| Cat and Cauldron Pubs Ltd | Hospitality | 2021 |
| Cat Lands Property Ltd | Real estate | 2019 |
| Cat Management (Shoreham) Company Limited | Real estate | 1991 |
| Cat Trumpet Music Limited | Arts & recreation | 2017 |
| Cat Wholesale Limited | Wholesale & retail | 2020 |
| Catalyst Commerce Limited | Professional & scientific | 2023 |
| Catalyst Corporation Ltd | Professional & scientific | 2019 |
| Catalyst IT Europe Limited | Information & communication | 2008 |
| Catalyst Ridge Ltd | Professional & scientific | 2024 |
| Catania Limited | Hospitality | 2017 |
| Catering Express Ltd | Hospitality | 2025 |
| Catering Repairs Limited | Manufacturing | 2026 |
| Caterpillar Red Limited | Wholesale & retail | 2014 |
| Catersol Limited | Hospitality | 2019 |
| Cathedral Yard Limited | Construction | 2015 |
| Catiran Co Ltd | | 1985 |
| Caton & Partners Limited | Professional & scientific | 2003 |
| Catpro Limited | Administrative & support | 2016 |
| CATS3000 Limited | Administrative & support | 2000 |
| Catstream (UK) Training Limited | Education | 2016 |
| Catstream Drivers Disability Awareness Training Limited | Education | 2016 |
| Cavendish Investments SDR Ltd | Arts & recreation | 2020 |
| Caxton Financial Limited | Transport & logistics | 2015 |
| Caxton Lands and Developments Limited | Real estate | 1960 |
| Caye UK Limited | Wholesale & retail | 2023 |
| CB Management Services Ltd | Administrative & support | 2025 |
| CB Perpetual Ltd | Real estate | 2026 |
| CBA Cleaning Services Limited | Administrative & support | 2025 |
| CBS Maintain Ltd | Construction | 2025 |
| CBW Staffing Executive Solutions Limited | Administrative & support | 2024 |
| CBW Staffing Permanent Solutions Limited | Administrative & support | 2024 |
| CBW Staffing Temporary Solutions Limited | Administrative & support | 2024 |
| CC ACC Software Limited | Financial services | 2023 |
| CC Advisory Limited | Professional & scientific | 2018 |
| CC Equine Ltd | Agriculture & fishing | 2025 |
| CC2 GP (English) LLP | | 2022 |
| CC5 Holdco Limited | Financial services | 2022 |
| CCA Events LLP | | 2021 |
| Ccdance Studios Ltd | Arts & recreation | 2025 |
| Cchb Ltd | Information & communication | 2024 |
| CCI Business Services Limited | Professional & scientific | 2009 |
| CCI Corporate Services Limited | Professional & scientific | 2022 |
| CCL Building Supplies Ltd | Wholesale & retail | 2026 |
| CCR Drylining Limited | Construction | 2018 |
| CCR Property Southern Limited | Real estate | 2021 |
| CCS Holdings Ltd | Construction | 2015 |
| Cctv Brighton Limited | Extraterritorial | 2014 |
| Cctv Security & Electrical Ltd | Construction | 2023 |
| CDC Creative Ltd | Information & communication | 2022 |
| CDH Holdings Limited | Financial services | 2025 |
| CDH Trading Ltd | Professional & scientific | 2025 |
| Cdjr&P LLP | | 2013 |
| CDO Investments Limited | Real estate | 2026 |
| Cdsb Limited | Real estate | 2020 |
| CDT Finishers Brighton Limited | Construction | 2024 |
| CEA Events Limited | Administrative & support | 2024 |
| Cearmed Leaf Ltd | Wholesale & retail | 2023 |
| CEB Mortgages Limited | Financial services | 2015 |
| Cecoss UK Ltd | Financial services | 2014 |
| Cedars Assist Limited | Transport & logistics | 2011 |
| Cedarsoftware Limited | Information & communication | 2023 |
| Cedarwood N.A-R Ltd | Construction | 2014 |
| Cedarwood Residential Care Ltd | Financial services | 2011 |
| Cedp Chinese Centre Ltd | Education | 2002 |
| Cedric Management Limited | Other services | 1982 |
| CEE CEE Private Limited | Health & social care | 2013 |
| CEL Sheet Metal Limited | Manufacturing | 2006 |
| Cell Prosper Ltd | Professional & scientific | 2025 |
| Cell Software Services Limited | Information & communication | 2012 |
| Cellar Partners Ltd | Extraterritorial | 2025 |
| Cellars of Italy 2015 Ltd | Administrative & support | 2011 |
| Celltech Fixit Limited | Wholesale & retail | 2024 |
| Celtoys Ltd | Information & communication | 2013 |
| Celty Limited | Financial services | 2026 |
| Centenary House Ltd | Households | 2011 |
| Centennial Park Phase 400 Limited | Construction | 2005 |
| Central Appliances Brighton Limited | Wholesale & retail | 2015 |
| Central Maintenance London Ltd | Real estate | 2012 |
| Central Telephone and Telegraph Limited | | 1985 |
| Centralchance Property Management Limited | Households | 1992 |
| Centraleyes Systems Limited | Information & communication | 2019 |
| Centre for Africa Cultural Diplomacy (Cacd) Ltd | Professional & scientific | 2025 |
| Centre for Ethical Healthcare Ltd | Professional & scientific | 2012 |
| Centre for Policy Development and Advocacy Limited | Other services | 2013 |
| Centre Square Commercial Limited | Real estate | 2020 |
| Centre Stage Security Ltd | Administrative & support | 2025 |
| Centric 8 Ltd | Administrative & support | 2023 |
| Centrix Consult Ltd | Professional & scientific | 2022 |
| Centroidpm Ltd | Professional & scientific | 2021 |
| Centurion (Northeast) Limited | Construction | 2023 |
| Centurion City Capital Limited | Real estate | 1972 |
| Centurion Construction Ltd | Administrative & support | 2011 |
| Centurion Developments Limited | Real estate | 1990 |
| Century 18 Limited | Wholesale & retail | 2019 |
| Cerelux UK Ltd | Wholesale & retail | 2018 |
| Certified Heating Limited | Construction | 2023 |
| Certified Roofing and Guttering Ltd | Construction | 2025 |
| Cerulean Lane Ltd | Wholesale & retail | 2026 |
| Ceyda Tanc Dance CIC | Arts & recreation | 2023 |
| CFA Hair Vault Ltd | Other services | 2026 |