| Copper Hill Workshop Ltd | Arts & recreation | 2021 |
| Copperoak Plumbing Services Ltd | Construction | 2026 |
| Copperoak Property Services Limited | Administrative & support | 2010 |
| Corebox Fulfill Ltd | Wholesale & retail | 2025 |
| Cormack Paving Limited | Construction | 2008 |
| Cornerstone Build South East Limited | Construction | 2026 |
| Cornish Surfacing Ltd | Construction | 2025 |
| Corpix Photography Limited | Professional & scientific | 2015 |
| Corpus Fitness Ltd | Arts & recreation | 2011 |
| CORREL8 Digital Limited | Information & communication | 2025 |
| Cosmic Feeling Ltd | Other services | 2013 |
| Costache Valeting & Detailing Ltd | Administrative & support | 2026 |
| Courtenay Construction Limited | Construction | 2023 |
| Covatel Ltd | Information & communication | 2011 |
| Covington Property Ltd | Real estate | 2021 |
| Cozy DEN Properties Ltd | Real estate | 2024 |
| CP Ministries UK | Other services | 2011 |
| CPM Properties Limited | Administrative & support | 2014 |
| CR3 Youth Project Limited | Arts & recreation | 2013 |
| CR6 Publishing Limited | Information & communication | 2007 |
| Craft Building Limited | Construction | 2025 |
| Craftsons Ltd | Real estate | 2021 |
| Craigmyle Glebe Limited | Arts & recreation | 1934 |
| Cranfields Accountancy Services Limited | Professional & scientific | 1998 |
| Crawley Auto Technik Ltd | Wholesale & retail | 2009 |
| Crawley Kitchen Facelift Company Ltd | Construction | 2023 |
| Creare (Surrey) Ltd | Construction | 2023 |
| Creating Lifesavers Limited | Health & social care | 2021 |
| Creative HR Services Ltd | Administrative & support | 2022 |
| Creed Contractors Limited | Administrative & support | 2020 |
| Creed Homes Albury Ltd | Real estate | 2023 |
| Creed Homes Limited | Administrative & support | 2011 |
| Creekside Interiors Limited | Construction | 2025 |
| Crest & Wren Limited | Real estate | 2026 |
| Crockett & Crockett Paving Ltd | Administrative & support | 2018 |
| Cromay Limited | Construction | 1985 |
| Cross Check Consultancy Ltd | Financial services | 2023 |
| Croudace Homes Group Limited | Construction | 2002 |
| Croudace Land Holdings Limited | Construction | 1961 |
| Croudace Limited | Professional & scientific | 1946 |
| Croudace Partnerships Limited | Construction | 2003 |
| Croudace Portland Limited | Construction | 1983 |
| Croudace Strategic Limited | Construction | 2005 |
| Crowe Plant Fabrication Limited | Construction | 1978 |
| Crowe Scaffolding Services Limited | Extraterritorial | 2011 |
| Crown & Pepper Caterham Ltd | Hospitality | 2016 |
| Crown Caterham Delivery Limited | Hospitality | 2025 |
| Crown Caterham Foods Limited | Hospitality | 2025 |
| Crown Caterham Takeaway Limited | Hospitality | 2025 |
| Croydon Gymnastics Club CIC | Arts & recreation | 2020 |
| Croydons Publishers Limited | Information & communication | 2018 |
| Cruise 4 Sports Limited | Transport & logistics | 2014 |
| Crux Farms Ltd | Agriculture & fishing | 2024 |
| Crystal Carpets CR3 Limited | Wholesale & retail | 2018 |
| Crystal Manifestations Ltd | Wholesale & retail | 2021 |
| Crystal Property Maintenance and Waste Management Ltd | Households | 2022 |
| CSE Crosscom Limited | Other services | 1992 |
| Csection Correction Ltd | Other services | 2022 |
| Csri Academy of Excellence Limited | Other services | 2010 |
| Cullen & SON Travel Ltd | Administrative & support | 2025 |
| Cultlab Creative Hub Ltd | Information & communication | 2025 |
| Cultlab Limited | Arts & recreation | 2022 |
| Custom Solutions Trading Ltd | Manufacturing | 2026 |
| Cutbyjoe Ltd | Information & communication | 2019 |
| D & N Property Management Limited | Real estate | 2017 |
| D a Lindsay & Sons Limited | Other services | 2009 |
| D and B Access Solutions Ltd | Construction | 2021 |
| D C Boilers & Maintenance Ltd | Professional & scientific | 2020 |
| D Doherty Roofing Services Ltd | Construction | 2013 |
| D M Associates (Accountants) Ltd. | Professional & scientific | 2000 |
| D M Properties Limited | Real estate | 2011 |
| D N Still Limited | Construction | 2015 |
| D S Taylor Limited | Administrative & support | 2008 |
| D Wilkinson Consultants Limited | Professional & scientific | 2009 |
| D. Price Electrical Ltd | Construction | 2015 |
| D.L.Gillam Quality 1ST Ltd | Construction | 2026 |
| Daedalus Investments Limited | Other services | 2002 |
| Daisy Chain PRE School Old Coulsdon LLP | | 2024 |
| Daisy's Bear Limited | Construction | 2012 |
| Damp Proofing London South Limited | Construction | 2010 |
| DAN Jordan Publishing Ltd | Information & communication | 2007 |
| Danny Ellis Limited | Information & communication | 2013 |
| Dans MON SAC Limited | Wholesale & retail | 2019 |
| Dansk Construction Limited | Construction | 2015 |
| Dappa MRP Flooring Limited | Other services | 2009 |
| Datascore Limited | Real estate | 1988 |
| Datatribes Limited | Information & communication | 2024 |
| David Ciccone Architects Limited | Professional & scientific | 2018 |
| David Ciccone Developments Limited | Construction | 2018 |
| Dayski Ltd | Construction | 2019 |
| DB Botanical Tonics Limited | Professional & scientific | 2026 |
| DB Property Finance Limited | Financial services | 2026 |
| DB Soundproofing Limited | Construction | 2023 |
| DC Highways Traffic Limited | Administrative & support | 2025 |
| DC Telecoms Rigging Ltd | Information & communication | 2020 |
| DCH Insightful Commercial Consulting Ltd | Professional & scientific | 2025 |
| Ddeducation Ltd | Education | 2025 |
| Dealyn Enterprises Limited | Hospitality | 2005 |
| Dean Ayling Limited | Construction | 2017 |
| Debwiz Limited | Manufacturing | 2024 |