| Crockford Court Management Ltd | Households | 2012 |
| Crosslink Healthcare Limited | Administrative & support | 2024 |
| Crossway Insulation Ltd | Construction | 2010 |
| Crossway Plumbing & Heating Limited | Construction | 2003 |
| Crown Construction Southern Ltd | Construction | 2024 |
| Crown Software Solutions Limited | Information & communication | 2016 |
| Crown's Rock Fish & Chips Limited | Hospitality | 2024 |
| Crownfila Limited | Administrative & support | 2021 |
| Crownscape Ltd | Real estate | 2024 |
| CRS Roofing Contractors Ltd | Construction | 2026 |
| Cruise Hotels Ltd | Hospitality | 2020 |
| Crust & Grill Ltd | Hospitality | 2025 |
| Cryptorecon Limited | Education | 2021 |
| Crystal Star (UK) Limited | Hospitality | 2013 |
| CS Civils and Drainage Ltd | Construction | 2023 |
| CS Ground Care Ltd | Administrative & support | 2026 |
| CSF Trans Ltd | Transport & logistics | 2017 |
| CSL Electrical (Southern) Ltd | Construction | 2015 |
| Cspl Investments Limited | Real estate | 2024 |
| CT Management Holdings Ltd | Financial services | 2019 |
| CTB 05 Limited | Financial services | 2021 |
| CTG Decoration Ltd | Construction | 2026 |
| CTS Europe Limited | Manufacturing | 2010 |
| CTT Developments Limited | Construction | 2022 |
| CU Medical Services Limited | Manufacturing | 2021 |
| Cube Management Solutions Limited | Professional & scientific | 2009 |
| Cumberland Business Centre Management Limited | Administrative & support | 1989 |
| Cummins Construction Southern Ltd | Construction | 2012 |
| CUP and Go Ltd | Wholesale & retail | 2019 |
| Curated by Crofts Ltd | Wholesale & retail | 2026 |
| Curium Pharma UK Ltd. | Wholesale & retail | 2014 |
| Curnow Carpentry Limited | Manufacturing | 2025 |
| Currie Property Holdings Ltd | Real estate | 2024 |
| Curtis Plumstone Limited | Professional & scientific | 2013 |
| Curtis Williams Ltd | Professional & scientific | 2010 |
| Curve Property Limited | Real estate | 2024 |
| Curvy Dolls Ltd | Other services | 2024 |
| Custodes Estates Ltd | Real estate | 2025 |
| Custom Bike Works Ltd. | Professional & scientific | 2011 |
| Custom Management Limited | Other services | 1997 |
| Custom Metal Polishers Limited | Administrative & support | 2008 |
| Custom Pools & Developments Limited | Construction | 2019 |
| Customisedbuilders Ltd | Construction | 2024 |
| Cutis Limited | Health & social care | 2024 |
| Cuttill Enterprises Ltd | Real estate | 2017 |
| CV Geeks Ltd | Administrative & support | 2025 |
| CVB Bespoke Furniture & Repairs Limited | Extraterritorial | 2020 |
| CVH Freelance Ltd | Construction | 2024 |
| Cvsr Ltd | Wholesale & retail | 2024 |
| CW Auto Consulting Limited | Wholesale & retail | 2018 |
| CWB Consulting Co. Ltd | Professional & scientific | 2025 |
| CWK Properties Limited | Real estate | 1993 |
| Cybaverse Ltd | Information & communication | 2018 |
| Cyber Defen Guard UK Ltd | Administrative & support | 2025 |
| Cycle Trace Ltd | Wholesale & retail | 2023 |
| Cycles Trace Ltd | Wholesale & retail | 2025 |
| Cyclops Marine Ltd | Professional & scientific | 2018 |
| Czcateringltd Ltd | Hospitality | 2026 |
| D & E Tilbury Holdings Limited | Financial services | 2024 |
| D & E Tilbury Properties Limited | Real estate | 2024 |
| D & H Events Group Ltd | Arts & recreation | 2024 |
| D & J Roofing Limited | Construction | 2022 |
| D & L Builders Ltd | Construction | 2017 |
| D & L Care Solution Ltd | Health & social care | 2019 |
| D & L Plant Hire Ltd | Administrative & support | 2006 |
| D & N Doyle Brickwork Ltd | Construction | 2015 |
| D & S Properties (Portsmouth) Limited | Real estate | 2021 |
| D & T Bathrooms Ltd | Construction | 2014 |
| D & T Leisure Limited | Hospitality | 2021 |
| D a DRY Lining Limited | Construction | 2010 |
| D and J Bardell Holdings Ltd | Real estate | 2022 |
| D and L Brickwork Ltd | Construction | 2021 |
| D and L Southern Ltd | Construction | 2018 |
| D Bell Facilities Ltd | Administrative & support | 2026 |
| D C Groundworks Limited | Construction | 2013 |
| D C Roofing & Sons Ltd | Construction | 2014 |
| D Eyre Brickwork Ltd | Construction | 2016 |
| D Gates Specialist Treatments Limited | Construction | 2009 |
| D H Recycling Limited | Administrative & support | 2016 |
| D Hardy Holdings Limited | Financial services | 2022 |
| D Jako Ltd | Transport & logistics | 2015 |
| D M Building & Restoration Ltd | Construction | 2012 |
| D N Asphalt Services Limited | Construction | 2010 |
| D N Associates Limited | Construction | 2000 |
| D Norkett Decorators Ltd | Construction | 2006 |
| D P Auto Repairs Limited | Wholesale & retail | 2011 |
| D P Services & Maintenance Limited | Administrative & support | 2004 |
| D Parker Engineering Limited | Professional & scientific | 2016 |
| D Squared Electrical Services Ltd | Construction | 2013 |
| D Sullivan Metals Limited | Wholesale & retail | 2011 |
| D Taylor's Plumbing & Heating Ltd | Construction | 2023 |
| D&C Amusements Ltd | Arts & recreation | 2026 |
| D&D Landscapes and Groundworks Ltd | Administrative & support | 2018 |
| D&H Brickwork Ltd | Construction | 2023 |
| D&I Property Investments Limited | Real estate | 2017 |
| D&K Wholesale Ltd | Wholesale & retail | 2025 |
| D&S Carpentry Southern Ltd | Manufacturing | 2018 |
| D-Emes Investment Ltd | Wholesale & retail | 2020 |
| D-Luxe Fitouts Ltd | Construction | 2025 |
| D.A. Systems Limited | Information & communication | 1999 |