| Club Kick Ltd | Arts & recreation | 2017 |
| CML66 Limited | Professional & scientific | 2026 |
| Co Space Limited | Real estate | 2019 |
| Coins 4 Clubs Limited | Wholesale & retail | 2022 |
| Colby Capital Management Limited | Financial services | 2026 |
| Colby Capital Partners Limited | Financial services | 2026 |
| Coldham Works Limited | Information & communication | 2005 |
| Collings Storage Limited | Transport & logistics | 2014 |
| Collins Scaffolding Group Ltd | Construction | 2026 |
| Colne Capital Limited | Construction | 2014 |
| Comber Grove Estates Ltd | Real estate | 2024 |
| Complete Lifting Services Limited | Construction | 2018 |
| Complete Safety Solutions Ltd | Professional & scientific | 2025 |
| Conquest Garages Limited | Real estate | 1970 |
| Considered Mortgage Solutions Ltd | Financial services | 2020 |
| Construct-Design Ltd | Construction | 2018 |
| Constructive Space Ltd | Construction | 2014 |
| Convergent Home Technologies Limited | Information & communication | 2004 |
| Cooltowel Ltd | Wholesale & retail | 2025 |
| Copeland House Limited | Real estate | 2017 |
| Corwell Limited | Professional & scientific | 2019 |
| Cough Drop Properties Ltd | Households | 2024 |
| CPI Properties Limited | Real estate | 2023 |
| CPM Freight Solutions (UK) Ltd | Transport & logistics | 2021 |
| Create Room Limited | Construction | 2013 |
| Creative Car Products UK Ltd. | Professional & scientific | 2015 |
| Crete Fleet Ltd | Manufacturing | 2025 |
| Crownfield Consulting Ltd | Professional & scientific | 2026 |
| Crownland Pictures Limited | Information & communication | 2024 |
| CT Real Estate Limited | Real estate | 2020 |
| CTG Express Ltd | Transport & logistics | 2020 |
| Culleywood Ltd | Health & social care | 2016 |
| Cumulus Investment Solutions Limited | Financial services | 2012 |
| Cygo Ltd | Wholesale & retail | 2025 |
| D & L Driveways Ltd | Construction | 2013 |
| D and L Landscapes 2020 Limited | Administrative & support | 2020 |
| D I Holdings Ltd | Financial services | 2015 |
| D J Plant Limited | Administrative & support | 2016 |
| D&G Cladding Systems Limited | Manufacturing | 2004 |
| D&J COX Property Limited | Real estate | 2019 |
| D&M Grab Hire Ltd | Transport & logistics | 2019 |
| D.A. Moody (Nominees) Limited | Other services | 1970 |
| Dabhoc Consultancy Ltd | Information & communication | 2011 |
| DAK Dog Academy Ltd | Education | 2026 |
| DAK Doggy Day Care & Grooming Ltd | Agriculture & fishing | 2026 |
| DAK Equipment Limited | Wholesale & retail | 2024 |
| DAK Performance Ltd | Administrative & support | 2026 |
| DAK Property Services Ltd | Real estate | 2024 |
| DAK Security Ltd | Administrative & support | 2023 |
| Daletrove Limited | Real estate | 1988 |
| Daniels Landscapes Limited | Administrative & support | 2017 |
| Darcy Bunnie Creative Arts Limited | Real estate | 2011 |
| Darren Miller HR Associates Limited | Administrative & support | 2018 |
| Data HQ Holdings Ltd | Administrative & support | 2005 |
| Data HQ Limited | Information & communication | 2001 |
| Datastream Technologies Limited | Information & communication | 2023 |
| Dbph Limited | Real estate | 2017 |
| DC Cleaners Group Limited | Administrative & support | 2012 |
| Ddlm Property Investments Ltd | Real estate | 2019 |
| Debneys Limited | Financial services | 2020 |
| Deep Science Ventures Limited | Professional & scientific | 2016 |
| Delamas Properties Limited | Households | 1961 |
| Delphiqa Limited | Information & communication | 2024 |
| Denham Services Limited | Construction | 2020 |
| Desert Dog Consulting Limited | Administrative & support | 2016 |
| Devoted Events Ltd | Arts & recreation | 2021 |
| DGL (Projects) Ltd | Manufacturing | 2019 |
| Diabetic EYE Screening Limited | Other services | 2021 |
| Dilloway Aggregates Limited | Mining & quarrying | 2019 |
| Dilloway Developments Ltd | Construction | 2022 |
| Direct Drainage Solutions London Limited | Construction | 2025 |
| Direct Roofing Developments Ltd | Construction | 2021 |
| Discount Builders Merchants Limited | Wholesale & retail | 1988 |
| Dj's Plumbing Services Limited | Construction | 2024 |
| DJM Corporate Advisory Ltd | Professional & scientific | 2025 |
| DM Investment Group Limited | Financial services | 2017 |
| DNA and Sons Ltd | Professional & scientific | 2020 |
| DOC Cleaning (Holdings) Limited | Financial services | 2025 |
| Docklands Telecom Centre Limited | Information & communication | 1997 |
| Doel Engineering (DC) Ltd | Professional & scientific | 2024 |
| Donald Moody Investments and Developments Limited | Real estate | 1972 |
| Donatantonio Investments Ltd | Financial services | 2014 |
| Dooh Media Limited | Professional & scientific | 2016 |
| Double Green Limited | Water & waste | 2025 |
| DR Belloy VET Ltd | Financial services | 2024 |
| DR Emma Cathcart Limited | Health & social care | 2020 |
| DR LJ Jones Ltd | Financial services | 2024 |
| Drill Wholesale Limited | Wholesale & retail | 2018 |
| Drnt Ltd | Professional & scientific | 2025 |
| Dsgc Holdings Limited | Professional & scientific | 2020 |
| DT Nails Spa Ltd | Other services | 2024 |
| Duane Street Limited | Construction | 2012 |
| Dunsvalley Associates Limited | Hospitality | 1991 |
| Durrants Farm Masts Ltd | Agriculture & fishing | 2021 |
| Dutchproperty Ltd | Real estate | 2020 |
| E & E Property & Investment Limited | Real estate | 2019 |
| E B Whelan Prop 1 Ltd | Real estate | 2019 |
| E King and SON Construction Limited | Administrative & support | 2016 |
| E.K. Young Lightning Protection Limited | Construction | 2021 |
| Eabc Education Ltd | Education | 2017 |