| Cooperate Property Limited | Real estate | 2024 |
| Coopers Roofing Services Ltd | Construction | 2023 |
| COP UK Limited | Extraterritorial | 2000 |
| Copeman Hart & Company Limited | Manufacturing | 1961 |
| Coppice Bazar Ltd | Wholesale & retail | 2022 |
| Coppice Cars Ltd | Wholesale & retail | 2020 |
| Coppice Kurry House Limited | Hospitality | 2016 |
| Coracow Limited | Real estate | 2011 |
| Core Climb Ltd | Construction | 2026 |
| Core Electrics Ltd | Construction | 2022 |
| Core Initiative Ltd | Administrative & support | 2016 |
| Core Migration Experts Ltd | Professional & scientific | 2023 |
| Core Progress Ltd | Health & social care | 2022 |
| Core SEF Limited | Construction | 2025 |
| Core Unity Ltd | Administrative & support | 2025 |
| Coregoods Trading Ltd | Wholesale & retail | 2026 |
| Coreloop AI Limited | Wholesale & retail | 2025 |
| Coreprop Holdings Ltd | Real estate | 2021 |
| Coreprop Limited | Real estate | 2012 |
| Corespan Data Ltd | Information & communication | 2026 |
| Coresupport UK Services Limited | Wholesale & retail | 2025 |
| Coreview Property Inspections Ltd | Professional & scientific | 2026 |
| Corian Estates Limited | Real estate | 2011 |
| Corlett Kitchens Limited | Manufacturing | 2022 |
| Cornbrook Developments Limited | Construction | 2016 |
| Cornbrook Limited | Information & communication | 1995 |
| Cornerhouse Day Nursery Ltd | Education | 2012 |
| Cornerstone Childminding Ltd | Health & social care | 2020 |
| Cornerstone Design & Marketing Limited | Professional & scientific | 2010 |
| Cornerstone Estates and Lettings Limited | Real estate | 2017 |
| Cornerstone Home and Property Ltd | Real estate | 2022 |
| Cornerstone Property INV Ltd | Real estate | 2023 |
| Cornwood Ltd | Professional & scientific | 2019 |
| Coronation ST Apartments Limited | Real estate | 2021 |
| Corporate Advice Partners LLP | | 2009 |
| Corporate Flight Services Limited | Transport & logistics | 2026 |
| Corporate Lettings and Management Ltd | Real estate | 2021 |
| Corrinne Goodall (Sports Management) Ltd | Professional & scientific | 2017 |
| Corris Leggat Ltd | Education | 2016 |
| Cost Cutting Solutions Ltd. | Information & communication | 2013 |
| Costello Flooring Limited | Construction | 2015 |
| Costello Wellness Community Interest Company | Arts & recreation | 2025 |
| Cosybuilt Ltd | Wholesale & retail | 2026 |
| Cotec Converting Machinery Limited | Manufacturing | 1988 |
| Cotemans Farm Limited | Agriculture & fishing | 2024 |
| Cotemede News Limited | Wholesale & retail | 2002 |
| Country Oven (Holdings) Limited | Professional & scientific | 2000 |
| Country Oven (Manchester) Limited | Manufacturing | 1985 |
| County END Electrical (North West) Ltd | Administrative & support | 2011 |
| County Minibuses Limited | Transport & logistics | 2022 |
| County Travels Ltd | Administrative & support | 2023 |
| Countywise Property Investments Ltd | Real estate | 2025 |
| Courier House Management Company Limited | Households | 2018 |
| Coushonn Ltd | Professional & scientific | 2025 |
| Covy Childrens Homes Ltd | Health & social care | 2023 |
| Covy Community Living Ltd | Health & social care | 2025 |
| Covy Education Training and Consultancy Ltd | Administrative & support | 2026 |
| Cowlabs Ltd | Information & communication | 2023 |
| Cowlishaw Residents Green Space Limited | Extraterritorial | 2011 |
| Cozy Corner Home Textiles Ltd | Wholesale & retail | 2026 |
| Cozy Homez Limited | Real estate | 2024 |
| Cozy Koala Studios Ltd | Wholesale & retail | 2025 |
| CP Surveillance Limited | Professional & scientific | 2024 |
| Cpgmclair Ltd | Information & communication | 2024 |
| CPL Holdings (UK) Limited | Hospitality | 2000 |
| CPL Installations Ltd | Extraterritorial | 1998 |
| Cplh Group Ltd | Construction | 2024 |
| CPS Building Contractors Ltd | Construction | 2025 |
| Craft & Crave Ltd | Hospitality | 2025 |
| Craft Bespoke Joinery Limited | Construction | 2016 |
| Craft Housing Ltd | Financial services | 2016 |
| Craftyagi Limited | Professional & scientific | 2024 |
| Craig Collier Limited | Manufacturing | 1997 |
| Crane NXT Pension Trustee Company (UK) Limited | Financial services | 2023 |
| Crane Payment Innovations International Ltd | Administrative & support | 2006 |
| Cranmer Education Trust | Education | 2011 |
| Crate Ideas & Designs Ltd | Administrative & support | 2012 |
| Crauren Properties Ltd | Real estate | 2024 |
| Crave Cabin Ltd | Hospitality | 2025 |
| Crave Culture Ltd | Hospitality | 2023 |
| Crave UK Holdings Ltd | Hospitality | 2025 |
| Cravecraft Ltd | Other services | 2025 |
| Crawford Property Management Limited | Real estate | 2007 |
| CRB Innovations Ltd | Professional & scientific | 2025 |
| Cream-Faced Loons Theatre Company CIC | Education | 2019 |
| Create & Develop Resourcing Limited | Administrative & support | 2015 |
| Createaweb Ltd | Information & communication | 2025 |
| Creativax AI Limited | Wholesale & retail | 2025 |
| Creative Architecture Limited | Professional & scientific | 2014 |
| Creative Builds Oldham Limited | Construction | 2018 |
| Creative Drives Oxfordshire Ltd | Construction | 2025 |
| Creative Flare Broadcast Engineering Limited | Information & communication | 2023 |
| Creative Forge Ltd | Professional & scientific | 2018 |
| Creative Holdings Ltd | Construction | 2015 |
| Creative LED Ltd | Information & communication | 2014 |
| Creative Locations Limited | Agriculture & fishing | 2011 |
| Creative of Oxford Ltd | Construction | 2024 |
| Creative Roofing Ltd | Construction | 2026 |
| Creativity Box CIC | Education | 2023 |
| Credence Commerce Ltd | Wholesale & retail | 2026 |