| CK Plumbing & Tiling Ltd | Construction | 2024 |
| CL Kitchens Limited | Construction | 2023 |
| Claims Services & Inspection Limited | Professional & scientific | 2012 |
| Clar-Ity IT Consultancy Ltd | Information & communication | 2015 |
| Clear Path Licensing Solutions Limited | Professional & scientific | 2026 |
| Clifton Shout Ltd | Information & communication | 2006 |
| Clinlogis Group Ltd | Professional & scientific | 2025 |
| Clinlogis Ltd | Professional & scientific | 2019 |
| Clinstats Limited | Professional & scientific | 2014 |
| CM Gone Pest Control Ltd | Administrative & support | 2017 |
| CMC & Associates Ltd | Professional & scientific | 2025 |
| CNN Property Holdings Ltd | Real estate | 2017 |
| Coach and Horses Limited | Hospitality | 2012 |
| COB Eire Ltd | Health & social care | 2026 |
| Cognition Health Communications Limited | Professional & scientific | 2018 |
| Colliderscope Ltd | Information & communication | 2022 |
| Collins Systems Services Limited | Manufacturing | 2016 |
| Columbus Cabinets Ltd | Administrative & support | 2012 |
| Compass and Spectre Limited | Administrative & support | 2017 |
| Compassionate D Limited | Health & social care | 2022 |
| Competition Golf Limited | Information & communication | 2024 |
| Connections House Limited | Real estate | 2021 |
| Construct Your Future Limited | Education | 2025 |
| Constructive Building Solutions Ltd | Professional & scientific | 2024 |
| Contractiq Limited | Professional & scientific | 2018 |
| Control Engineering Technology Limited | Manufacturing | 1994 |
| Copper House Cables Ltd | Manufacturing | 2019 |
| Core Technology Ltd | Information & communication | 2025 |
| Corrie Consultancy Ltd | Administrative & support | 2017 |
| Cosa MIA Limited | Other services | 2011 |
| Cottonpawscreatives Ltd | Arts & recreation | 2021 |
| Counselling and Therapy Limited | Health & social care | 2024 |
| Countrywide Hire Limited | Extraterritorial | 2010 |
| Courtyard Yoga Ltd | Other services | 2019 |
| CP (Bedford) Limited | Real estate | 2004 |
| Crack on Productions Limited | Information & communication | 2011 |
| Craddock Industries Limited | Wholesale & retail | 2026 |
| Craft Music Ltd | Arts & recreation | 2022 |
| Creation Invest Ltd | Real estate | 2021 |
| Creative Empirical Ltd | Professional & scientific | 2025 |
| Cremin Property Ltd | Construction | 2018 |
| Crestar Ltd | Wholesale & retail | 2005 |
| Crospay Limited | Transport & logistics | 2020 |
| Crown Barbers Langford Ltd | Other services | 2023 |
| Cryptoscope Films Limited | Information & communication | 2017 |
| Crystal Asset Holdings Limited | Real estate | 2016 |
| CSM Relaxa PVT Limited | Real estate | 2025 |
| Curious Learning Ltd | Professional & scientific | 2003 |
| Custom Electronics Holdings Limited | Information & communication | 2001 |
| Custom Probate Services Ltd | Professional & scientific | 2015 |
| Custom Wills Ltd | Professional & scientific | 2010 |
| Cutsman Barbers Ltd | Other services | 2025 |
| D & G Limited | Other services | 1995 |
| D & S Precision Coatings Limited | Manufacturing | 2003 |
| D Brown Properties Ltd | Real estate | 2018 |
| D C Vehicle Repairs Ltd | Wholesale & retail | 2011 |
| D Firth Transport Ltd | Transport & logistics | 2019 |
| D M Specialist Ltd | Manufacturing | 1997 |
| D&F Centre Ltd | Wholesale & retail | 2019 |
| D&H Grill Ltd | Hospitality | 2026 |
| D&S Collective Limited | Financial services | 2019 |
| D-Railed Dance Ltd | Arts & recreation | 2019 |
| D. M. Barnett Ltd | Information & communication | 2012 |
| DAH Corporation Limited | Professional & scientific | 2015 |
| DAL Flat Roofing Specialists Limited | Construction | 2013 |
| DAN VR Ltd | Information & communication | 2016 |
| Danacorp Holding Ltd | Financial services | 2020 |
| Daniel Beacock Photography Ltd | Professional & scientific | 2023 |
| Daswan Ventures Ltd | Real estate | 2024 |
| Data Salt Ltd | Information & communication | 2024 |
| David Clerihew Associates Limited | Professional & scientific | 2010 |
| David Croft Media Limited | Information & communication | 2010 |
| Davidescu Construction Ltd | Construction | 2026 |
| Dayspring Hub | Other services | 2016 |
| Dazlin Jewel Ltd | Wholesale & retail | 2025 |
| Dblg Ltd | Wholesale & retail | 2017 |
| Dbrl Management Solutions Limited | Professional & scientific | 2023 |
| Dcam Project Ltd | Construction | 2025 |
| DCS Property Maintenance UK Limited | Other services | 2017 |
| DCX1 Group Ltd | Professional & scientific | 2026 |
| DE Mornay Limited | Construction | 2003 |
| DE Silva Holdings Ltd | Real estate | 2022 |
| Dead Parrot Ltd | Information & communication | 2015 |
| Dee-Jay Properties Limited | Real estate | 2002 |
| Defitness Ltd | Health & social care | 2022 |
| Defreitas Limited | Arts & recreation | 2018 |
| Delta VIE Ltd | Professional & scientific | 2021 |
| Deniz Grill Ltd | Hospitality | 2025 |
| Depilex Smileagain Foundation (UK) | Health & social care | 2015 |
| Dermacode Clinic Ltd | Other services | 2025 |
| Destina Properties Ltd | Real estate | 2020 |
| Devane Construction Ltd | Other services | 2026 |
| Devmattic Ltd. | Information & communication | 2017 |
| Devserve Ltd | Information & communication | 2025 |
| DGM Customs Ltd | Manufacturing | 2024 |
| DH Ashley Investments Limited | Other services | 2018 |
| DH Ashley Property Services Limited | Other services | 2024 |
| DHA Food Limited | Hospitality | 2025 |
| DHJ Ventures Ltd | Information & communication | 2018 |
| Dial Data Solutions Limited | Wholesale & retail | 2004 |