| C B W Developers Limited | Construction | 1998 |
| C Braybrook Plumbing Heating & Renewables Limited | Construction | 2026 |
| C Bull Swimming Limited | Arts & recreation | 2011 |
| C J Nimmo Limited | Construction | 2013 |
| C&K Limited | Real estate | 2018 |
| C.J.C.(Electrical)Limited | Manufacturing | 1964 |
| C.R.C Mechanical & Electrical Ltd | Administrative & support | 2017 |
| Cadastral Corporation Limited(The) | Administrative & support | 1987 |
| Cadogan Wilson Limited | Financial services | 2001 |
| Caerus Properties Ltd | Real estate | 2001 |
| Camp Casa UK LLP | | 2025 |
| Canvaa Ltd | Professional & scientific | 2025 |
| Capital Construction Projects Ltd | Construction | 2018 |
| Capital PR Limited | Professional & scientific | 2024 |
| Capital Risk Consultancy Ltd | Financial services | 2025 |
| Carbon Craft Ltd | Professional & scientific | 2024 |
| Card Connoisseurs Ltd | Wholesale & retail | 2025 |
| Care Epsom & Reigate Limited | Health & social care | 2023 |
| Care More Franchising Limited | Professional & scientific | 2023 |
| Care More Limited | Health & social care | 2014 |
| Carenection Ltd | Health & social care | 2025 |
| Carlisle Road (Hove) Management Company Limited | Real estate | 2008 |
| Carnah Events Limited | Information & communication | 2016 |
| Caroline Investments Ltd | Real estate | 1999 |
| Caspian Building London Ltd | Construction | 2022 |
| Cast Registrars Limited | Administrative & support | 2002 |
| Castlelost Investments Limited | Real estate | 2024 |
| Cataract-Doctor Limited | Health & social care | 2023 |
| Cavix UK Ltd | Professional & scientific | 2024 |
| CD Smile Studios Limited | Health & social care | 2019 |
| Cedarmarsh Limited | Real estate | 1999 |
| Cedars Health Ltd | Financial services | 2018 |
| CEI Housing Consultancy Limited | Professional & scientific | 2015 |
| Central Heating Solutions Ltd | Construction | 2023 |
| Certified Advice Limited | Professional & scientific | 2020 |
| Chalk Futures Limited | Information & communication | 2019 |
| Charlie Newman Limited | Real estate | 2001 |
| Charter Court (New Malden) Limited | Real estate | 2015 |
| Chequers Lane Garage Limited | Wholesale & retail | 2004 |
| Chessington Hall Estate,Limited | Real estate | 1933 |
| Chetts Carpentry Ltd | Construction | 2022 |
| Chipaca Ltd | Information & communication | 2020 |
| Chirpy Thoughts Limited | Wholesale & retail | 2014 |
| Christopher Safety Products Limited | Professional & scientific | 1982 |
| CIH South East Limited | Other services | 2012 |
| CJC Electrical Installation Limited | Wholesale & retail | 2014 |
| Claire Langham Creative Ltd | Professional & scientific | 2023 |
| Claris Pharma Ltd | Professional & scientific | 2025 |
| Clarity Pools UK Ltd | Administrative & support | 2025 |
| Clark Football Languages Limited | Professional & scientific | 2004 |
| Clarkes Garden SERVICES24 Ltd | Administrative & support | 2025 |
| Clarkey's Properties Ltd | Real estate | 2022 |
| Cn-D Web Services Limited | Information & communication | 2019 |
| Coaching for Aspirations Limited | Extraterritorial | 2023 |
| Cogent Associates Limited | Professional & scientific | 2019 |
| Collective Carpentry and Construction Ltd | Construction | 2023 |
| Collingwood Way Ltd | Hospitality | 2006 |
| Collis and Campbell Ltd | Wholesale & retail | 2024 |
| Collison & Co Building Contractors Ltd | Construction | 2022 |
| Colwood Demolition and Site Services Ltd | Construction | 2022 |
| Construction and Waste Management London Ltd | Construction | 2023 |
| Coopers GIN Ltd | Manufacturing | 2024 |
| Coordinatours Ltd | Administrative & support | 2010 |
| Corebuilt Search Ltd | Administrative & support | 2026 |
| Corsica Freehold Limited | Households | 2025 |
| CPF Group Ltd | Administrative & support | 2018 |
| Craigellachie Arcbairn LLP | | 2025 |
| Credit Management Resources Limited | Real estate | 1990 |
| Crestmar Marine Insurance Services Ltd | Financial services | 1999 |
| Crewe Court Management Limited | Real estate | 2016 |
| CRM by Design Ltd | Information & communication | 2013 |
| Crosby Simmons Consultancy Limited | Professional & scientific | 2023 |
| Crown House (Tadworth) Limited | Real estate | 1980 |
| Curzon Property Developments Ltd | Construction | 2006 |
| Cybalon Limited | Information & communication | 2017 |
| Cyber Detect Consulting Limited | Information & communication | 2026 |
| Dacroft Limited | Professional & scientific | 2014 |
| Daugirdas M Limited | Manufacturing | 2024 |
| Dawcroft Quality Decorators Ltd | Construction | 1996 |
| Dawe & Dawe Limited | Financial services | 2018 |
| Dawson One Limited | Real estate | 2007 |
| Dawsons Ventures Ltd | Professional & scientific | 2026 |
| Daydream Forest Limited | Agriculture & fishing | 2010 |
| DC Construction & Maintenance Limited | Construction | 2014 |
| DC Construction Properties Ltd | Real estate | 2022 |
| Dedication Services Limited | Professional & scientific | 2024 |
| Deirdre Dwyer Limited | Other services | 2011 |
| Delens 2 Ltd | Real estate | 2019 |
| Derek Pobjoy Investments Limited | Manufacturing | 1969 |
| Destiny 4A Limited | Real estate | 2017 |
| Devgun Limited | Construction | 2014 |
| Devlin Financial Ltd | Financial services | 2020 |
| Devlin Homes Ltd | Construction | 2020 |
| Devonport Plumbing & Heating Ltd | Construction | 2022 |
| Dgmuk Ltd | Construction | 2025 |
| DGR Scaffolding Ltd | Construction | 2025 |
| DHL Accountancy Services Limited | Professional & scientific | 2022 |
| DHS Limited | Health & social care | 2001 |
| Diamond Grab Hire Limited | Water & waste | 2015 |
| Diamond Premium Ltd | Construction | 2018 |