| Convelii Cleaning Services Ltd | Administrative & support | 2022 |
| Conveyancing for YOU Ltd | Professional & scientific | 2023 |
| Conveyancing Panel Management Limited | Administrative & support | 2023 |
| Conveyguru Limited | Information & communication | 2020 |
| Cook Family Funerals Ltd | Other services | 2024 |
| Cook Start CIC | Education | 2023 |
| Cook's of Bedford Limited | Wholesale & retail | 1964 |
| Cook-Sutton Properties Limited | Real estate | 2023 |
| Cookbox Inc Ltd | Wholesale & retail | 2021 |
| Cooke Optics Limited | Manufacturing | 1998 |
| Cooke Strategy Limited | Professional & scientific | 2017 |
| Cooker Master Limited | Wholesale & retail | 2015 |
| Cookes Capital Ltd | Real estate | 2026 |
| Cookie Republic Ltd | Wholesale & retail | 2025 |
| Cookies and Sparkles Ltd | Wholesale & retail | 2018 |
| COOL2BTRANS Ltd | Professional & scientific | 2023 |
| Cooltech UK Limited | Construction | 2003 |
| Coopcomms Limited | Agriculture & fishing | 2025 |
| Cooper 4 Wealth Management Limited | Professional & scientific | 2022 |
| Cooper Eats Ltd | Hospitality | 2026 |
| Cooper Estates Harborough Limited | Real estate | 1990 |
| Cooper Group Investments Limited | Real estate | 2024 |
| Cooper Humphreys Consultancy Ltd | Professional & scientific | 2025 |
| Cooper Humphreys Ltd | Real estate | 2022 |
| Cooper Johnson Housing Ltd | Real estate | 2023 |
| Cooper Mouldings & Joinery Ltd | Manufacturing | 2026 |
| Cooper Residential Homes Limited | Health & social care | 1934 |
| Cooper Scaffolding Limited | Construction | 2011 |
| Cooper Street Investments Limited | Real estate | 2024 |
| Cooper's Upholstery Ltd | Other services | 2023 |
| Cooper-Thorpe Ltd | Construction | 2020 |
| Copacabar Ltd | Professional & scientific | 2026 |
| Copackersuk Limited | Administrative & support | 2023 |
| Copely Developments Limited | Manufacturing | 2009 |
| Coplodge Properties Limited | Real estate | 2006 |
| Coplow Auto Repairs Ltd | Wholesale & retail | 2016 |
| Coplow Cabins Ltd | Real estate | 2021 |
| Copper Beech Consultancy Limited | Professional & scientific | 2018 |
| Copper Beech Group Limited | Financial services | 2025 |
| Copper Meadow Management Company Limited | Households | 2023 |
| Copper TAP Collective Ltd | Hospitality | 2026 |
| Copperfield Investments Ltd | Real estate | 2020 |
| Copperfield Limited | Hospitality | 1998 |
| Coppice Court Residential Management Ltd | Real estate | 2008 |
| Coppice View (Rosliston) Management Company Limited | Real estate | 2021 |
| Copt Oak Carpentry Limited | Construction | 2017 |
| Copt Oak Developments Ltd | Real estate | 2023 |
| Copywriting Nerd Ltd | Professional & scientific | 2019 |
| Cora Solutions Ltd | Professional & scientific | 2023 |
| Corah Blanks Limited | Manufacturing | 2023 |
| Coral K Ltd | Real estate | 2011 |
| Corali Group Limited | Transport & logistics | 2021 |
| Corali Investments Limited | Real estate | 2022 |
| Corbett Cable Contractors Limited | Construction | 2003 |
| Corby and King Ltd | Administrative & support | 2025 |
| Cord Controls Limited | Manufacturing | 2003 |
| Cordex 1 Ltd | Wholesale & retail | 2025 |
| Cordion Limited | Administrative & support | 2025 |
| Core 4 Group Ltd | Financial services | 2026 |
| Core Carbon Ltd | Professional & scientific | 2024 |
| Core Care Capital Ltd | Financial services | 2026 |
| Core Decorators Limited | Construction | 2016 |
| Core Electrical Systems Limited | Construction | 2021 |
| Core Ground Services Limited | Construction | 2025 |
| Core KIT Ltd | Information & communication | 2024 |
| Core Motorsport Services Limited | Manufacturing | 2009 |
| Core Properties Leicester Limited | Real estate | 2021 |
| Core Properties Ltd | Real estate | 2020 |
| Corenex Partners Ltd | Administrative & support | 2026 |
| Coretwo Network Solutions Ltd | Information & communication | 2021 |
| Corhampton Haulage Ltd | Transport & logistics | 2014 |
| Coriarium IT Solutions Limited | Information & communication | 2016 |
| Coring Developments Limited | Financial services | 2025 |
| Corinos Properties Ltd | Real estate | 2026 |
| Corium Holdings Limited | Financial services | 2022 |
| Corium Solutions Limited | Manufacturing | 2003 |
| Corner Tree Limited | Real estate | 2012 |
| Cornerstone Business Insurance Limited | Financial services | 2010 |
| Cornerstone Care & Support Ltd | Health & social care | 2026 |
| Cornerstone Medical Education Ltd | Education | 2020 |
| Cornerstone Medical Supplies Ltd | Health & social care | 2023 |
| Cornerstone Nails & Beauty Ltd | Other services | 2026 |
| Cornerstone Property & Compliance Ltd | Administrative & support | 2026 |
| Cornmill Ltd | Hospitality | 2012 |
| Cornwall Conveniences Ltd | Administrative & support | 2016 |
| Coromandel (UK) Ltd | Wholesale & retail | 2015 |
| Coronation 151 Ltd | Real estate | 2025 |
| Coronation Services Ltd | Health & social care | 2026 |
| Coronet House Publishing Limited | Information & communication | 2008 |
| Corp Wala Limited | Wholesale & retail | 2026 |
| Corporate Accounting Services Limited | Administrative & support | 2018 |
| Corporate Driving Experiences Limited | Arts & recreation | 2026 |
| Corporate Leisure Limited | Wholesale & retail | 2006 |
| Corpotel (International) Ltd | Wholesale & retail | 2012 |
| Corps Socials Ltd | Information & communication | 2024 |
| Corpus Haven Ltd | Health & social care | 2025 |
| Corrah Healthcare Services Ltd | Health & social care | 2023 |
| Corral Engineering Ltd | Professional & scientific | 2025 |
| Correado Property Care Ltd | Construction | 2025 |
| Correo Ltd | Transport & logistics | 2021 |