| Capathon Estates Ltd | Construction | 2018 |
| CAPEHILL14 Ltd | Real estate | 2021 |
| CAPEHILL8 Ltd | Real estate | 2024 |
| Capital Builders Contractors Ltd | Construction | 2015 |
| Capital Cabling Limited | Information & communication | 2002 |
| Capital Fire and Flood Restoration Ltd | Administrative & support | 2026 |
| Capital Heating Limited | Construction | 1995 |
| Capital Properties (Middlesex) Ltd | Real estate | 2025 |
| Capital QS Limited | Professional & scientific | 2010 |
| Cappa Construct Limited | Construction | 2023 |
| Caprilib Houses Management (Flackwell Heath) Limited | Real estate | 1978 |
| Capstone Surveyors Ltd | Professional & scientific | 2020 |
| Captain Fantastic Franchise Limited | Arts & recreation | 2015 |
| Captain Fantastic Ltd | Administrative & support | 2022 |
| Car Google Ltd | Transport & logistics | 2019 |
| Car Hub Peterborough Ltd | Wholesale & retail | 2018 |
| Car Lelo Limited | Wholesale & retail | 2025 |
| Car Sense Ltd | Wholesale & retail | 2024 |
| Car Vend Ltd | Wholesale & retail | 2022 |
| Car Wellness Centre Ltd | Wholesale & retail | 2024 |
| Car-Holics Ltd | Wholesale & retail | 2023 |
| Car-Zone-Uk Limited | Wholesale & retail | 2022 |
| Carbon Consultancy Services Group Ltd | Professional & scientific | 2026 |
| Care Incorporated Ltd | Administrative & support | 2021 |
| Care Talent Advisors Limited | Professional & scientific | 2020 |
| Career Switch Services Limited | Education | 2016 |
| Caremax Solutions Ltd | Health & social care | 2012 |
| Caretech Charitable Foundation | Health & social care | 2018 |
| Caretech Cloud Limited | Information & communication | 2020 |
| Caretech Community Services (NO.2) Limited | Health & social care | 1999 |
| Caretech Community Services Limited | Health & social care | 1993 |
| Caretech Consulting Limited | Real estate | 2010 |
| Caretech Design and Build Limited | Construction | 2021 |
| Caretech Digital Limited | Information & communication | 2021 |
| Caretech Estates (NO 2) Limited | Real estate | 2008 |
| Caretech Estates (NO 3) Limited | Real estate | 2008 |
| Caretech Estates (NO 6) Limited | Administrative & support | 2013 |
| Caretech Estates (NO 7) Limited | Real estate | 2013 |
| Caretech Estates (NO. 5) Limited | Real estate | 2009 |
| Caretech Estates (NO.4) Limited | Real estate | 2008 |
| Caretech Estates (NO8) Limited | Real estate | 2025 |
| Caretech Estates Limited | Real estate | 2006 |
| Caretech Foster Care Limited | Health & social care | 2004 |
| Caretech Fostering Holdings Limited | Health & social care | 2010 |
| Caretech Fostering Services Limited | Health & social care | 2010 |
| Caretech Holdings Limited | Professional & scientific | 2002 |
| Caretech Housing Services Limited | Health & social care | 1997 |
| Caretech International Limited | Health & social care | 2009 |
| Carfinanced Limited | Wholesale & retail | 2021 |
| Carmen Diagnostic Technologies Limited | Professional & scientific | 2021 |
| Carno Bedroom Kitchen Ltd | Manufacturing | 2023 |
| Caro Building Services Ltd | Construction | 2016 |
| Carrington and Dewhurst Limited | Extraterritorial | 1930 |
| Carsflex Limited | Wholesale & retail | 2024 |
| Cart Consulting Limited | Information & communication | 2013 |
| Cart Solutions Limited | Wholesale & retail | 2026 |
| Cartel Property Ltd | Real estate | 2024 |
| Cartel Services Limited | Information & communication | 1997 |
| Carter's END Ltd | Manufacturing | 2024 |
| Cartwise Ltd | Wholesale & retail | 2025 |
| Carz Culture Ltd | Wholesale & retail | 2025 |
| Casa One Limited | Real estate | 2017 |
| Casaribo Properties Ltd | Real estate | 2026 |
| Cascade Cards Ltd | Wholesale & retail | 2025 |
| Casey Coaches Ltd | Health & social care | 2024 |
| Casmagsy Limited | Health & social care | 2014 |
| Castia Marble Limited | Construction | 2017 |
| Castileon Apartments Residents Association Limited | Real estate | 2003 |
| Castillo Blanco Ltd | Financial services | 2019 |
| Castle View Gardens Management Company Limited | Households | 1987 |
| Castleline Developments Limited | Administrative & support | 2014 |
| Castleline Distribution Limited | Wholesale & retail | 2018 |
| Castleline Limited | Real estate | 2003 |
| Cat Steel Services Ltd | Construction | 2023 |
| Catalin Teaca Limited | Administrative & support | 2017 |
| Catalunya Golf Limited | Other services | 1993 |
| Catalyst Equity Partners Limited Liability Partnership | | 2002 |
| Catch U Drainage Solutions Ltd | Water & waste | 2024 |
| Catdogsupplies Ltd | Wholesale & retail | 2025 |
| Catec Energy Ltd | Administrative & support | 2022 |
| Catering Equipment Solutions Ltd | Hospitality | 2016 |
| Catering Hygiene Specialists Limited | Wholesale & retail | 1998 |
| Catharsis Group Ltd | Health & social care | 2017 |
| Catlanta Ltd | Information & communication | 2021 |
| Caulfield Properties Limited | Real estate | 2019 |
| Cavaleiro Ltd | Administrative & support | 2025 |
| CB Hounslow Sports & Social Club Limited | Arts & recreation | 2011 |
| Cbbxpert Care Ltd | Health & social care | 2021 |
| Cbhcoaching Limited | Other services | 2024 |
| CBT Canary Wharf Ltd | Other services | 2012 |
| CBW Corp Limited | Wholesale & retail | 2025 |
| CC Construction Building Limited | Construction | 2019 |
| CC Loft Conversion Ltd | Construction | 2020 |
| Ccep Finance (Australia) Limited | Financial services | 2021 |
| Ccep Group Services Limited | Professional & scientific | 2013 |
| Ccep Holdings (APS) Limited | Financial services | 2020 |
| Ccep Holdings UK Limited | Financial services | 2016 |
| Ccep Ventures Europe Limited | Financial services | 2018 |
| Ccep Ventures UK Limited | Financial services | 2018 |
| CCM Leisure Holdings Limited | Financial services | 2025 |