| C&D ROD Ltd | Real estate | 2018 |
| C&M Bourne Limited | Real estate | 2017 |
| C. Colomar Art Limited | Administrative & support | 2026 |
| C. Wood & SON (Luton) Limited | Construction | 1990 |
| C.A. Pilgrim 4 Limited | Real estate | 2007 |
| C.C.& R.J.Emerson Limited | Transport & logistics | 1963 |
| C.C.S. Floorings Limited | Construction | 1977 |
| C.H Virtual Service Ltd | Administrative & support | 2023 |
| C.M.F. (Slough) Limited | Other services | 1995 |
| C.R.Engineering Works(Waddesdon)Limited | Manufacturing | 1970 |
| CA Property Holding Ltd | Real estate | 2020 |
| Caazzo Limited | Manufacturing | 2022 |
| Cabal Studio Ltd | Professional & scientific | 2024 |
| Cabana Ltd | Professional & scientific | 2021 |
| Cabtax Limited | Financial services | 2026 |
| Cabubble Limited | Information & communication | 2008 |
| Cactus Business Solutions Ltd | Information & communication | 2011 |
| Cadarn Advisory Limited | Administrative & support | 2026 |
| Cadastra Limited | Financial services | 1987 |
| Caddington Garage Limited | Wholesale & retail | 2003 |
| Cade Holdings Limited | Real estate | 2015 |
| Cadency Ltd | Professional & scientific | 2022 |
| Cadion Marketing Limited | Professional & scientific | 2026 |
| Cadoxton Place Management Company Limited | Households | 2012 |
| CAE Scenery Limited | Construction | 2015 |
| Caelian Consulting Ltd | Professional & scientific | 2015 |
| Caffeine Service Ltd | Professional & scientific | 2015 |
| Caimino Consulting Ltd | Extraterritorial | 2024 |
| Cain Joseph Limited | Construction | 2026 |
| Cairnpark Merlin Properties Limited | Real estate | 2018 |
| Cake Bake Ltd | Hospitality | 2021 |
| Cakewithlove Ltd | Hospitality | 2026 |
| CAL Macbeth Limited | Information & communication | 2020 |
| Calaed Limited | Professional & scientific | 2025 |
| Calder Recruitment Services Ltd | Construction | 2015 |
| CALL4LOCUMS Limited | Administrative & support | 2012 |
| Calla Social Ltd | Professional & scientific | 2020 |
| Callan Residential Properties Limited | Real estate | 2012 |
| Callum Ewen Transport Limited | Transport & logistics | 2017 |
| Calvers Italian Bar and Kitchen Ltd | Hospitality | 2021 |
| Calvers Neighbourhood Bar Ltd | Hospitality | 2015 |
| CAM Metal Consultants Limited | Administrative & support | 2015 |
| Cambridge Risk Limited | Professional & scientific | 2004 |
| Cambridge Square (QT) Limited | Real estate | 2021 |
| Cambs Taverns Limited | Hospitality | 2017 |
| Camen Holdings Limited | Financial services | 2018 |
| Cameron Ventures (Diss) Limited | Hospitality | 2021 |
| Cameron Ventures (Ipswich) Limited | Hospitality | 2016 |
| Cameron Ventures (Priory) Limited | Hospitality | 2015 |
| Cameron Ventures Group Limited | Construction | 1998 |
| Cameron Ventures Hotels Limited | Hospitality | 2017 |
| Camp Collective Ltd | Arts & recreation | 2021 |
| Camp Liberal Club & Public Hall Company Limited(The) | Hospitality | 1906 |
| Camvision International Academy Limited | Education | 2023 |
| Camvision Ltd. | Real estate | 2016 |
| Candatech Limited | Information & communication | 2011 |
| Candidate App Limited | Administrative & support | 2025 |
| Candour Care Services (Broadview) Limited | Health & social care | 2000 |
| Candour Care Services (Homeside) Limited | Health & social care | 2000 |
| Cannell Media Services Limited | Professional & scientific | 2016 |
| Cannon Solutions Limited | Administrative & support | 2025 |
| Cannor Natural Healthcare Ltd | Wholesale & retail | 2024 |
| Cantura Limited | Information & communication | 2005 |
| CAP IV Consulting Ltd | Professional & scientific | 2022 |
| Cape Grape Wine Company Ltd | Wholesale & retail | 2020 |
| Caper Ceilidh Dance School Limited | Arts & recreation | 2017 |
| Capes Gittins Limited | Professional & scientific | 2007 |
| Capital Coherence Limited | Wholesale & retail | 2024 |
| Capital Finance Holdings Ltd | Financial services | 2024 |
| Capital Financial Markets Limited | Financial services | 2012 |
| Capital News Enterprise Ltd | Wholesale & retail | 2019 |
| Capraben Limited | Information & communication | 2021 |
| Capricornio Capital Ltd | Financial services | 2024 |
| Captain Ironman Limited | Real estate | 2021 |
| Capwell Property Hold Co. NO. 4 Limited | Construction | 2007 |
| Car Agent Sourcing Limited | Wholesale & retail | 2025 |
| Car Traders Ltd | Wholesale & retail | 2025 |
| Caramel Homes Limited | Construction | 2021 |
| Carbon Audits Limited | Construction | 2017 |
| Carbon NIL Medical Limited | Wholesale & retail | 2024 |
| Carcani Ltd | Hospitality | 2025 |
| Carella Limited | Professional & scientific | 2018 |
| Careness Limited | Health & social care | 2024 |
| Carerr Limited | Information & communication | 2024 |
| CARERS4UK Ltd | Administrative & support | 2022 |
| Caresca Ltd | Health & social care | 2021 |
| Carevyn Limited | Health & social care | 2024 |
| Carey London Limited | Construction | 2011 |
| Carey Plant Limited | Administrative & support | 2013 |
| Carisbrook Sayers Limited | Administrative & support | 2019 |
| Carl Groves Digital Management Ltd | Professional & scientific | 2024 |
| Carlson Haynes Limited | Education | 2015 |
| Carlton Court (Harpenden) Management Company Limited | Administrative & support | 1989 |
| Carlton Utilities Limited | Construction | 2024 |
| Carmelos Ltd | Hospitality | 2024 |
| Carmona Capital Limited | Professional & scientific | 2021 |
| Carolan Coaching Limited | Other services | 2018 |
| Carousel Recordings Ltd | Information & communication | 2025 |
| Carpets ARE US Ltd | Wholesale & retail | 2025 |
| Carrington QA Ltd | Professional & scientific | 2012 |