| Cactus Novelty Limited | Wholesale & retail | 2022 |
| Caden Construction Ltd | Construction | 2019 |
| Cadp Holdings Limited | Real estate | 2025 |
| Cadstreamline Ltd | Information & communication | 2025 |
| Cafe Y PAN Ltd | Hospitality | 2023 |
| Cafecourt Limited | Real estate | 1991 |
| Caffechino Ltd | Administrative & support | 2019 |
| Cafima Limited | Hospitality | 2023 |
| Caisse Epargne Ltd | Transport & logistics | 2026 |
| Cakes & Bakes Franchise Ltd | Wholesale & retail | 2022 |
| Cakes & Bakes Holdings Ltd | Wholesale & retail | 2018 |
| Cakes & Bakes London Ltd | Wholesale & retail | 2019 |
| Cakes & Bakes Ltd | Wholesale & retail | 2019 |
| Cakes by LA Ltd | Manufacturing | 2021 |
| Cakes X Crêpes Group Ltd | Wholesale & retail | 2024 |
| Calco Accounting Ltd | Professional & scientific | 2022 |
| Caledonian Building Services (South East) Limited | Construction | 2003 |
| Caledonian Pharma Ltd | Wholesale & retail | 2019 |
| Calidad Support Services Limited | Construction | 2013 |
| Calm Reach UK CIC | Health & social care | 2026 |
| Calmpal Technologies Ltd | Information & communication | 2026 |
| Calnik Express Ltd | Transport & logistics | 2023 |
| Calo Clean Ltd | Transport & logistics | 2017 |
| Calons Services Limited | Wholesale & retail | 2020 |
| Camayan's Ltd | Health & social care | 2022 |
| Cambelly Ltd | Information & communication | 2026 |
| Camber Group Limited | Real estate | 2004 |
| Camber Limited | Information & communication | 2005 |
| Camber London Limited | Information & communication | 2020 |
| Cambridge Security Services Ltd | Administrative & support | 2010 |
| Cambridge Surfacing Limited | Construction | 2019 |
| Cameron House Care Home Ltd | Health & social care | 2024 |
| Camlar Lighting Solutions Limited | Other services | 2014 |
| CAN Electric & Electronic Services Ltd | Professional & scientific | 2020 |
| Canada Square Funding 2020-1 PLC | Financial services | 2020 |
| Canada Square Funding 2020-2 PLC | Financial services | 2020 |
| Canada Square Funding 2021-2 PLC | Financial services | 2021 |
| Canada Square Funding 7 PLC | Financial services | 2022 |
| Candles Obsession Ltd | Manufacturing | 2024 |
| Candu Internals Ltd | Construction | 2022 |
| Candy and Crumb Limited | Manufacturing | 2026 |
| Canhil Mechanical and Piping Inspection Ltd | Other services | 2024 |
| Cannan Limited | Health & social care | 2014 |
| Cano Training Services Limited | Education | 2002 |
| Canpro Business Solutions Limited | Information & communication | 2016 |
| Canterbury Finance NO.2 PLC | Financial services | 2020 |
| Canterbury Finance NO.3 PLC | Financial services | 2020 |
| Cantor Investments Limited | Financial services | 2020 |
| Cantor Properties 2 Limited | Real estate | 2015 |
| Cantor Properties 3 Limited | Real estate | 2016 |
| Cantor Properties Limited | Real estate | 2014 |
| CANVAS13 Ltd | Arts & recreation | 2025 |
| Capelli Amore Limited | Wholesale & retail | 2018 |
| Capital Electrical Contracts Limited | Construction | 2016 |
| Capital Energy Solutions Limited | Energy | 2026 |
| Capital Investments (South East) Limited | Real estate | 2009 |
| Capital Milestone Consultant Ltd | Education | 2021 |
| Capital New Homes Group Limited | Construction | 2019 |
| Capricorn Centre (Basildon) Limited | Professional & scientific | 1989 |
| Captain's BNK Ltd | Real estate | 2019 |
| Car & Commercial Services (Maidstone) Limited | Wholesale & retail | 2013 |
| Car Doctor & Daniel Ltd | Wholesale & retail | 2020 |
| Car Wrap Express and Design Ltd | Professional & scientific | 2021 |
| Carberry Build (UK) Limited | Other services | 2006 |
| Carbon Crown Ltd | Manufacturing | 2016 |
| Cardboxuk Ltd | Wholesale & retail | 2024 |
| Cardescu Limited | Information & communication | 2025 |
| Cardinal Goods Limited | Wholesale & retail | 2021 |
| Cardusio Ltd | Wholesale & retail | 2019 |
| Care 365 Civil Engineering Limited | Construction | 2022 |
| Care and Wellbeing Group Limited | Health & social care | 2009 |
| Care and Wellbeing Holdings Limited | Financial services | 2024 |
| Care Essence Complex Care Limited | Health & social care | 2024 |
| Care on Call Buddy Limited | Transport & logistics | 2025 |
| Care Serve Limited | Health & social care | 2019 |
| Career Ladder Healthcare Ltd | Administrative & support | 2016 |
| CAREISRAEL76 Ltd | Health & social care | 2023 |
| Caresoft Global Holdings Limited | Professional & scientific | 2016 |
| Caresoft Global Limited | Information & communication | 2007 |
| Caresoft Global Technologies Limited | Information & communication | 2024 |
| Caresoft Holdings Limited | Financial services | 2024 |
| Caresoft Technologies Holdings Limited | Financial services | 2024 |
| Carewetech Limited | Information & communication | 2022 |
| Carexa Limited | Health & social care | 2025 |
| Caris Health Ltd | Health & social care | 2022 |
| Carl Jenkins Plastering Limited | Construction | 2008 |
| Carla Brooks Limited | Other services | 2022 |
| Carlton Armitage Property Limited | Construction | 2021 |
| Carmelo Contracting Limited | Water & waste | 2023 |
| Caro Bodyshop Limited | Wholesale & retail | 2025 |
| Caronne Care Limited | Health & social care | 2013 |
| Carpano Consulting Limited | Professional & scientific | 2023 |
| Carpatian Resources & Solutions Ltd | Professional & scientific | 2022 |
| Carpe Diem (Romford) Limited | Real estate | 2016 |
| Carpenter Arms Ltd | Construction | 2020 |
| Carpenters Couriers Ltd | Transport & logistics | 2022 |
| Carpentry and Gardening Limited | Manufacturing | 2025 |
| Carpet Moods (UK) Limited | Extraterritorial | 1993 |
| Cart Assist Limited | Information & communication | 2015 |
| Cartamundi (UK) Ltd | Manufacturing | 1991 |