| Classic Express Limited | Administrative & support | 2022 |
| Clauss Mechanical Services Ltd | Other services | 2014 |
| Clean Cafe Ltd | Hospitality | 2026 |
| Clean Ceauticals Limited | Wholesale & retail | 2023 |
| Clean CUT Gardeners Ltd | Administrative & support | 2023 |
| Clear Lake Limited | Professional & scientific | 2024 |
| Clear Measures Limited | Professional & scientific | 2024 |
| Clementina Day Centre Community Interest Company | Health & social care | 2019 |
| Clinexpert Ltd | Professional & scientific | 2025 |
| Cloud Homes Limited | Real estate | 2020 |
| Cloudcoin Ltd | Wholesale & retail | 2020 |
| Cmhv Properties Ltd. | Real estate | 2021 |
| CNC Logistics Solution Ltd | Transport & logistics | 2025 |
| Coco Transport Ltd | Transport & logistics | 2026 |
| Code and Algorithms PVT Ltd | Information & communication | 2025 |
| Coffee & Cookies Ltd | Hospitality | 2024 |
| Cogniwise Ltd | Health & social care | 2022 |
| Cogstar Limited | Wholesale & retail | 2024 |
| Cohen Lettings Limited | Households | 2026 |
| Comechop Ltd | Information & communication | 2026 |
| Comfy-Heat Limited | Construction | 2023 |
| Community First Foundation | Education | 2011 |
| Complete Landlords Solutions Ltd | Construction | 2020 |
| Conected Ltd | Health & social care | 2025 |
| Confort Construction Ltd | Construction | 2018 |
| Conifer Properties Ltd | Households | 2025 |
| Construct With MJ Ltd | Construction | 2026 |
| Construction and Renovation Services London Ltd | Construction | 2015 |
| Construction M.S.A Ltd | Construction | 2022 |
| Consulting LK Ltd | Information & communication | 2024 |
| Convifuels Limited | Wholesale & retail | 2023 |
| Convoy Town Park Limited | Real estate | 2021 |
| Cool Service Group Engineers Limited | Manufacturing | 2019 |
| Corduba Estates Ltd | Real estate | 2022 |
| Corefocus Group Ltd | Professional & scientific | 2024 |
| Coregen Business Solution Ltd | Wholesale & retail | 2017 |
| Coro Europe Limited | Mining & quarrying | 2006 |
| Cortana Echo Ltd | Health & social care | 2013 |
| COS Building Limited | Construction | 2020 |
| Costa Civil Engineering Ltd | Construction | 2013 |
| Courier Sped Ltd | Transport & logistics | 2019 |
| Cove Venture Ltd | Information & communication | 2007 |
| Coventry Blinds & Shutters Ltd | Manufacturing | 2026 |
| Cover Network UK Limited | Mining & quarrying | 2004 |
| Cozma Cipria-Petru 30908 Limited | Transport & logistics | 2014 |
| CP Technologies Limited | Information & communication | 2012 |
| Cpap UK Store Limited | Wholesale & retail | 2023 |
| CRAFTEDWITHJOY2025 Ltd | Manufacturing | 2025 |
| Crafties Ltd | Wholesale & retail | 2026 |
| Crazy COW Ltd | Transport & logistics | 2019 |
| CRE8 Digital Studio Ltd | Wholesale & retail | 2026 |
| CRI on Ltd | Wholesale & retail | 2025 |
| Crispy Cutz Limited | Other services | 2025 |
| Crownlane Autos Ltd | Wholesale & retail | 2026 |
| Crystal Dust Limited | Administrative & support | 2020 |
| Crystal Kitchen & Bedrooms Ltd | Construction | 2020 |
| Crystal Kitchen Ltd | Construction | 2021 |
| Crystal Optics Limited | Health & social care | 2022 |
| CSA Retail Ltd | Wholesale & retail | 2024 |
| CSM & Amro Ltd | Transport & logistics | 2023 |
| CSN Plumbing Specialist Ltd | Construction | 2025 |
| CT International Design Studio Limited | Professional & scientific | 2025 |
| Ctdw Limited | Professional & scientific | 1992 |
| Cubasca Limited | Wholesale & retail | 2021 |
| Cukaj Homes Ltd | Construction | 2019 |
| Culture Landscapes Ltd. | Administrative & support | 2018 |
| Cumex Ltd | Administrative & support | 2025 |
| Cure Artificial Intelligence Ltd | Information & communication | 2024 |
| Curelariu Construction Limited | Construction | 2017 |
| Curry Leaves Express Ltd | Hospitality | 2025 |
| CWP & CWP Consulting Limited | Information & communication | 2022 |
| D & C Management Services Ltd | Real estate | 2014 |
| D & D Cleaning Solutions Ltd | Administrative & support | 2026 |
| D & M Hair N Beauty Limited | Other services | 2023 |
| D H Builders & Contractors Ltd | Construction | 2024 |
| D Route Logistics Ltd | Transport & logistics | 2019 |
| D W GBS Ltd | Construction | 2019 |
| D Wray Consulting Limited | Professional & scientific | 2013 |
| D&A Bricklaying Ltd | Construction | 2022 |
| D&C Logistics Ltd | Professional & scientific | 2022 |
| D&R Deals Europe Ltd | Wholesale & retail | 2023 |
| D&R E.Com Store Ltd | Wholesale & retail | 2025 |
| D&S Electrics Ltd | Construction | 2026 |
| D-Core Construction Ltd | Construction | 2025 |
| D.B. Smart Hand Car Wash Ltd | Other services | 2015 |
| D.W.V.London-Installation Ltd | Construction | 2016 |
| DA Builders Ltd | Construction | 2023 |
| Daaproperty Ltd | Households | 2020 |
| Dabdhere Property Ltd | Real estate | 2022 |
| Dailyneeds Solution Ltd | Wholesale & retail | 2024 |
| Daisy’S Cosy Bakehouse Ltd | Manufacturing | 2026 |
| Dalloll Technology Limited | Information & communication | 2011 |
| Dalwinder Sangha Limited | Transport & logistics | 2021 |
| DAN Building Projects Ltd | Construction | 2026 |
| Dandelion Care Services Limited | Health & social care | 2025 |
| Danhub Ltd | Construction | 2017 |
| Daniel Netto Limited | Wholesale & retail | 1997 |
| Danimart Ltd | Transport & logistics | 2019 |
| Danlea Construction Ltd | Construction | 2021 |
| Dardani Ltd | Construction | 2026 |