| Cacao Cafe Limited | Hospitality | 2022 |
| Caen Consulting Ltd | Professional & scientific | 2023 |
| Caird Property Management Ltd | Real estate | 2020 |
| Cala (Esop) Trustees Limited | Financial services | 1996 |
| Cala 1 Limited | Construction | 2013 |
| Cala Group (Holdings) Limited | Construction | 2013 |
| Cala Homes Communities (Arborfield) Limited | Construction | 2017 |
| Cala Homes Communities (Crowthorne) Limited | Construction | 2017 |
| Cala Homes Communities (Didcot) Limited | Construction | 2019 |
| Cala Homes Communities (Shrivenham) Limited | Construction | 2017 |
| Cala Homes Communities Limited | Construction | 2016 |
| Callidus Tutors Ltd | Education | 2022 |
| Callington UK Limited | Wholesale & retail | 2014 |
| CAM Operations Ltd | Administrative & support | 2019 |
| Cameron School of Motoring Ltd | Education | 2025 |
| Canaan Christian Ministries | Wholesale & retail | 2017 |
| Capital Business Events Limited | Administrative & support | 2005 |
| Capital Construction Services Limited | Construction | 2015 |
| Capital Metals Recycling Ltd | Water & waste | 2019 |
| Capitol Car Wash Limited | Administrative & support | 2006 |
| Capstone Consulting Ltd | Professional & scientific | 2025 |
| Car Zone Staines Ltd | Wholesale & retail | 2025 |
| Care SOLUTION01 Ltd | Health & social care | 2023 |
| Caresiweb Ltd | Information & communication | 2015 |
| Cargo Junction London Limited | Wholesale & retail | 2023 |
| Cargo-Tech Consultancy Ltd | Information & communication | 2025 |
| Cargohub Logistics Ltd | Transport & logistics | 2024 |
| Carisbrooke Consultancy UK Limited | Administrative & support | 2004 |
| Carl Louise Marina Ltd | Construction | 2025 |
| Carlson Models Limited | Manufacturing | 2016 |
| Carlton Court (Staines) Management Company Limited | Households | 1974 |
| Carlyle Square Ltd | Real estate | 2019 |
| Carrventures Ltd | Hospitality | 2025 |
| Case Creation Limited | Manufacturing | 2013 |
| Case Toscana Limited | Real estate | 1998 |
| Caspr Ltd | Information & communication | 2024 |
| Castle Mews (Weybridge) Residents Management Company Limited | Households | 2006 |
| Cat Sales & Marketing Limited | Administrative & support | 2014 |
| Catalaovending Ltd | Transport & logistics | 2024 |
| Catalin Construction Services Limited | Construction | 2019 |
| Catau Construction Limited | Construction | 2019 |
| Catena Dwellings Limited | Real estate | 2017 |
| Cathay London Ltd | Wholesale & retail | 2012 |
| Catostar Ltd | Health & social care | 2024 |
| Caviar Fresh Fish Limited | Wholesale & retail | 2022 |
| CBR Transport&Service Ltd | Transport & logistics | 2025 |
| Cbswiftfix Plumbing and Heating Limited | Construction | 2025 |
| CC Management RTM Company Limited | Extraterritorial | 2025 |
| Cctv Wala Ltd | Administrative & support | 2021 |
| CEG Brickwork Contractors Ltd | Construction | 2018 |
| CEG Construction Ltd | Construction | 2025 |
| Celerant UK Holdco Limited | Financial services | 2024 |
| Celeste Healthcare Limited | Health & social care | 2026 |
| Celiberti Design Ltd | Real estate | 2006 |
| Centroller Properties Ltd | Real estate | 2020 |
| Cerestek Ltd | Information & communication | 2020 |
| Cernamak Limited | Construction | 2025 |
| Ceylon Foods Limited | Hospitality | 2020 |
| Cezar Trans-Logistics Ltd | Transport & logistics | 2015 |
| Chakraborty IT Limited | Information & communication | 2019 |
| Champion Energy Ltd | Professional & scientific | 2025 |
| Channelserve Limited | Information & communication | 2007 |
| Chapatti Inc Ltd | Information & communication | 2023 |
| Chapter One Recovery Ltd | Health & social care | 2018 |
| Charles Court (Ashford) Management Limited | Households | 1997 |
| Charlie Newell Limited | Construction | 2021 |
| Charlotte's Compassionate Care Services Ltd | Health & social care | 2021 |
| Chase Property Group Ltd | Real estate | 2017 |
| Cheap&Easy Ltd | Wholesale & retail | 2024 |
| Cheat Sheets Ltd | Information & communication | 2026 |
| Cheche Productions Limited | Arts & recreation | 2021 |
| Chedsar Limited | Other services | 2008 |
| Cheetah Travel (Surrey) Limited | Transport & logistics | 2017 |
| Chefcatering Limited | Hospitality | 2025 |
| Cherry Orchard Freehold Limited | Households | 2008 |
| Cheung Kong International Limited | Wholesale & retail | 2026 |
| Chimotec Services Limited | Information & communication | 2020 |
| CHO1CE4U Ltd | Manufacturing | 2023 |
| Chosen 4 Greatness Ltd | Arts & recreation | 2024 |
| Chosen Accountants Ltd | Professional & scientific | 2026 |
| Chosen Clinic Ltd | Health & social care | 2025 |
| Chosen Gains Ltd | Arts & recreation | 2024 |
| Chosen Gym Limited | Arts & recreation | 2026 |
| CHR Consulting Limited | Information & communication | 2015 |
| Christopher David Design Limited | Professional & scientific | 2020 |
| Christopher David Developments Limited | Real estate | 2026 |
| Churchview Care Ltd | Health & social care | 2006 |
| Cibi Investments Limited | Construction | 1996 |
| City of London Recycling Limited | Water & waste | 2013 |
| CK Education Ltd | Education | 2025 |
| CKC Property Investments Ltd | Real estate | 2018 |
| Clar Constructions Ltd | Construction | 2024 |
| Clara Terra Limited | Wholesale & retail | 2025 |
| Clarence Grill Ltd | Hospitality | 2024 |
| Clarity Labs Ltd | Professional & scientific | 2025 |
| Clarod Limited | Transport & logistics | 2018 |
| Classic Crust Limited | Hospitality | 2004 |
| Claudel Transport Limited | Transport & logistics | 2018 |
| Claudia's Bakery Ltd | Hospitality | 2019 |
| Claudio Celiberti Limited | Construction | 2001 |