| Correca Ltd | Construction | 2018 |
| Corrigan & Chapman Construction Ltd | Construction | 2008 |
| Corrigan & Chapman Maintenance Ltd | Construction | 2020 |
| Corrigan & Chapman Projects Ltd | Construction | 2020 |
| Corringham Park 2 Limited | Real estate | 2025 |
| Corringham Park Ltd | Real estate | 2023 |
| Corros Limited | Construction | 2017 |
| Corstor Limited | Transport & logistics | 1999 |
| Cortex Plumbing & Heating Engineering Ltd | Construction | 2016 |
| Coscol Fixing Ltd | Construction | 2020 |
| Cosem Limited | Professional & scientific | 2007 |
| Cosgem Orton Limited | Construction | 1995 |
| Cosgrove Cleaning Services Limited | Administrative & support | 2024 |
| Cosmetic Education Hub Ltd | Education | 2025 |
| Cosmix Drywall Limited | Construction | 2020 |
| Cosmoquins Ltd | Wholesale & retail | 2025 |
| Cosmos Fitted Furniture Ltd. | Manufacturing | 1993 |
| Cosmotrade Shipping Ltd | Transport & logistics | 2017 |
| Cospect Expert Ltd | Construction | 2021 |
| Costa Dynamic Services Ltd | Health & social care | 2016 |
| Costi&Sons Ltd | Transport & logistics | 2018 |
| Cosy Cubs Play Cafe Ltd | Arts & recreation | 2026 |
| Cottle's Castles Limited | Arts & recreation | 2023 |
| Cotton Buddies Limited | Education | 2014 |
| Couldron Dagda Ltd | Hospitality | 2025 |
| Countdown Recruitment Ltd | Administrative & support | 2020 |
| Country Boltholes Limited | Real estate | 2019 |
| Country Mile Design Ltd | Professional & scientific | 2018 |
| County Electrical (Property) Solutions Ltd | Real estate | 2025 |
| County Electrical Solutions Limited | Construction | 2008 |
| County Repairs Limited | Manufacturing | 2024 |
| County Wines Ltd | Wholesale & retail | 2025 |
| Cousin Carwash Limited | Other services | 2025 |
| Couza Limited | Professional & scientific | 2025 |
| Covad Construct Ltd | Construction | 2026 |
| Covenant Investments Limited | Extraterritorial | 2022 |
| Covenant Security Group Limited | Administrative & support | 2024 |
| Cover Global Ltd | Mining & quarrying | 2026 |
| Cover Solutions Limited | Information & communication | 2006 |
| Coverupsuk Ltd | Wholesale & retail | 2025 |
| Cowley Energy Reserve 2 Limited | Construction | 2023 |
| Cowtown Media Limited | Information & communication | 2007 |
| COX & Co Mechanical Services Ltd | Construction | 2012 |
| Coyle Capital Ltd | Real estate | 2025 |
| Cozzi Property Company Ltd | Real estate | 2024 |
| CP (Leeds) Limited | Hospitality | 2003 |
| CP Imperial Decor Ltd | Construction | 2023 |
| CP Leisurewear Limited | Wholesale & retail | 2020 |
| CP Roofing and Building Limited | Construction | 2024 |
| CP Utility Solutions Limited | Construction | 2023 |
| CPK Scaffolding Ltd | Construction | 2023 |
| CPM Renewables Limited | Energy | 2025 |
| CPP Drylining Ltd | Construction | 2023 |
| CPR 1 LLP | | 2022 |
| CPR Professional Services Ltd | Professional & scientific | 2016 |
| CPW Solutions Limited | Construction | 2005 |
| CPX Geoservices Ltd | Construction | 2023 |
| CQ Manor Park Limited | Construction | 2023 |
| CR Builder Maintain Ltd | Construction | 2016 |
| CR Financial Consulting Limited | Professional & scientific | 2016 |
| CR8TIVE Solutions Ltd | Information & communication | 2020 |
| CR8TIVE SPV Ltd | Real estate | 2026 |
| CR8TIVE Strategic Advisory Ltd | Professional & scientific | 2026 |
| Crafted Realms Ltd | Manufacturing | 2025 |
| Crafters Book Publishing Limited | Information & communication | 2025 |
| Craftmen Ltd. | Construction | 2018 |
| Crainiate Limited | Information & communication | 2001 |
| Cranberry Marketing Consultancy Limited | Professional & scientific | 2014 |
| Cranbrook (Ilford) Limited | Real estate | 2024 |
| Cranbrook House Dental Practice Limited | Health & social care | 2012 |
| Crane Apartments Limited | Real estate | 2010 |
| Crane Investments Ltd | Real estate | 2008 |
| Cranfield Construction Limited | Construction | 2022 |
| Cranfield Paper Recycling Ltd | Water & waste | 2013 |
| Cranford Property Services (Romford) Ltd | Real estate | 2012 |
| Cravendale Investments Ltd | Real estate | 2014 |
| Crawford Cook Ltd | Construction | 2016 |
| Cray Transport Services Limited | Transport & logistics | 2021 |
| Crazed Fashions Limited | Wholesale & retail | 2012 |
| Crazy Burgers Ltd | Hospitality | 2026 |
| Crazy Seller Ltd | Wholesale & retail | 2025 |
| CRC Rail Ltd | Construction | 2018 |
| CRD Therapy and Counselling Services Limited | Health & social care | 2024 |
| Cre-Ah Homes Ltd | Real estate | 2025 |
| CRE8TIVE Media Ltd | Administrative & support | 2020 |
| Creatio Studium Ltd | Extraterritorial | 2024 |
| Creativ.I Ltd | Wholesale & retail | 2025 |
| Creative & Unique Ltd | Real estate | 2026 |
| Creative Associate Limited | Wholesale & retail | 2010 |
| Creative Business Support Ltd | Administrative & support | 2023 |
| Creative Connexions Limited | Professional & scientific | 2019 |
| Creative Edge Kitchens Ltd | Manufacturing | 2016 |
| Creative Explorers Ltd | Professional & scientific | 2024 |
| Creative Investment Properties Limited | Real estate | 2025 |
| Creative Kids Pre-School Day Nursery Limited | Education | 1996 |
| Creative Property Assets Limited | Real estate | 2016 |
| Creative Property Mastery Limited | Administrative & support | 2016 |
| Creative Pros Ltd | Professional & scientific | 2023 |
| Creators the Consultants Ltd | Professional & scientific | 2019 |
| Credenta Ltd | Information & communication | 2025 |