| Cosmeticaa Ltd | Wholesale & retail | 2020 |
| Cosmin Andrei Transporter Ltd | Manufacturing | 2026 |
| Cosmo Accountancy Ltd | Professional & scientific | 2008 |
| Cosmo Commercials Ltd | Real estate | 2022 |
| Costa Courier Express Limited | Transport & logistics | 2023 |
| Costays Management Ltd | Real estate | 2026 |
| Costcutter (Eston) Limited | Wholesale & retail | 2003 |
| Costica Painters Ltd | Construction | 2021 |
| Cotnoirs Ltd | Transport & logistics | 2021 |
| Cotton & Chintz Limited | Wholesale & retail | 1995 |
| Couchbound Games Ltd | Information & communication | 2025 |
| Coulby Carpet and Valeting Services Ltd | Administrative & support | 2023 |
| Coulby Communications Ltd | Information & communication | 2006 |
| Coulby Foods Ltd | Hospitality | 2024 |
| Coulby Newham Garden Services Ltd | Agriculture & fishing | 2023 |
| Coulby Newham Plumbing & Heating Limited | Construction | 2009 |
| Coulby Newham Properties Limited | Real estate | 2022 |
| Coulter Smith Construction Ltd | Construction | 2013 |
| Count on M3 Limited | Health & social care | 2019 |
| Country Retreats & Estates Limited | Hospitality | 2020 |
| Coupland Engineering Services Ltd | Construction | 2012 |
| Coupland Hall Inspection Services Limited | Other services | 2016 |
| Cousins & Co Limited | Professional & scientific | 2010 |
| Cowie Technology Group Limited | Manufacturing | 1965 |
| Cowley Rail (London) Limited | Professional & scientific | 2016 |
| Cowslip Engineering Consultants Limited | Professional & scientific | 2019 |
| CP Environmental Testing Ltd | Professional & scientific | 2024 |
| CP Property Partners Limited | Construction | 2023 |
| CP Riverside Ltd | Professional & scientific | 2017 |
| Cparuk Limited | Wholesale & retail | 2026 |
| Cpauk Limited | Wholesale & retail | 2026 |
| Cpbp Trading Limited | Administrative & support | 2018 |
| CPC Contract Flooring Limited | Construction | 2016 |
| CPD Products Ltd | Wholesale & retail | 2025 |
| CPH PUB Company Ltd | Hospitality | 2024 |
| CPM Consultancy Limited | Professional & scientific | 2026 |
| CPN Specialist Music Teaching Limited | Education | 2005 |
| CPS Facilities Management Limited | Administrative & support | 2025 |
| CPS North East Ltd | Wholesale & retail | 2018 |
| CPS Security Group Limited | Financial services | 2025 |
| CPW85 Ltd | Professional & scientific | 2025 |
| CR Electrics (North East) Ltd | Construction | 2018 |
| CR Fibretech Limited | Information & communication | 2024 |
| CR Property NE Ltd | Real estate | 2020 |
| CR Shares Ltd | Transport & logistics | 2026 |
| CR Sturdy Logistics Ltd | Transport & logistics | 2025 |
| Craft Crove Ltd | Wholesale & retail | 2023 |
| Craft Franchise Limited | Hospitality | 2024 |
| Crafton Equipment Hire Limited | Administrative & support | 2025 |
| Craig Cook Electrical Ltd | Construction | 2021 |
| Craig Currie Limited | Construction | 2008 |
| Craig John Limited | Wholesale & retail | 2023 |
| Cranbrook Financial Services Limited | Financial services | 2013 |
| Crane Aviation Limited | Hospitality | 2024 |
| Cranswick Engineering Ltd | Construction | 2015 |
| Crathorne Wealth Management Ltd | Financial services | 2022 |
| Craver's Corner Ltd | Hospitality | 2025 |
| Crawford Offshore (Exploration) Services Limited | Extraterritorial | 2005 |
| Crawford OIL (Exploration) Services Limited | Extraterritorial | 1999 |
| Crazy Corner Adventure Playcentre Ltd | Hospitality | 2012 |
| CRB Lifting Services Limited | Construction | 2017 |
| Create Talent Ltd | Professional & scientific | 2018 |
| Creation Paving Services Limited | Construction | 2017 |
| Creative Building Works Ltd | Construction | 2023 |
| Creative Factory Middlesbrough Limited | Arts & recreation | 2024 |
| Creative Hair & Beauty Centre Limited | Other services | 2010 |
| Creative Patio & Landscape Design Ltd | Administrative & support | 2019 |
| Creative Property Services NE Ltd | Real estate | 2022 |
| Creative Traders Limited | Real estate | 2022 |
| Creativealgo Ltd | Professional & scientific | 2024 |
| Creativeworker Limited | Professional & scientific | 2015 |
| Creeds Cars Ltd | Wholesale & retail | 2024 |
| Crescent Road Mini Market Limited | Wholesale & retail | 2026 |
| Crestwood Property Group Ltd | Real estate | 2023 |
| Cribview Ltd | Real estate | 2024 |
| Crierielis Transport Ltd | Transport & logistics | 2025 |
| Crimewatch Safeguard Monitoring and Patrol Limited | Administrative & support | 2014 |
| Crimewatch Safeguard Security Systems Ltd. | Administrative & support | 2003 |
| Crimewatch Systems Ltd | Administrative & support | 1995 |
| Crinac Ltd | Wholesale & retail | 2025 |
| Critical Failure Games Ltd | Information & communication | 2021 |
| Critical Failure UK Ltd | Information & communication | 2021 |
| Critical Material Recovery Limited | Professional & scientific | 2023 |
| Crmc Limited | Professional & scientific | 2019 |
| Crocker Properties Limited | Real estate | 2019 |
| Croft Consultancy (NE) Ltd | Construction | 2017 |
| Croft Joinery Services Limited | Construction | 2026 |
| Croft Rigging and Lifting Ltd | Construction | 2021 |
| Cromas Offshore Ltd | Health & social care | 2021 |
| Cromas Offshore Rentals Limited | Health & social care | 2022 |
| Crone Interiors Limited | Professional & scientific | 2018 |
| Crone Rentals Limited | Real estate | 2018 |
| Cross Connection Ltd | Wholesale & retail | 2022 |
| Cross-Sector Ltd | Construction | 2025 |
| Crossco (1255) Limited | Professional & scientific | 2011 |
| Crossco (1437) Limited | Financial services | 2018 |
| Crossco (1438) Limited | Financial services | 2018 |
| Crossco B1 Investments Limited | Financial services | 2023 |
| Crossco B2 Investments Limited | Financial services | 2023 |
| Crossco D1 Investments Limited | Financial services | 2023 |