| Country PUB & Kitchen Limited | Hospitality | 2014 |
| County Constructions Limited | Real estate | 1995 |
| Cousin Associates Limited | Manufacturing | 2013 |
| CPB Twyford Limited | Extraterritorial | 2000 |
| CQK Holdings Limited | Financial services | 2024 |
| CQK Limited | Hospitality | 1960 |
| Cquence Robotics Ltd | Professional & scientific | 2025 |
| Craft Liquid Packaging Co Ltd | Manufacturing | 2025 |
| Crafty Kids Limited | Information & communication | 2001 |
| Crane Mead Property Developments Limited | Administrative & support | 2018 |
| Cranes Drink Ltd | Manufacturing | 2013 |
| Cranham House Freehold Management Ltd | Households | 2019 |
| Creating the Impossible Ltd | Information & communication | 2011 |
| Creation B Ltd | Information & communication | 2023 |
| Creative Cultivators Community Interest Company | Agriculture & fishing | 2024 |
| Creative Finishes Limited | Construction | 2013 |
| Creative Freedom Limited | Professional & scientific | 2002 |
| Creative Self Limited | Extraterritorial | 2018 |
| Cringlegrove Ltd | Health & social care | 2024 |
| Cripsey Brook Limited | Agriculture & fishing | 2007 |
| Crispinhill Properties Ltd | Administrative & support | 2013 |
| Criticalcardsuk Ltd | Wholesale & retail | 2025 |
| Crocus Projects Limited | Construction | 2025 |
| Cross House Communications Limited | Professional & scientific | 2026 |
| Crossover Group Limited | Administrative & support | 2001 |
| Crowther Estates Ltd | Real estate | 2017 |
| Croxton Park Farm Limited | Extraterritorial | 1993 |
| Cuda Investments Limited | Real estate | 2022 |
| Cuda Limited | Manufacturing | 1998 |
| Culra Management Limited | Hospitality | 2019 |
| Curait Ltd | Wholesale & retail | 2021 |
| Custerson Consulting Limited | Professional & scientific | 2020 |
| Customeyes.Me Ltd | Real estate | 2015 |
| CW Landscape Design Ltd | Administrative & support | 2016 |
| CWE Creative Limited | Professional & scientific | 2004 |
| CX International Holding Group Limited | Administrative & support | 2020 |
| Cycle Matter Ltd | Water & waste | 2025 |
| Cyclone Records Ltd | Information & communication | 2023 |
| Cynapses London Limited | Professional & scientific | 2015 |
| D & C Ceramics Limited | Construction | 2020 |
| D C Parrish & Sons Ltd | Agriculture & fishing | 2014 |
| D G F Engineering Limited | Manufacturing | 2005 |
| D H Smyth Limited | Professional & scientific | 2013 |
| D R and C a Stokes (Farming) Limited | Agriculture & fishing | 2016 |
| D Sherratt Roofing Limited | Construction | 2023 |
| D V & J a Pettitt Limited | Agriculture & fishing | 2014 |
| D Whiddett & Co Notarial Services Limited | Professional & scientific | 2011 |
| D&G Locksmith Services Ltd | Administrative & support | 2025 |
| D&Tc Services Limited | Transport & logistics | 2021 |
| D. & F. Miller & Sons Limited | | 1975 |
| D. Doherty Ltd | Construction | 2016 |
| D. M. Hodge Limited | Agriculture & fishing | 1959 |
| Daba Property Investment Limited | Real estate | 2016 |
| Dabify Ltd | Information & communication | 2023 |
| Daffodil Consulting LLP | | 2002 |
| Dafree CIC | Education | 2025 |
| DAH Management Limited | Construction | 2014 |
| Daisygrange Property Ltd | Construction | 2016 |
| Dalmir Ltd | Wholesale & retail | 2025 |
| Daloss Ltd | Hospitality | 2024 |
| DAN Ormerod Limited | Professional & scientific | 2003 |
| Danagrove Limited | Real estate | 1982 |
| Danciu Sorin Ltd | Manufacturing | 2026 |
| Darwin Systems Limited | Professional & scientific | 2024 |
| Data Inspired Living Ltd | Information & communication | 2025 |
| Data Protection Education Ltd | Education | 2017 |
| Dataswyft Ltd | Information & communication | 2015 |
| Dataswyft Network Ltd | Information & communication | 2023 |
| Dave Collinge Consulting Limited | Professional & scientific | 2020 |
| Davey Consulting Limited | Information & communication | 2003 |
| David Brothers Cars Ltd | Wholesale & retail | 2016 |
| David Dodds Transport Ltd | Transport & logistics | 2008 |
| David Hart Ltd | Information & communication | 2022 |
| Dawson Garwood Limited | Professional & scientific | 2010 |
| Day JOB Music Ltd | Arts & recreation | 2025 |
| DB Roofing & Cladding Ltd | Construction | 2012 |
| DB Sports Marketing Ltd | Professional & scientific | 2025 |
| DC Carpets Limited | Wholesale & retail | 2011 |
| DC Vibe Ltd | Professional & scientific | 2025 |
| DE Courcy Electrical Ltd | Extraterritorial | 2024 |
| Dean Reilly Design Ltd | Professional & scientific | 2022 |
| Dean Saunders Performance Golf Ltd | Education | 2021 |
| Dearman Electrical Limited | Construction | 2018 |
| Deborah Martin Accountant Ltd | Professional & scientific | 2019 |
| Decus Engineering Limited | Professional & scientific | 2017 |
| Deeplake Group Limited | Financial services | 2018 |
| DEF Rags Limited | Wholesale & retail | 2024 |
| Deluxe Perfect Cleaning Limited | Administrative & support | 2018 |
| Dementia Compass Limited | Education | 2021 |
| Demichi Limited | Manufacturing | 2017 |
| Denaire Motion Picture Poetry Ltd | Information & communication | 2022 |
| Denaire Motion Pictures Limited | Information & communication | 2022 |
| DER Merwe Properties Ltd | Real estate | 2020 |
| Derelict Limited | Professional & scientific | 2008 |
| Derlon Services Limited | Professional & scientific | 2016 |
| Dermabod Clinic Ltd | Other services | 2025 |
| Design & Build Consultancy Ltd | Professional & scientific | 2015 |
| Design With TEE Limited | Professional & scientific | 2025 |
| Dessaline Lodge Limited | Households | 2023 |
| DEV Mojo Limited | Information & communication | 2014 |