense Group Ltd | Nottingham | 2026 |
| Citadel Security Group Ltd | London | 2025 |
| Citizens Advice Bureau Tendring | Clacton-On-Sea | 2001 |
| City Centre Initiative Limited | Derry Londonderry | 1997 |
| City Family Church Limited | Coventry | 2020 |
| City Fire Training Ltd | Colchester | 2009 |
| City Marshall Security Ltd | Bristol | 2023 |
| City of Westminster London Private Educationals Limited | London | 2021 |
| City Safety Solutions Limited | London | 2014 |
| City to Sea Property Services Ltd | Ivybridge | 2026 |
| Citygen Solutions Ltd | London | 2022 |
| Citytech Ltd | West Drayton | 2019 |
| Civic Healthcare Limited | Cambridge | 2021 |
| Civil Defence Supply Limited | Lincoln | 1998 |
| CJ Associates Training Limited | Buckinghamshire | 2003 |
| CJ House Ltd | Slough | 2017 |
| CJ Noah Ltd | Ely | 2022 |
| CJA Healthcare Limited | Sittingbourne | 2018 |
| CJC Fire Compliance Ltd | Nottingham | 2025 |
| CJF Advisory Limited | Camberley | 2025 |
| Cjmn 24/7 Ltd | Nottingham | 2020 |
| CJP Fire Protection Ltd | Nottingham | 2019 |
| CJS Governance Limited | Oakham | 2026 |
| CJW Consultancy Limited | Thame | 2023 |
| CK Care Group Ltd | Poulton-Le-Fylde | 2026 |
| Ckalan Ltd | London | 2022 |
| CKD Trading Limited | London | 2020 |
| CKT UK Solutions Ltd | Bolton | 2024 |
| Clackmannanshire Transformation Space CIC | Alloa | 2025 |
| Claims Fast Limited | Manchester | 2018 |
| Clancy Care Home Ltd | Preston | 2019 |
| Clare Home Care Ltd | Grays | 2025 |
| Clarico Healthcare Limited | Nottingham | 2025 |
| Clarissa’S Home Healthcare Services Ltd | Bicester | 2022 |
| Clarity EAR Health Ltd | Southam | 2025 |
| Clarity ND Limited | Stockport | 2025 |
| Clarity Within Cognitive Behavioural Therapy Limited | Romford | 2025 |
| CLARITY-K2 Ltd | Croydon | 2026 |
| Claritymed Anaesthesia Ltd | Wakefield | 2024 |
| Clark Fire Sprinklers Ltd | Glasgow | 2023 |
| Clark Safety Limited | Alness | 2024 |
| Clarke House Care Ltd | Nottingham | 2018 |
| Clarkesconsultancy Limited | Rickmansworth | 2012 |
| Claros Holdings Limited | Manchester | 2026 |
| Claros Operations Limited | Manchester | 2026 |
| Clarosacarehomes Limited | Eccles | 2025 |
| Class Fire Safety Limited | Penryn | 2022 |
| Classic Fire & Security Limited | Southampton | 2006 |
| Classic Fire Limited | St Austell | 2003 |
| Classic Healthcare Ltd | Pontefract | 2023 |
| Classy Care Services Ltd | Southampton | 2026 |
| Claxton Care Ltd | Telford | 2024 |
| CLB & Associates Ltd | Exeter | 2023 |
| Clcm Offshore Services Ltd | Great Yarmouth | 2023 |
| Clean EAR Solutions Ltd | Burntwood | 2025 |
| Clear Safety Services Ltd | Whitstable | 2016 |
| Clear Vision & EYE Care Ltd | Manchester | 2021 |
| Clearcare Healthcare Ltd | High Wycombe | 2020 |
| Clearercare Podiatry Birmingham Limited | Birmingham | 2022 |
| Clearpaths Healthcare Ltd | Leigh-On-Sea | 2024 |
| Clearview Fire and Security Ltd | Beverley | 2022 |
| Cleo Healthcare Limited | Worksop | 2021 |
| Clerkwise Ltd | London | 2023 |
| Cleveland & Kent Ltd | Bridgwater | 2025 |
| Cleveland Fire Safety Limited | Billingham | 2021 |
| Click Fire & Security Limited | Rochdale | 2010 |
| Click Fire Safety Services Ltd | Lisburn | 2024 |
| Client Bridge Child Resi Solutions Ltd | Warrington | 2017 |
| Client Bridge Domicilliary Solutions Ltd | Warrington | 2017 |
| Client-Centred Healthcare Group Ltd | Manchester | 2023 |
| Clift Care Ltd | Banstead | 2026 |
| Clifton 2025 Limited | London | 2011 |
| Climate and Health Awareness Ireland Ltd | Preston | 2024 |
| Clinat Healthcare Service Limited | Leeds | 2024 |