| Crest International Consultants Limited | Professional & scientific | 2023 |
| Crestlake Investments Limited | Financial services | 2016 |
| Cribb Media Ltd | Information & communication | 2024 |
| Crizmo Productions Ltd | Information & communication | 2025 |
| CRL Couriers Ltd | Transport & logistics | 2022 |
| Cronin's Cleaning Services Limited | Administrative & support | 2016 |
| Cross Channel Classics Limited | Wholesale & retail | 2017 |
| Crossland Structural Limited | Professional & scientific | 2024 |
| Crossley Consult EOT Ltd | Financial services | 2025 |
| Crossley Consult Ltd | Professional & scientific | 2014 |
| Crossways Healthcare Limited | Health & social care | 2002 |
| Crown Hill Surrey Developments Limited | Construction | 2016 |
| Crown Infrastructure Services Ltd | Information & communication | 2023 |
| Crown Street CUT Ltd | Other services | 2026 |
| Crowther & Co Surveyors Limited | Administrative & support | 2005 |
| CRU Leader Development Ltd | Administrative & support | 2017 |
| Crucial Design & Build Limited | Extraterritorial | 2015 |
| Crucial Environmental Limited | Water & waste | 2012 |
| Crucial Laboratories Limited | Professional & scientific | 2019 |
| Crunch Properties Limited | Real estate | 2025 |
| Cryarn Blake Limited | Professional & scientific | 2018 |
| Crystal Earth Ltd | Wholesale & retail | 2018 |
| CS Inc. Ltd | Real estate | 2021 |
| Csardas Limited | Professional & scientific | 2016 |
| CSB Construction Services Ltd | Construction | 2019 |
| CSB Custom Solutions Ltd | Construction | 2025 |
| CSL Europe Limited | Transport & logistics | 2011 |
| CT Eco Plus Limited | Construction | 2014 |
| CT Fabrications Limited | Manufacturing | 2024 |
| CT Maintain Ltd | Construction | 2019 |
| CTC Ferrovie Ltd | Transport & logistics | 2005 |
| Cthulhu Ltd | Arts & recreation | 2022 |
| CTW Financial Services Ltd | Financial services | 2007 |
| Cube Controls Limited | Construction | 2008 |
| CUBE2 Limited | Construction | 2014 |
| Cucinetta Ltd | Hospitality | 2021 |
| Cuff Miller & Co.Limited | Real estate | 1947 |
| Cuff Miller and Company (Littlehampton) Limited | Wholesale & retail | 1947 |
| Cuisine Enterprises Limited | Hospitality | 2004 |
| Cuisinier Management Limited | Real estate | 2021 |
| Cuisinier Properties Limited | Real estate | 2017 |
| Cullingford Meats Limited | Wholesale & retail | 2021 |
| Cult Colours Ltd | Construction | 2025 |
| Cumberland House Consulting Ltd | Information & communication | 2018 |
| Cumulus Distribution Limited | Information & communication | 1994 |
| Cupdanor Limited | | 1987 |
| Curae Management Services Ltd | Professional & scientific | 2020 |
| Curry House Angmering Limited | Hospitality | 2018 |
| Curtain Corner (Worthing) Ltd | Manufacturing | 2008 |
| Curtis Tilbury Holdings Ltd. | Information & communication | 2017 |
| CUT Above Carpentry & Construction Limited | Manufacturing | 2014 |
| CUT MIX Media Limited | Information & communication | 2023 |
| CUT to the Beat Ltd. | Information & communication | 2002 |
| Cutover Limited | Extraterritorial | 2015 |
| CVB Consulting Limited | Professional & scientific | 2026 |
| CW Invest Ltd | Professional & scientific | 2025 |
| CWC Technical Services Ltd | Professional & scientific | 2009 |
| Cwrwgl Games Limited | Information & communication | 2024 |
| CX Accountants Ltd | Professional & scientific | 2013 |
| Cybersecurity Services Ltd | Information & communication | 2015 |
| Cyclevox Commentary Limited | Information & communication | 2017 |
| Cyclevox Limited | Information & communication | 2007 |
| Cygar LLP | | 2022 |
| Cygar Properties Ltd | Real estate | 2025 |
| CYM Limited | Health & social care | 2020 |
| Cyoza Ltd | Wholesale & retail | 2025 |
| D & a Consultancy Partnership Limited | Agriculture & fishing | 2022 |
| D & E Group Ltd | Other services | 2018 |
| D & N Godfrey Services Limited | Hospitality | 2004 |
| D and C Bloodstock LLP | | 2008 |
| D B Coachworks Limited | Wholesale & retail | 2013 |
| D Build Refurbishments Holdings Limited | Financial services | 2023 |
| D C Heating Solutions Ltd | Construction | 2017 |
| D C Renovations Sussex Ltd | Construction | 2024 |
| D C Stevens Ltd | Construction | 2015 |
| D G Bull Glass Services Limited | Manufacturing | 2012 |
| D Green Consultants Limited | Information & communication | 2010 |
| D J Recycling Ltd | Water & waste | 2022 |
| D J Roofing Contractors Limited | Construction | 2002 |
| D P Fire Engineering Ltd | Construction | 2018 |
| D Pollard Limited | Construction | 2008 |
| D R Freehold Ltd | Real estate | 2024 |
| D S Macleod Holdings Ltd | Real estate | 2024 |
| D Sear Limited | Professional & scientific | 2014 |
| D Towers Electrical Ltd | Construction | 2011 |
| D&Bu Construction Ltd | Construction | 2024 |
| D&D Car Trade Ltd | Wholesale & retail | 2018 |
| D&D Oriental Foods Import Export International Services Ltd | Wholesale & retail | 2020 |
| D&D Smile Limited | Health & social care | 2014 |
| D&E Group Properties Ltd | Real estate | 2021 |
| D&K Office Ltd | Wholesale & retail | 2019 |
| D&M Audiovisual Ltd | Wholesale & retail | 1964 |
| D&O Management Services Ltd | Construction | 2007 |
| D. Cells Holdings Limited | Financial services | 2020 |
| D2B Solutions Limited | Professional & scientific | 2012 |
| DAB Jewellers Ltd | Manufacturing | 2018 |
| Dacre Developments (Sussex) Ltd | Construction | 2009 |
| DAD LA Soul C.I.C. | Arts & recreation | 2017 |
| Dadiator Ltd | Wholesale & retail | 2023 |
| Daft Tech Limited | Information & communication | 2022 |