| CRM Consulting Limited | Professional & scientific | 2025 |
| Croc Demo Ltd | Construction | 2019 |
| Cromer Dental LAB Limited | Health & social care | 2019 |
| Cromer House Dental Practice Limited | Health & social care | 2014 |
| Cross Deep Dental Limited | Health & social care | 2014 |
| Crossfit Bicester Ltd | Arts & recreation | 2017 |
| Crown and Sparkles Cleaning Services Ltd | Administrative & support | 2025 |
| Crown Services(Uk) Ltd | Other services | 2023 |
| CRP Home Solutions Ltd | Real estate | 2021 |
| Crsi Limited | Professional & scientific | 2011 |
| Crway Limited | Transport & logistics | 2025 |
| Crystal Clear Media Ltd | Real estate | 2006 |
| Crystal Electrics Ltd | Construction | 2021 |
| CS Fencing & Gardening Contractors UK Ltd | Administrative & support | 2024 |
| CS Properties Lettings Ltd | Real estate | 2010 |
| CS Sport and Remedial Massage Therapy Ltd | Health & social care | 2025 |
| CTS (Solent) Limited | Wholesale & retail | 2026 |
| Culture & Culture Limited | Hospitality | 2013 |
| Cumberland Electrochemical Limited | Administrative & support | 1949 |
| Cunco Ltd | Construction | 2016 |
| Cunha Construction Ltd | Construction | 2023 |
| Curated Performance Ltd | Wholesale & retail | 2024 |
| Curry Nights With Nandita Ltd | Hospitality | 2021 |
| Curtis & Carder Services Limited | Construction | 2006 |
| Curtis & Carder Services Maintenance Ltd | Construction | 2013 |
| Curtis & Carder Services Supplies Ltd | Construction | 2013 |
| Curtis Bros Ltd | Real estate | 2020 |
| Custom Construction Services Oxon Limited | Construction | 2013 |
| CW Props Limited | Arts & recreation | 2008 |
| CWD Architects Ltd | Professional & scientific | 2008 |
| CWL Solutions Ltd | Administrative & support | 2024 |
| CX Adventure Ltd | Education | 2025 |
| CX Kueppers Limited | Financial services | 2018 |
| CX Property Investments Ltd | Real estate | 2023 |
| CX Property Ltd | Real estate | 2023 |
| Cyber Ninjas Corp Ltd | Information & communication | 2024 |
| Cyber Resilience Limited | Information & communication | 2019 |
| Cyberpulze Limited | Information & communication | 2020 |
| Cyclopes Software Solutions Limited | Information & communication | 2024 |
| D & G Cleaning Services Limited | Administrative & support | 2024 |
| D & G Distribution Limited | Transport & logistics | 1993 |
| D & I Phillips Properties Limited | Real estate | 1970 |
| D & M Recycling & Waste Management Limited | Water & waste | 2002 |
| D a Clayton Warehousing Limited | Transport & logistics | 2012 |
| D and C Properties Limited | Real estate | 1973 |
| D and L Powell Limited | Health & social care | 2023 |
| D C Jeffs Limited | Extraterritorial | 2025 |
| D C Lawson Electrical Ltd | Construction | 2014 |
| D G Coops Services Ltd | Manufacturing | 2025 |
| D L Hancock Holdings Limited | Financial services | 2017 |
| D L. Hancock Limited | Other services | 2003 |
| D T Construction (Oxford) Limited | Construction | 2017 |
| D W Investors Ltd | Real estate | 2024 |
| D&A Construction Specialists Limited | Construction | 2024 |
| D'S Done Deal Ltd | Real estate | 2024 |
| D.J. Doors & Electrical Services Ltd | Construction | 2004 |
| D.Zine 4U Ltd | Professional & scientific | 2017 |
| DA68 Consulting Ltd | Information & communication | 2025 |
| Daac Consulting Limited | Education | 2024 |
| Dabool Property Services Ltd | Households | 2021 |
| Dabool Services Limited | Information & communication | 2010 |
| DAC Property Limited | Real estate | 2023 |
| Dacastello Limited | Wholesale & retail | 2013 |
| Daciline Ltd | Wholesale & retail | 2022 |
| Daisy Hudson Creative Limited | Information & communication | 2014 |
| Dajora Limited | Construction | 2024 |
| Dalcour Maclaren Limited | Professional & scientific | 2003 |
| Daley FX Ltd | Administrative & support | 2025 |
| Damira Commercial Properties Ltd | Other services | 2016 |
| Damira Dental Studios Limited | Health & social care | 2010 |
| Damira Group Holdings Limited | Health & social care | 2020 |
| Damira Holdings Limited | Health & social care | 2024 |
| Damira Properties Holdings Limited | Other services | 2020 |
| Damira Properties Limited | Other services | 2014 |
| Dan's Action Vehicles Limited | Arts & recreation | 2017 |
| Dance Creative | Arts & recreation | 2020 |
| Dandy Gallery Retro Vintage Interiors Limited | Wholesale & retail | 2025 |
| Danehill Interiors Limited | Construction | 2009 |
| Danucy Ltd | Professional & scientific | 2016 |
| Dan’S Group Holdings Limited | Financial services | 2025 |
| Dapper Investments Ltd | Real estate | 2021 |
| Darcica Logistics Limited | Transport & logistics | 2020 |
| Darivy Homes Limited | Construction | 2023 |
| Dark Side Beauty Ltd | Other services | 2023 |
| Dark Sorrow Ltd | Information & communication | 2021 |
| Darling Developments Limited | Real estate | 2021 |
| Darren Hutt Painting Ltd | Construction | 2025 |
| Dartin Property Ltd | Real estate | 2025 |
| Darwen Commercials Limited | Wholesale & retail | 2024 |
| Darwenside Limited | Health & social care | 2013 |
| DAS UK Developments Ltd | Real estate | 2024 |
| Dassed Legacy Limited | Health & social care | 2021 |
| Data Efficiency Limited | Information & communication | 2009 |
| Dave Griffin Glass Specialist Limited | Wholesale & retail | 2011 |
| Dave OZZ Handyman Services Ltd | Other services | 2025 |
| Dave Upton Home Improvements Limited | Construction | 2005 |
| Davewoodz Ltd | Professional & scientific | 2014 |
| David Beecroft Limited | Construction | 1963 |
| David Cadwallader & Co Limited | Professional & scientific | 2014 |
| David Fullerton Ltd | Professional & scientific | 2023 |