| Coincidentally Peoples Ltd | Manufacturing | 2024 |
| Coinshire Limited | Professional & scientific | 1983 |
| Colco Scientific Enterprises Limited | Professional & scientific | 1998 |
| Coldroom Contractors Ltd | Manufacturing | 2022 |
| Colgate (UK) Limited | Professional & scientific | 1974 |
| Colgate Holdings | Administrative & support | 1995 |
| Colgate-Palmolive (U.K.) Limited | Wholesale & retail | 1922 |
| Colgate-Palmolive Finance (UK) Limited | Financial services | 1993 |
| Colgate-Palmolive Investments (UK) Limited | Administrative & support | 2007 |
| Colin Berry Contracting Limited | Professional & scientific | 2023 |
| Coliston Ltd | Professional & scientific | 2003 |
| Collaborate Industries Limited | Real estate | 2015 |
| Collaborate Sales Performance Ltd | Professional & scientific | 2019 |
| Collaborative Development Ltd | Information & communication | 2014 |
| College Court (Woking) Management Company Limited | Households | 2011 |
| Collins Clan Limited | Financial services | 2025 |
| Colour Green Limited | Professional & scientific | 2010 |
| Colour Perfection Ltd | Wholesale & retail | 2011 |
| Colour Tech Bodyworx Ltd | Wholesale & retail | 2025 |
| Colourboxsigns Ltd | Manufacturing | 2015 |
| Colyer Group Limited | Administrative & support | 1995 |
| Colyer Phillips Ltd | Other services | 2015 |
| Colyer Repropoint Ltd | Other services | 2016 |
| Comfi AID Ltd. | Health & social care | 2011 |
| Comfort & Nourish Ltd | Wholesale & retail | 2015 |
| Commerce-Connections Limited | Information & communication | 2000 |
| Commoditiesinternational Ltd | Wholesale & retail | 2025 |
| Communitology Limited | Other services | 2025 |
| Community for Analytical Measurement Science | Professional & scientific | 2019 |
| Community Foundation for Surrey | Professional & scientific | 2005 |
| Comparaencasa Ltd. | Professional & scientific | 2009 |
| COMPASS4COUPLES Limited | Administrative & support | 2015 |
| Competitive Capabilities International UK Limited | Professional & scientific | 2017 |
| Complements of Nature Limited | Wholesale & retail | 1994 |
| Complete Amsterdam Ltd | Administrative & support | 2023 |
| Complete Company Services Limited | Professional & scientific | 1997 |
| Complete Pixels Limited | Extraterritorial | 2021 |
| Complete Sealants Ltd | Construction | 2018 |
| Complete Security Systems (Surrey) Limited | Administrative & support | 2006 |
| Compton Inns Ltd | Hospitality | 2025 |
| Compugraphics International Limited | Manufacturing | 1967 |
| Computer & Network Services GRP Ltd | Information & communication | 2009 |
| Concept Financial Management Limited | Financial services | 2001 |
| Conchelion Limited | Professional & scientific | 2025 |
| Concise Property Limited | Professional & scientific | 1992 |
| Condor Court (Management) Limited | Households | 1990 |
| Configured Content Solutions Limited | Information & communication | 2014 |
| Congress Services Limited | Professional & scientific | 1982 |
| Conita Consulting Limited | Information & communication | 2006 |
| Connaught Brass Ltd | Arts & recreation | 2026 |
| Connaught Gate Management Company Limited | Households | 2006 |
| Connaught House Management Limited | Extraterritorial | 1985 |
| Connect Consulting (Kingston) Ltd | Information & communication | 2009 |
| Connected Glow Ltd | Professional & scientific | 2025 |
| Connected Innovations EBT Limited | Professional & scientific | 2023 |
| Connected Innovations Limited | Professional & scientific | 2016 |
| Connected Market Research Limited | Professional & scientific | 2025 |
| Connectia Education Ltd | Education | 2019 |
| Connectia Ltd | Administrative & support | 2015 |
| Connecting Dots PVT Ltd | Information & communication | 2024 |
| Connections Courier Services (1986) Limited | Transport & logistics | 2004 |
| Connelly Sports Media Limited | Information & communication | 2012 |
| Connoisseur International Wines Limited | Extraterritorial | 2014 |
| Conquest Influence Ltd | Professional & scientific | 2023 |
| Conseo Board Review Limited | Professional & scientific | 2023 |
| Construction Ahead Ltd | Construction | 2014 |
| Construction Project Services UK Limited | Other services | 1996 |
| Construction Seven Ltd | Construction | 2021 |
| Consult Care Service Ltd | Other services | 2018 |
| Consulting and Design Ltd | Administrative & support | 2021 |
| Consulting International Ltd | Wholesale & retail | 2025 |
| Consulting Revolution Limited | Information & communication | 2015 |
| Consulting Structural Engineers Limited | Professional & scientific | 2005 |
| Container Trades Statistics Limited | Information & communication | 2008 |
| Contech Digital Consulting Ltd | Information & communication | 2023 |
| Content Pro Tech Ltd | Information & communication | 2016 |
| Continuity Planning Associates Ltd. | Information & communication | 1992 |
| Contractor Base Ltd | Information & communication | 2018 |
| Contrast Hairdressing Limited | Other services | 2011 |
| Contreversal Ltd | Extraterritorial | 2025 |
| Control Plant Limited | Manufacturing | 1977 |
| Conversations WH Ltd | Information & communication | 2019 |
| Convex Ecosystem Services Limited | Information & communication | 2022 |
| Convex Foundation Ltd | Information & communication | 2020 |
| Conway Darvell Ltd | Professional & scientific | 2026 |
| Cookridge Plotholders Limited | Real estate | 2012 |
| Cooper Capital Advisory Limited | Financial services | 2025 |
| Cooper Coding Ltd | Information & communication | 2025 |
| Cooper Dennison Holdings Limited | Professional & scientific | 2018 |
| Copper Coffee Roasters Limited | Manufacturing | 2020 |
| Copycat DIT Limited | Information & communication | 2024 |
| Corderoy Engineering Services Limited | Professional & scientific | 2024 |
| Core Essentials With Christiane Ltd | Health & social care | 2022 |
| Corinpark Developments Limited | Real estate | 2002 |
| Cornerstone Communicate Limited | Professional & scientific | 2014 |
| Cornerstone DBR Ltd | Construction | 2023 |
| Corporate Circus Ltd | Arts & recreation | 2024 |
| Corporate Systems and Services Solution Ltd | Administrative & support | 2025 |
| Corran Associates Limited | Professional & scientific | 2003 |
| Corran Consultancy Limited | Professional & scientific | 1999 |