| Conway Precision Engineering Group Limited | Manufacturing | 1962 |
| Conwy Cwtch Ltd | Real estate | 2023 |
| COO Network Ltd | Administrative & support | 2020 |
| Coodex Ltd | Professional & scientific | 2025 |
| Coogee Nursery School Limited | Education | 2004 |
| Cook,S Trading Company Limited | Wholesale & retail | 2011 |
| Cooke Investments Ltd | Real estate | 2017 |
| Cooke Rudling Limited | Real estate | 2011 |
| Cooked Food Ltd | Hospitality | 2025 |
| Cookes Bathrooms Limited | Wholesale & retail | 2023 |
| Cookes Furniture (Holdings) Limited | Financial services | 2014 |
| Cookes Furniture Limited | Wholesale & retail | 1976 |
| Cookham Thai Ltd | Hospitality | 2026 |
| Cookie Solutions Ltd | Professional & scientific | 2024 |
| Cookie Wagon Ltd | Manufacturing | 2024 |
| Cookies 'N' Creme Ltd | Hospitality | 2020 |
| Cookies Crew Clothing Limited | Manufacturing | 2015 |
| Cooking 2 Connect CIC | Hospitality | 2026 |
| Cooks Lane and Gressel Lane Management Limited | Administrative & support | 1996 |
| Cookson Cyber Security Ltd | Information & communication | 2023 |
| Cooksters Ltd | Wholesale & retail | 2023 |
| Cooky Dough Ltd | Hospitality | 2014 |
| Cool Breeze Refrigeration Ltd | Construction | 2026 |
| Cool Buyer Ltd | Administrative & support | 2026 |
| Cool Jade Limited | Wholesale & retail | 2011 |
| Cool R US Ltd | Construction | 2025 |
| Cool Refrigeration (Midlands) Ltd | Administrative & support | 2016 |
| Cool Runnings Tyres Ltd | Wholesale & retail | 2022 |
| Cool Technology Limited | Manufacturing | 1969 |
| Cool.Ecomuk Ltd | Wholesale & retail | 2025 |
| Cooling Components Limited | Wholesale & retail | 2003 |
| Coolmax Limited | Energy | 2018 |
| Coolmoove Property Limited | Real estate | 2022 |
| Coolpilates Ltd | Health & social care | 2011 |
| Coolref Ltd | Construction | 2019 |
| Coombes Lane Stores Ltd | Wholesale & retail | 2020 |
| Coombes Traffic Management Limited | Public administration | 2019 |
| Coombswood Limited | Real estate | 2021 |
| Cooney Gastro Limited | Health & social care | 2024 |
| Cooper Biscayne Limited | Arts & recreation | 2026 |
| Cooper Caden LLP | | 2010 |
| Cooper Catering Ltd | Hospitality | 2013 |
| Cooper Mechanics Ltd | Wholesale & retail | 2025 |
| Cooper Tire & Rubber Company Europe Limited | Manufacturing | 1918 |
| Cooper Tyre & Rubber Company UK Limited | Professional & scientific | 1996 |
| Cooper Young Communications Limited | Administrative & support | 2013 |
| Cooper's Cocktails Ltd | Wholesale & retail | 2021 |
| Coopers Butchers Limited | Wholesale & retail | 2013 |
| Coopers Carpentry Contractors Limited | Construction | 2000 |
| Coopers Chase Management Company Limited | Households | 2024 |
| Coopers Court (Cheltenham) Management Company Limited | Real estate | 2013 |
| Coopers Hill (Bracknell) Management Company Limited | Households | 2023 |
| Coopers Hill Bakery Ltd | Wholesale & retail | 2025 |
| Coopers Needle Works Limited | Manufacturing | 1936 |
| Coopers of Birmingham Limited | Wholesale & retail | 2003 |
| Coote Railway Engineering Ltd | Construction | 2019 |
| Coozo Creative Solutions Limited | Wholesale & retail | 2008 |
| COP Construction Limited | Construction | 2025 |
| Copacetic Ltd | Wholesale & retail | 2023 |
| Cope Care Services Ltd | Health & social care | 2023 |
| Copeley Gardens U.K. Ltd | Households | 2021 |
| Copello Associates Ltd | Health & social care | 2022 |
| Copes Potatoes (Midlands) Ltd | Wholesale & retail | 2007 |
| Copex Limited | Hospitality | 2004 |
| Copex Services Ltd | Real estate | 2025 |
| Coppen PPC Ltd | Professional & scientific | 2024 |
| Copper & ASH Design Ltd | Professional & scientific | 2020 |
| Copper & Grey Limited | Professional & scientific | 2024 |
| Copper Beach Limited | Real estate | 2008 |
| Copper Beech House Management Limited | Households | 2017 |
| Copper Forest Consulting Ltd | Professional & scientific | 2022 |
| Copper Hearts UK Ltd | Arts & recreation | 2023 |
| Copper Thread Productions Limited | Information & communication | 2022 |
| Copper Top Productions Limited | Arts & recreation | 2010 |
| Copperfields Management (West Midlands) Limited | Households | 2006 |
| Coppermill Lock Ltd | Real estate | 2024 |
| Coppice Care Club and Pre-School Limited | Education | 2012 |
| Coppice Childcare - Shard END Limited | Health & social care | 2017 |
| Coppice House Management Limited | Households | 2005 |
| Copple Consultancy Services Limited | Information & communication | 2015 |
| Coppola Van Delivery Ltd | Transport & logistics | 2026 |
| Cops 2020 Limited | Administrative & support | 2020 |
| Copson Construction Ltd | Construction | 2025 |
| Copt Heath Holdings Ltd | Health & social care | 2021 |
| Copthorne Brick Ltd | Hospitality | 2020 |
| COR125 CIC | Hospitality | 2023 |
| Cora & Adam Ltd | Construction | 2020 |
| Cora's Hair & Beauty Limited | Other services | 2013 |
| Coral Lotus Ltd | Arts & recreation | 2025 |
| Coram Life Education West Mercia | Education | 2002 |
| Corax ILS Ltd | Professional & scientific | 1998 |
| Corbesley Properties Limited | Real estate | 2012 |
| Corbett BLU Ltd | Wholesale & retail | 2026 |
| Corbett Homes Investment Limited | Real estate | 2020 |
| Corbett Mechanical Ltd | Construction | 2025 |
| Corby Fish & Chips Ltd | Hospitality | 2020 |
| Corby Private Hire Ltd | Transport & logistics | 2025 |
| Corclaim LLP | | 2021 |
| Cord Power Technologies Ltd | Wholesale & retail | 2023 |
| Cordal Construction Ltd | Construction | 2025 |