| Corrigan Property Ltd | Real estate | 2017 |
| Corstorphine & Wright (Manchester) Ltd | Professional & scientific | 2012 |
| Cortez Bar Limited | Hospitality | 2021 |
| Corthorn Ltd | Transport & logistics | 2008 |
| Corvee Services Limited | Real estate | 2008 |
| Corvex Silbury Limited | Information & communication | 2025 |
| Cory Hubbard Motors Ltd | Wholesale & retail | 2025 |
| COS777 Ltd | Health & social care | 2017 |
| Cosbees Limited | Agriculture & fishing | 2026 |
| Cosby Golf Club Limited | Education | 2019 |
| Cosec Holdings Limited | Financial services | 2021 |
| Cosfop Ltd | Manufacturing | 2020 |
| Cosilan Systems Limited | Information & communication | 2025 |
| Cosmetology Hub Ltd | Other services | 2020 |
| Cosmic Carpets Ltd | Wholesale & retail | 2024 |
| Cosmic Chaos Creations Ltd | Manufacturing | 2025 |
| Cosmic Safari Ltd | Administrative & support | 2019 |
| Cosmic Trading Leic Ltd | Wholesale & retail | 2023 |
| Cosmic Travels Ltd | Administrative & support | 2026 |
| COSMIC360BULLIONS Ltd | Wholesale & retail | 2026 |
| Cosmin Ionut Cozma Ltd | Transport & logistics | 2024 |
| Cosmo Stark Ltd | Wholesale & retail | 2025 |
| Cosmo Trans Ltd | Transport & logistics | 2024 |
| Cosmonaut Entertainment Ltd | Information & communication | 2018 |
| Cosmopolitan Arts CIC | Arts & recreation | 2014 |
| Cosmos Aviation Ltd | Information & communication | 2022 |
| Cosmosity Ltd | Information & communication | 2021 |
| Cosmur Construction (London) Limited | Construction | 1973 |
| Cossington United CIC | Education | 2025 |
| Cossiwild Ltd | Hospitality | 2012 |
| Costa & Silva Construction Ltd | Construction | 2024 |
| Costa Construction Limited | Construction | 2011 |
| Costa Fish and Chips Shop Ltd | Hospitality | 2025 |
| Costain AMS Limited | Hospitality | 2020 |
| Costas Fish Bar Oadby Ltd | Hospitality | 2023 |
| Costass Ltd | Transport & logistics | 2017 |
| Costel - Cristian Transport Limited | Transport & logistics | 2019 |
| Costy ABD Ltd | Other services | 2017 |
| Cosy Catering Ltd | Hospitality | 2026 |
| Cosy Hair Lounge Limited | Other services | 2014 |
| Cosy Knits Ltd | Wholesale & retail | 2025 |
| Cosyhomesgoods Ltd | Manufacturing | 2025 |
| Cote Hill Developments Ltd | Construction | 2021 |
| Cottage Cards Limited | Arts & recreation | 2020 |
| Cottage Taste Limited | Hospitality | 2025 |
| Cotterill Hospitality Limited | Hospitality | 2024 |
| Cotton & Banks Limited | | 1961 |
| Cotton Mews Management Company Limited | Extraterritorial | 2010 |
| Countax Ltd | Professional & scientific | 2020 |
| Countesthorpe Aerials Limited | Construction | 2007 |
| Countesthorpe Blinds Limited | Wholesale & retail | 2006 |
| Countesthorpe Born and Bread Limited | Manufacturing | 2013 |
| Countesthorpe Commercials Limited | Wholesale & retail | 2024 |
| Countesthorpe Cricket Club Limited | Arts & recreation | 2020 |
| Country Canine Academy Ltd | Other services | 2026 |
| Country Club Cars Ltd | Wholesale & retail | 2022 |
| Country Developments Ltd | Construction | 2024 |
| Country Direct Limited | Wholesale & retail | 2021 |
| Country Fayre Foods Limited | Wholesale & retail | 2013 |
| Country Fields Gardens Limited | Wholesale & retail | 2017 |
| Countrywide Car Sales UK Ltd | Wholesale & retail | 2019 |
| County & Mcandrews Roofing Limited | Construction | 2015 |
| County & Shire Portfolio Ltd | Real estate | 2024 |
| County Conveyors Limited | Manufacturing | 1992 |
| County Diesel Limited | Manufacturing | 2010 |
| County Display (Leicester) Limited | Manufacturing | 1999 |
| County Electrical Services Limited | Construction | 2003 |
| County Fabrications Ltd | Manufacturing | 2026 |
| County Pharmacy (Leicester) Limited | Wholesale & retail | 2003 |
| County Properties Maintenance Ltd | Construction | 2024 |
| County Restorations Limited | Construction | 2003 |
| County Roofing (Leicester) Limited | Construction | 1999 |
| County Vehicle Ltd | Wholesale & retail | 2019 |
| Couperco Limited | Information & communication | 2020 |
| Court View (Leicester) Limited | Construction | 2007 |
| Court View Management Company Limited | Households | 2006 |
| Courtney Legal Group Limited | Other services | 2022 |
| Courtyard Close Management Limited | Construction | 2013 |
| Courtz Ltd | Wholesale & retail | 2025 |
| Cousans Organs Limited | Manufacturing | 2017 |
| Cousans Properties Ltd | Real estate | 2025 |
| Couture Eyewear Limited | Extraterritorial | 2024 |
| Covanna Ltd | Manufacturing | 2024 |
| Cove Car Company Ltd | Wholesale & retail | 2006 |
| Cove Carpentry Ltd | Manufacturing | 2023 |
| Cove Independent Travel Ltd | Transport & logistics | 2020 |
| Covenden Limited | Administrative & support | 2012 |
| Coventry Bowel Clinic Ltd | Health & social care | 2022 |
| Coventry Collective Ltd | Hospitality | 2025 |
| Cover Masters UK Ltd | Manufacturing | 2020 |
| Cover Story CLO Ltd | Wholesale & retail | 2025 |
| Covermed Healthcare Ltd | Administrative & support | 2020 |
| Covert Services INT Limited | Transport & logistics | 2024 |
| Covertec Solutions Ltd | Professional & scientific | 2007 |
| Cowells Small Machine Tools Limited | Manufacturing | 1997 |
| Cowman Civils Limited | Construction | 2020 |
| COX & Smallman (Engineering) Limited | Manufacturing | 1980 |
| COX Close Management Company Limited | Households | 2018 |
| COX Consultancy Limited | Professional & scientific | 2023 |
| Coxlease School Limited | Professional & scientific | 1990 |