| Clubhouse Fitness Limited | Arts & recreation | 2024 |
| Cobbles & Rhyme Productions 2 Ltd | Administrative & support | 2021 |
| Cobden Mews Management Company Limited | Administrative & support | 2013 |
| Coffee TW15 Ltd | Hospitality | 2019 |
| Colendi Setl Nominees Limited | Financial services | 2022 |
| Collaboration Nation Ltd | Professional & scientific | 2019 |
| Compass Design & Build Ltd | Construction | 2016 |
| Compmart Systems Limited | Information & communication | 2013 |
| Concept Commercial Flooring Limited | Construction | 2025 |
| Consultoria Europea Ltd | Professional & scientific | 2024 |
| Coombe Electrical Services Limited | Wholesale & retail | 1983 |
| Coorenexions Housing Limited | Real estate | 2024 |
| Core Equilibrium Ltd | Professional & scientific | 2018 |
| Coriwood Ltd | Agriculture & fishing | 2021 |
| Corporate Business Advisory Limited | Professional & scientific | 2024 |
| Corporate Wheels Ltd | Transport & logistics | 2024 |
| Cove Technology Limited | Manufacturing | 2009 |
| CPN Real Estate Ltd | Real estate | 2019 |
| Craiglane Property Management Limited | Real estate | 2005 |
| Crea Ltd | Other services | 2021 |
| Create International Limited | Other services | 2002 |
| Creative Film Makers Limited | Information & communication | 1964 |
| Creative Labourer Ltd | Construction | 2025 |
| Creative Productions Limited | Other services | 1956 |
| Crestoval Limited | Real estate | 2022 |
| Cricketwise Limited | Arts & recreation | 2022 |
| Cristina Aesthetics Limited | Other services | 2025 |
| Critical Talent Solutions Ltd | Administrative & support | 2022 |
| CRL Agency Limited | Professional & scientific | 2019 |
| Crossfit Shenley Ltd | Arts & recreation | 2024 |
| Crown Luxury Service Ltd | Transport & logistics | 2024 |
| Crpk Engineering Ltd | Manufacturing | 2024 |
| Cs.Me (UK) Limited | Health & social care | 2018 |
| CSM Property Services Ltd | Administrative & support | 2002 |
| CT Mews Limited | Real estate | 2014 |
| Cucumber Climate Control Ltd | Energy | 2018 |
| Culture Chest Limited | Education | 2023 |
| CW Metals Limited | Wholesale & retail | 2022 |
| Cyber Tsunami Ltd | Information & communication | 2020 |
| Cyberwave IT Limited | Information & communication | 2020 |
| D D P Healthcare Limited | Health & social care | 2025 |
| D Hair Ltd | Other services | 2023 |
| D Turgel Solutions Limited | Professional & scientific | 2021 |
| D. Korn (London) Limited | Real estate | 1961 |
| D.A.S Catering Services Ltd | Hospitality | 2019 |
| D4K Consulting Ltd | Professional & scientific | 2012 |
| D71 Ltd | Construction | 2023 |
| Danlen Limited | Real estate | 2025 |
| Darlington Ventures - Dame Ltd | Administrative & support | 2015 |
| Darnhills Limited | Real estate | 1984 |
| Dartmill Limited | Arts & recreation | 1983 |
| Data Nova Angels Ltd | Information & communication | 2026 |
| Data OPS Limited | Information & communication | 2015 |
| Davaar Properties Limited | Real estate | 2001 |
| Davis Bonley Limited | Professional & scientific | 2014 |
| Daylight Consulting Limited | Professional & scientific | 2023 |
| Daymark Advisory Limited | Professional & scientific | 2026 |
| DB EOT Trustees Limited | Professional & scientific | 2022 |
| DBL Actuarial Consultants Limited | Professional & scientific | 2026 |
| DBL Solutions Limited | Construction | 2024 |
| DBM Therma-Line Limited | Administrative & support | 1991 |
| Ddtm Ltd | Wholesale & retail | 2025 |
| DE Legibus Japan Limited | Professional & scientific | 2021 |
| Deep Water Blue Limited | Professional & scientific | 2002 |
| Dell Gardening Services Limited | Administrative & support | 2022 |
| DEN Chauffeur Ltd | Transport & logistics | 2024 |
| Dermazone Ltd | Other services | 2014 |
| Design Facility Limited | Administrative & support | 2000 |
| Deviesh Limited | Real estate | 2015 |
| DH Interactive Limited | Information & communication | 2006 |
| Dick and DON Limited | Financial services | 2009 |
| Dimond Plumbing Ltd | Construction | 2009 |
| Discrete Architectural Electronics Limited | Professional & scientific | 1998 |
| Distinct Physiotherapy Ltd | Health & social care | 2016 |
| Diva Luce International Ltd | Wholesale & retail | 2024 |
| Divas Boutique Limited | Wholesale & retail | 2018 |
| DJK Decorators Limited | Construction | 2015 |
| Djlk Limited | Real estate | 2024 |
| DK & N Sennik LLP | | 2022 |
| Dknt Properties Limited | Real estate | 2021 |
| DLV Properties Ltd | Real estate | 2021 |
| DO IT ALL Solutions Ltd | Construction | 2023 |
| Docnotes Ltd | Information & communication | 2020 |
| Dolphin Maritime & Aviation Services Limited | Professional & scientific | 1965 |
| Door Door Limited | Other services | 2022 |
| Dorda House Ltd | Real estate | 2017 |
| DR Peter H Winocour Medical Services Ltd | Health & social care | 2016 |
| DRD Carpentry & Construction Ltd | Information & communication | 2019 |
| Dreemz Wellness Limited | Wholesale & retail | 2025 |
| Drivana Chauffeurs Ltd | Transport & logistics | 2025 |
| Drivus Ltd | Transport & logistics | 2024 |
| Drml Consulting Ltd | Professional & scientific | 2023 |
| Drwh Limited | Real estate | 2004 |
| DS Events Limited | Administrative & support | 2017 |
| Dtmf Limited | Professional & scientific | 2025 |
| Duckworth & Co. Ltd | Wholesale & retail | 2025 |
| Dupler Limited | Information & communication | 2014 |
| Dust Limited | Information & communication | 2002 |
| Dust Media Group Ltd | Information & communication | 2015 |
| Dynamic Group Limited | Administrative & support | 2011 |