| Brindley Wilson Limited | Professional & scientific | 2003 |
| BRN Motor Services Ltd | Wholesale & retail | 2021 |
| Bulls Green Associates Limited | Professional & scientific | 2010 |
| Buntingford Joinery Limited | Manufacturing | 2006 |
| Byron Holdings Limited | Professional & scientific | 2017 |
| Byron Properties Limited | Real estate | 2005 |
| C & R Investments Holdings Limited | Financial services | 2019 |
| C B Couriers Ltd | Transport & logistics | 2002 |
| Cahoot Creative Limited | Professional & scientific | 2011 |
| Camstar Limited | Education | 2020 |
| Canada Wood LOG Construction Ltd | Construction | 2012 |
| Canonford Ltd | Administrative & support | 2003 |
| Capital Tyre Services Ltd | Wholesale & retail | 2026 |
| Car Wrap 24 Ltd | Other services | 2022 |
| Carson Property Services Limited | Construction | 2017 |
| Casam Group Ltd | Wholesale & retail | 2024 |
| Case Business Software Ltd. | Information & communication | 2009 |
| Case Pizza Ltd | Hospitality | 2024 |
| Case Property Letting Limited | Real estate | 2021 |
| Castlerake Properties Ltd | Administrative & support | 1999 |
| Castles Franchising Limited | Real estate | 1995 |
| Cavaja Consulting Limited | Professional & scientific | 2008 |
| Cavalleria Ltd | Construction | 2009 |
| CC Choices Limited | Professional & scientific | 2019 |
| CDG Services (Middlesex) Limited | Construction | 2024 |
| Celebrify Limited | Hospitality | 2024 |
| Centra Security Systems (UK) Limited | Administrative & support | 2016 |
| Centre for Transnational Education Ltd | Education | 2026 |
| Century Mobile Limited | Wholesale & retail | 2014 |
| Charterhouse (Enfield) Limited | Real estate | 2016 |
| Chequers Way (Palmers Green) Management Company Limited | Households | 2006 |
| Cheshunt Autos Ltd | Wholesale & retail | 2025 |
| Cheshunt Bathroom Centre Limited | Wholesale & retail | 2002 |
| Cheshunt Community Sports Park Ltd | Arts & recreation | 2020 |
| Cheshunt Counselling C.I.C. | Health & social care | 2015 |
| Cheshunt GAS Services Ltd | Construction | 2019 |
| Cheshunt Sports & Leisure Limited | Arts & recreation | 2011 |
| Cheshunt Store Ltd | Wholesale & retail | 2017 |
| Christian Electrical Services Ltd | Energy | 2021 |
| Churchill and Co Property Management Limited | Real estate | 2023 |
| Chutney Various Limited | Information & communication | 2012 |
| Cipher QA Limited | Professional & scientific | 2024 |
| City Gate House Management Company Limited | Households | 2006 |
| City Maritime Consultancy Limited | Professional & scientific | 2010 |
| Civilised Surveying Services Ltd | Professional & scientific | 2020 |
| Clarenborne Management Limited | Households | 1985 |
| Cleous Bites Kitchen Ltd | Hospitality | 2024 |
| Clipperton Company Limited | Real estate | 1988 |
| CNS Nails Ltd | Other services | 2026 |
| Coffee & Bagel Estates Limited | Real estate | 2019 |
| Cole Green Export Co. Limited | Wholesale & retail | 1980 |
| Coleman Bros. Group Limited | Professional & scientific | 1994 |
| Comet Square Phase Two Block Management Company Limited | Households | 2005 |
| Connectifai Ltd | Information & communication | 2024 |
| Container Storage Cambridge Ltd | Transport & logistics | 2020 |
| Container Storage Group Ltd | Transport & logistics | 2020 |
| Cookson Services Limited | Administrative & support | 2015 |
| Coombelands Road Management Company Limited | Households | 2011 |
| Copiertec Limited | Administrative & support | 1998 |
| Cornell Decorators Ltd | Other services | 2003 |
| Cornhill Lettings Limited | Real estate | 2019 |
| County & City Two Limited | Construction | 2025 |
| Courtney Property Holdings Ltd | Real estate | 2023 |
| COX Electrical Limited | Construction | 2001 |
| Create AV ( International ) Ltd | Administrative & support | 2015 |
| Creative Artwork & Illustration Limited | Arts & recreation | 2010 |
| Cresthaven Properties Limited | Real estate | 2016 |
| Crossbreed Music Limited | Information & communication | 2016 |
| Cuffley Cutters Limited | Administrative & support | 1980 |
| Cultural Care Homes Ltd | Health & social care | 2025 |
| Curly Vision Limited | Other services | 2016 |
| Cushway-Schmidt Limited | Manufacturing | 2010 |
| Cyberlutions Limited | Information & communication | 2008 |
| Cymtrex Limited | Construction | 2002 |
| Cypriot Street Food Ltd | Hospitality | 2024 |
| D Barclay Limited | Construction | 2002 |
| D-Mech Holdings Ltd | Real estate | 2025 |
| DAD in Paws Limited | Professional & scientific | 2016 |
| Dale Hunter Investments Ltd | Real estate | 2016 |
| Daly Holdings Limited | Financial services | 2014 |
| Dancecrazy Studios London Ltd | Education | 2019 |
| Daniel Howden Ltd | Extraterritorial | 2025 |
| Datum Building Consultancy Ltd. | Professional & scientific | 2010 |
| David Porter & Associates Limited | Professional & scientific | 1997 |
| Davnick Limited | Manufacturing | 2012 |
| Ddgg Ltd | Transport & logistics | 2023 |
| Dean Protain Limited | Construction | 2009 |
| Deepfield Road (Bracknell) Management Company Limited | Households | 2006 |
| Defined Developments Limited | Real estate | 2014 |
| Design by KMJ Limited | Professional & scientific | 2018 |
| DFS Building Ltd | Construction | 2020 |
| Digilec Limited | Construction | 2011 |
| Digit Labs Limited | Information & communication | 2025 |
| Direct Interiors 1988 Limited | Construction | 2008 |
| DJS Law Limited | Professional & scientific | 2015 |
| DMJ Construction Services Ltd | Construction | 2025 |
| DMK Enterprise Ltd | Wholesale & retail | 2017 |
| Dogan Testing Solutions Ltd | Information & communication | 2018 |
| Donovan Tyres Limited | Wholesale & retail | 1992 |
| Dowhall Properties Ltd | Other services | 2017 |