| Carlton Fire & Safety Services Limited | Administrative & support | 2004 |
| Carly Logistics Limited | Transport & logistics | 2025 |
| Carnivore Foods Limited | Wholesale & retail | 2011 |
| Carob Tree Estates Limited | Administrative & support | 2018 |
| Carolina Brooks Limited | Professional & scientific | 2018 |
| Carpentry Co - Developments Limited | Construction | 2020 |
| Carr Gorey Ltd | Real estate | 2024 |
| Carterhold Ltd | Financial services | 2024 |
| Casa Litore Ltd | Real estate | 2026 |
| Casamance Limited | Manufacturing | 1998 |
| Casarrubias Consiglieri Limited | Information & communication | 2024 |
| Caseysschoolwear Ltd | Wholesale & retail | 2015 |
| Cash Allan Properties Ltd | Real estate | 2020 |
| Cask and KEG Limited | Hospitality | 2008 |
| Cast Services Limited | Administrative & support | 2016 |
| Catalina Swinburn Studio Limited | Administrative & support | 2022 |
| Catch Cafe Ltd | Wholesale & retail | 2019 |
| Caterham Chippy Limited | Hospitality | 2025 |
| Caterham Fish Bar Limited | Professional & scientific | 2020 |
| Catering First Limited | Hospitality | 2019 |
| Catford Roofing Ltd | Construction | 2025 |
| Cathal Wynne Associates Limited | Administrative & support | 2011 |
| Catkind Ltd | Professional & scientific | 2024 |
| Cavelle Signature Homes Ltd | Real estate | 2026 |
| Cavendish Plumbing & Construction Ltd. | Construction | 2010 |
| Cavendish School Limited | Administrative & support | 1999 |
| CBL Stone Renovations Ltd | Construction | 2023 |
| Cbrh Property Group Ltd | Real estate | 2024 |
| Cbuk Events Limited | Arts & recreation | 2016 |
| CC the Plumber Limited | Construction | 2024 |
| CCB (Thai) Limited | Hospitality | 2024 |
| Cceventsuk Ltd | Wholesale & retail | 2023 |
| CCG Construction Limited | Construction | 2026 |
| CCM Payments Limited | Administrative & support | 2019 |
| CCR Plumbing and Heating Ltd | Construction | 2022 |
| CDA, Creative Design Advertising Limited | Professional & scientific | 1974 |
| CDL Interiors Ltd | Construction | 2024 |
| CDL Medical Limited | Health & social care | 2020 |
| CDO Brighton Road Ltd | Construction | 2022 |
| CDO Developments London Ltd | Construction | 2021 |
| CDO Drug Development Services Limited | Professional & scientific | 2025 |
| CDO Holdings Limited | Financial services | 2024 |
| CDO Safa Limited | Real estate | 2024 |
| CDS Services Ltd | Water & waste | 2021 |
| Cedconsult Ltd | Professional & scientific | 2013 |
| Cedhomes Ltd | Real estate | 2020 |
| Cego Properties Limited | Real estate | 2018 |
| Cekic Fish Bar Limited | Hospitality | 2021 |
| Celibless Ltd | Construction | 2026 |
| Cell-X Talent Limited | Administrative & support | 2021 |
| Central Fire Solutions Limited | Construction | 2023 |
| Central Parade Fish Bar Limited | Hospitality | 2016 |
| Centre Stage Solutions Limited | Arts & recreation | 2018 |
| Centric Comms Ltd | Information & communication | 2019 |
| Century Restorations Ltd | Other services | 2019 |
| Cephas Williams Ltd | Arts & recreation | 2020 |
| Ceres View Management Co Limited | Households | 2016 |
| Certifyglobal Ltd | Education | 2025 |
| Certus Aurum Capital Ltd | Administrative & support | 2024 |
| Cezar Interiors Ltd | Construction | 2016 |
| CFS TV Ltd | Administrative & support | 2024 |
| Chafrenn Property Services Limited | Real estate | 2023 |
| Chailey Close Management Company Limited | Households | 2019 |
| Chalice Property Solutions Limited | Real estate | 2024 |
| Chambercombe Trading Limited | Arts & recreation | 1995 |
| Chambers Guilfoyle Limited | Wholesale & retail | 2015 |
| Change in Motion Ltd | Education | 2022 |
| CHANGE24 Ltd | Construction | 2024 |
| Changing Rooms Home Improvements Ltd | Administrative & support | 2010 |
| Charles F E Limited | Construction | 2024 |
| Charles George Services Limited | Construction | 2021 |
| Charlesdaniel Fine Finishes Ltd | Construction | 2023 |
| Charlie Maunsell Ltd | Administrative & support | 2017 |
| Charliez Barberz Limited | Other services | 2023 |
| Charlotte Tracy Consultancy Ltd | Professional & scientific | 2009 |
| Charmed Life Limited | Wholesale & retail | 2023 |
| Charmwood Developments Ltd | Other services | 2016 |
| Charnley Communications Ltd | Professional & scientific | 2017 |
| Charter Oak Property Services Limited | Households | 1986 |
| Charter Services (UK) Ltd | Administrative & support | 2001 |
| Charterhouse Surveying Ltd | Professional & scientific | 2017 |
| Chartes Surveyors Limited | Construction | 2013 |
| Charybdis Limited | Professional & scientific | 2003 |
| Chase and Matthew Properties Limited | Real estate | 2024 |
| Chattertons Estate Agents Ltd | Administrative & support | 2008 |
| Chaudry and Sons Property Ltd | Real estate | 2010 |
| Chayesey Ltd. | Administrative & support | 2015 |
| Cheapsites Ltd | Wholesale & retail | 2026 |
| Cheeks of Bexley Limited | Administrative & support | 2009 |
| Cheerwise Limited | Real estate | 1985 |
| Chefs in Schools | Education | 2018 |
| Chefs Kitchen Sidcup Limited | Hospitality | 2019 |
| Chelmsford Property Limited | Households | 2014 |
| Chelsea Blue Properties Ltd | Real estate | 2026 |
| Chelsea Tech Europe Limited | Information & communication | 2025 |
| Chelsfield Cricket Club 1731 Ltd | Wholesale & retail | 2024 |
| Cheque Mate Solutions Limited | Wholesale & retail | 2007 |
| Cherry Pearl Investments Limited | Professional & scientific | 2024 |
| Cherry Tree Engineering Ltd | Professional & scientific | 2026 |
| Cherrybrook Consultants Ltd | Administrative & support | 2007 |