| Clynes Farms Ltd | Manufacturing | 2017 |
| Clynes Properties Limited | Real estate | 2026 |
| CM Investments London Limited | Real estate | 2020 |
| CM Watches Ltd | Manufacturing | 2026 |
| CN Mini Mart Ltd | Wholesale & retail | 2024 |
| CN Property Management Limited | Real estate | 2026 |
| CND Tutors U.K Ltd | Education | 2025 |
| CNR Security Ltd | Administrative & support | 2017 |
| Coach Hire Link Limited | Transport & logistics | 2015 |
| Coaching Cricket Excellence Ltd | Education | 2019 |
| Coastal Global Trade Ltd | Hospitality | 2018 |
| Cochilli Foods Ltd | Hospitality | 2024 |
| Cochilli Pro Ltd | Manufacturing | 2026 |
| Cockfosters News & Wine Ltd | Wholesale & retail | 2024 |
| Coco Unisex Hair Salon Limited | Other services | 2017 |
| Cognisant Accountancy Services Ltd | Professional & scientific | 2024 |
| Cognofin Limited | Professional & scientific | 2024 |
| Colie Ltd | Extraterritorial | 2020 |
| Colin Peters Ltd | Construction | 2021 |
| Collabsphere Limited | Information & communication | 2025 |
| Collins HR Consulting Ltd. | Professional & scientific | 2015 |
| Collis-Mills Property Limited | Real estate | 2024 |
| Colm Shorten Limited | Professional & scientific | 2020 |
| Colnbrook Court Ltd | Real estate | 2025 |
| Colnbrook Investment Ltd | Real estate | 2018 |
| Colnightd Ltd | Information & communication | 2025 |
| Coloured Stones Investments Ltd | Real estate | 2026 |
| Colston Bath and Spa Private Limited | Manufacturing | 2015 |
| Comap A.S. Ltd | Wholesale & retail | 2024 |
| Comfort Homes Housing Ltd | Real estate | 2025 |
| Comfortable Care Services Ltd | Health & social care | 2025 |
| Comfy Textiles UK Ltd | Wholesale & retail | 2026 |
| Commercial & Property Services Ltd | Construction | 2024 |
| Commercial and Industrial Supplies Limited | Wholesale & retail | 2019 |
| Commercial Excellence Consulting Ltd | Professional & scientific | 2025 |
| Common London Ltd | Arts & recreation | 2026 |
| Commune Hive Ltd | Real estate | 2024 |
| Commune Studios Ltd | Information & communication | 2024 |
| Community Multi-Services | Administrative & support | 2006 |
| Compare 4 Parking Limited | Wholesale & retail | 2025 |
| Compare Airport Deals Limited | Wholesale & retail | 2025 |
| Compare Parkings Ltd | Administrative & support | 2026 |
| Compton Cars Ltd | Administrative & support | 2018 |
| Compura Limited | Information & communication | 2015 |
| Concise Design and Build Ltd | Construction | 2021 |
| Confinity Solutions Ltd | Information & communication | 2018 |
| Connect Maan Builders Ltd | Construction | 2023 |
| Connect Repair Ltd | Wholesale & retail | 2026 |
| Connected Nature Ltd | Administrative & support | 2024 |
| Conrad Darare Ltd | Manufacturing | 2022 |
| Constance Care Support Ltd | Health & social care | 2023 |
| Constantin Construction Ltd | Construction | 2022 |
| Constantine House (Hayes) RTM Company Limited | Households | 2025 |
| Construction Hire Ltd | Construction | 2024 |
| Construction Huse and Apartament Ltd | Construction | 2025 |
| Construction Infinity Ltd | Construction | 2023 |
| Construction Services Management Limited | Construction | 2013 |
| Constructwise Developments Limited | Real estate | 2017 |
| Consult and Supply Limited | Administrative & support | 2008 |
| Consult Awais Ltd | Professional & scientific | 2023 |
| Consultaq Ltd | Professional & scientific | 2022 |
| Consulting World Wide Ltd. | Information & communication | 1998 |
| Contagious Creative Ltd | Professional & scientific | 2021 |
| Continental Audio Visual Ltd | Construction | 2017 |
| Continental Autos Group Ltd | Wholesale & retail | 2020 |
| Continental Freight Services Ltd | Transport & logistics | 2025 |
| Continental Property Resources Limited | Real estate | 2016 |
| Converting London Limited | Construction | 2019 |
| Conway Plastic Ltd | Construction | 2025 |
| Conway Surveyors Limited | Real estate | 2020 |
| Conway Windows Co. (UK) Limited | Manufacturing | 2018 |
| Cool Dudes Construction Ltd | Construction | 2023 |
| Coolbear Limited | Manufacturing | 2024 |
| Cooling Control Ltd | Construction | 2020 |
| Coome Road Investments Ltd | Households | 2024 |
| Coppercast Pharmaceutical UK Ltd | Wholesale & retail | 2020 |
| Core Property Developments Limited | Construction | 2013 |
| Coreflex Solutions Limited | Information & communication | 2020 |
| Corevue Ltd | Construction | 2021 |
| Corey’S Marketing Outreach Ltd | Professional & scientific | 2026 |
| Corner Door 2 Door Limited | Hospitality | 2025 |
| Corner Food & Wine Ltd | Wholesale & retail | 2026 |
| Cospat Consulting Limited | Professional & scientific | 2008 |
| Cost Cutter (Kingshill) Ltd | Wholesale & retail | 2010 |
| Costas Whole Sale Ltd | Wholesale & retail | 2025 |
| Costy Trans Limited | Transport & logistics | 2014 |
| Cotton Castle Limited | Wholesale & retail | 2020 |
| County Soft Limited | Hospitality | 2017 |
| County Special Limited | Information & communication | 2018 |
| Courier UK Express Ltd | Transport & logistics | 2025 |
| Coutts Holdings Limited | Real estate | 2017 |
| Coventry Store Ltd | Wholesale & retail | 2025 |
| Cowan Plant Ltd | Administrative & support | 2004 |
| Cowley Mill Road Ltd | Real estate | 2025 |
| Cozdel Ltd | Professional & scientific | 2016 |
| CPM Engineering Services Limited | Construction | 2016 |
| CPM Investments (London) Limited | Real estate | 2021 |
| CPM Trading AS Jolly's Ltd | Hospitality | 2021 |
| Cpost International Ltd | Transport & logistics | 2014 |
| CR Line Limited | Transport & logistics | 2025 |