| Courage Enterprises Ltd | Information & communication | 2019 |
| Courier Brewing Company Limited | Manufacturing | 2021 |
| Courierz Ltd | Transport & logistics | 2021 |
| Courix Ltd | Transport & logistics | 2025 |
| Course Completor Ltd | Education | 2024 |
| Course Tsunami Limited | Education | 2022 |
| Coursechange Limited | Health & social care | 1999 |
| Courseleaf Ltd | Wholesale & retail | 2025 |
| Courser Consulting Engineers Ltd | Professional & scientific | 2021 |
| Court Enforcement Specialists Limited | Public administration | 2018 |
| Courtleigh of London Limited | Professional & scientific | 1991 |
| Courtney's Hub Ltd | Information & communication | 2025 |
| Courts (Chester) Limited | Construction | 2020 |
| Courts (Northwich) Limited | Construction | 2020 |
| Courts (Wrexham) Limited | Construction | 2020 |
| Courts Developments Ltd | Construction | 2012 |
| Courts Developments SPV1 Limited | Construction | 2019 |
| Courts Equity Ltd | Construction | 2024 |
| Courts Investments Ltd | Administrative & support | 2012 |
| Courts Property Limited | Real estate | 2025 |
| Courtswrites Limited | Administrative & support | 2023 |
| Courtyard Homes Limited | Real estate | 2014 |
| Courtyard Leisure Limited | Hospitality | 2010 |
| Courtyard Living (Design and Build) Limited | Construction | 2023 |
| Courtyard Living Limited | Real estate | 2013 |
| Courtyard Property Consultants Limited | Professional & scientific | 2013 |
| Courtyard Studios Limited | Professional & scientific | 2026 |
| Cousin Properties Ltd | Real estate | 2019 |
| Cousins Connect Ltd | Hospitality | 2025 |
| Cousins Homes Ltd | Real estate | 2017 |
| Couterra Capital Limited | Financial services | 2026 |
| Couterra Holdings Limited | Financial services | 2026 |
| Couture Collective Ltd | Wholesale & retail | 2026 |
| Couture Social Ltd | Wholesale & retail | 2025 |
| Couturecharm Designs Ltd | Wholesale & retail | 2024 |
| Covarrubia Energy GAS UK Limited | Energy | 2026 |
| Covarrubia Energy Infrastructure UK Limited | Financial services | 2026 |
| Cove & Cloth Ltd | Wholesale & retail | 2023 |
| Cove Child Care Group Limited | Financial services | 2024 |
| Cove Child Care Limited | Health & social care | 2025 |
| Cove Child Care Services Limited | Professional & scientific | 2024 |
| Covecall Limited | Real estate | 1944 |
| Covenant Consular Solutions Ltd | Administrative & support | 2026 |
| Covenant Dynamics Ltd | Information & communication | 2024 |
| Coventina Manchester Ltd | Manufacturing | 2026 |
| Coventry Beech LP | | 2024 |
| Cover Express Ltd | Financial services | 2021 |
| Cover ME Warranty Ltd | Manufacturing | 2025 |
| Cover-Rule Limited | Financial services | 1989 |
| Coverasset Limited | Professional & scientific | 1991 |
| Covercraft Interiors Limited | Construction | 2025 |
| Coverdrive Manchester Ltd | Arts & recreation | 2025 |
| Coverlead Ltd | Professional & scientific | 2025 |
| Coverlease Limited | Real estate | 2004 |
| Coversell Ltd | Construction | 2020 |
| Covert Digital Ltd | Information & communication | 2026 |
| Covert Investigations Training Ltd | Education | 2025 |
| Covert Network Associates Limited | Administrative & support | 2007 |
| Covertclo Ltd | Wholesale & retail | 2023 |
| Coveva Clinics Ltd | Health & social care | 2023 |
| Covonderla Ltd | Transport & logistics | 2017 |
| Cow-Key Ltd | Real estate | 2021 |
| Cowabunga Burgers Ltd | Extraterritorial | 2025 |
| Coward & Kerr Limited | Construction | 2002 |
| Cowards Combs Ltd | Hospitality | 2026 |
| Cowie Construction Services Limited | Construction | 2024 |
| Cowley Legal Services Limited | Professional & scientific | 2020 |
| Cowley Motor Company Limited | Wholesale & retail | 2012 |
| COX & Co. Investments Ltd | Financial services | 2024 |
| COX and Robinson (Chemists) Limited | Extraterritorial | 1936 |
| COX and Robinson Pharmacy Limited | Extraterritorial | 1948 |
| COX Bazar Ltd | Hospitality | 2023 |
| COX Floorworks Ltd | Construction | 2025 |
| COX Property Solutions Ltd | Real estate | 2021 |
| Cox's Movers & Storage Ltd | Transport & logistics | 2021 |
| Coxhoe Hand Car Wash Ltd | Wholesale & retail | 2023 |
| Coxon Car Sales Ltd | Wholesale & retail | 2024 |
| Coyar Services Ltd | Construction | 2025 |
| Coyita Limited | Administrative & support | 2014 |
| Coyle Construction Services Limited | Construction | 2021 |
| Cozenswain Limited | Administrative & support | 2025 |
| Cozia Living Ltd | Wholesale & retail | 2026 |
| Cozimercer Limited | Arts & recreation | 2012 |
| Cozmic Rabbit Limited | Information & communication | 2025 |
| Cozmos Films Ltd | Information & communication | 2023 |
| Cozora Ltd | Wholesale & retail | 2026 |
| Cozy & Clean Limited | Administrative & support | 2025 |
| Cozy BNB Ltd | Households | 2026 |
| Cozy Carpet & Furniture Ltd | Wholesale & retail | 2025 |
| Cozy Cove Couture Ltd | Wholesale & retail | 2025 |
| Cozy Cravings Ltd | Hospitality | 2025 |
| Cozy Cubes Ltd | Real estate | 2022 |
| Cozy Curl Co Limited | Wholesale & retail | 2025 |
| Cozy Dream Ltd | Wholesale & retail | 2026 |
| Cozy Floors Ltd | Wholesale & retail | 2026 |
| Cozy Furniture Ltd | Wholesale & retail | 2024 |
| Cozy Home International Limited | Wholesale & retail | 2021 |
| Cozy House Property Management Limited | Real estate | 2024 |
| Cozy Luxury BED Ltd | Wholesale & retail | 2025 |
| Cozyb Limited | Health & social care | 2021 |