| Callaghan Finch Limited | Real estate | 2012 |
| Callaway Care and Support Limited | Health & social care | 2019 |
| Cambridge Sustainable Landscaping Ltd | Administrative & support | 2020 |
| Cambridge Emergency Medicine LLP | | 2026 |
| Cambridge Property Group Ltd | Real estate | 2020 |
| Camden Barbers Ltd | Other services | 2017 |
| Camden Community Transport Ltd | Transport & logistics | 2013 |
| Cami Group Ltd | Wholesale & retail | 2025 |
| Camlet Warren Limited | Real estate | 2007 |
| Camomile Flowers Limited | Wholesale & retail | 2024 |
| Campden IT Services Ltd | Information & communication | 2020 |
| Canalside London Limited | Construction | 2018 |
| Canary Riverside Car Park Ltd | Other services | 2021 |
| Canarywood Properties Ltd | Real estate | 2022 |
| Candle Crafting Ltd | Wholesale & retail | 2025 |
| Cando Training Limited | Education | 2019 |
| Candor Group Limited | Professional & scientific | 2018 |
| Candor Properties (Harpenden) Limited | Real estate | 2021 |
| Candy Floss Wonderland Limited | Wholesale & retail | 2023 |
| Cane Garden Limited | Information & communication | 2009 |
| Canin Property Ltd | Construction | 2019 |
| Cape Arola Limited | Transport & logistics | 2022 |
| Cape Bernina Limited | Transport & logistics | 2023 |
| Cape Rigi Limited | Transport & logistics | 2024 |
| Cape Sandra Limited | Administrative & support | 2014 |
| Cape Sarina Limited | Administrative & support | 2021 |
| Capella Prime Ltd | Hospitality | 2025 |
| Capesize Holdco Limited | Transport & logistics | 2021 |
| Capita Accountants Ltd | Professional & scientific | 2018 |
| Capital Air Systems Ltd | Manufacturing | 2026 |
| Capital Autobody Limited | Wholesale & retail | 1999 |
| Capital Bedrooms Ltd | Construction | 2018 |
| Capital Car Care Centre Ltd | Wholesale & retail | 2021 |
| Capital Car Glass Ltd | Wholesale & retail | 2013 |
| Capital Certs Ltd | Professional & scientific | 2026 |
| Capital Chauffeur Cars Ltd. | Administrative & support | 2003 |
| Capital Import & Export Co. Ltd | Wholesale & retail | 2018 |
| Capital Partners Limited | Real estate | 2009 |
| Capital Partners London Limited | Financial services | 1999 |
| Capital Plumbing and Heating Ltd | Construction | 2023 |
| Capital Quest Limited | Real estate | 2016 |
| Capital Windows & Repairs Limited | Construction | 2007 |
| Capitaltradinggroup Ltd | Information & communication | 2020 |
| Capp Cart Limited | Wholesale & retail | 2025 |
| Capria Investments Limited | Real estate | 2023 |
| Car Care Service 1 Limited | Wholesale & retail | 2024 |
| Car Clinic (Wembley) Ltd | Wholesale & retail | 2016 |
| Car Spa Limited | Wholesale & retail | 2018 |
| Caratbond UK Ltd | Wholesale & retail | 2025 |
| Caravelis Holdings Ltd | Financial services | 2024 |
| Carderi Ltd | Wholesale & retail | 2018 |
| Cardiff ENT Ltd | Health & social care | 2024 |
| Cardiff Retail Ltd | Wholesale & retail | 2025 |
| Cardoso Tax Services & Administration Limited | Professional & scientific | 2020 |
| Cardoza Technologies Ltd | Wholesale & retail | 2018 |
| Care by Mail Limited | Wholesale & retail | 2012 |
| Care Rite Health Care Ltd | Health & social care | 2022 |
| Careassure Ltd | Health & social care | 2019 |
| Carepage Limited | Administrative & support | 2016 |
| Carewatch Limited | Health & social care | 2023 |
| Carewell Care Ltd | Health & social care | 2026 |
| Cargo Europe Ltd | Transport & logistics | 2019 |
| Cargo Force Limited | Transport & logistics | 2011 |
| Caribbean Music Association | Other services | 2012 |
| Caring Hearts Companions Ltd | Real estate | 2026 |
| Carioquinhafood Limited | Hospitality | 2026 |
| Caris Cove Jamaica Produce Ltd | Wholesale & retail | 2025 |
| Carlton Berkeley Limited | Professional & scientific | 2014 |
| Carlton One Investments Limited | Real estate | 2022 |
| Carmen's Coaching Ltd | Other services | 2025 |
| Carpathia Projects Limited | Construction | 2026 |
| Carrot London Ltd | Professional & scientific | 2012 |
| Cars A&E Ltd | Wholesale & retail | 2017 |
| Carvenience Ltd | Wholesale & retail | 2025 |
| Carz Khan Ltd | Wholesale & retail | 2019 |
| Casa DI Pasta Ltd | Hospitality | 2025 |
| Casa MAX Ltd | Real estate | 2025 |
| Casa PN Ltd | Real estate | 2025 |
| Casa Removals Ltd | Transport & logistics | 2026 |
| Case Gods Ltd | Wholesale & retail | 2017 |
| Cashbench Ltd | Professional & scientific | 2017 |
| Cashvalent Ltd | Wholesale & retail | 2021 |
| Castell Online Media Ltd | Information & communication | 2016 |
| Castle Education Limited | Education | 2014 |
| Castle END Designs Ltd | Professional & scientific | 2018 |
| Castle Market Ltd | Wholesale & retail | 2022 |
| Castle News Limited | Wholesale & retail | 2003 |
| Castleton for Agricultural Technology & Development Ltd | Agriculture & fishing | 2020 |
| Cata Building & Landscaping Ltd | Construction | 2023 |
| Catalin Petrisor Ltd | Construction | 2016 |
| Catalyst Business Consultancy Ltd | Wholesale & retail | 2026 |
| Catbird Ltd | Manufacturing | 2011 |
| Catchbow Engineering Limited | Professional & scientific | 2013 |
| Catchet London Ltd | Real estate | 2020 |
| Catel Contracts International Ltd | Education | 1993 |
| Catford Ltd | Hospitality | 2025 |
| Catwalk Clinic Ltd | Other services | 2025 |
| Cavendish Exchange Ltd | Wholesale & retail | 2018 |
| CBB Property and Maintenance Consultants LLP | | 2020 |
| CBI Ltd | Hospitality | 2025 |