| Cart Properties Ltd | Real estate | 2012 |
| Cartel Group Limited | Financial services | 2019 |
| Carter-Horseley (Engineers) Limited | | 1948 |
| Cartjoy Ltd | Wholesale & retail | 2023 |
| Cartmell Medical Services Limited | Health & social care | 2021 |
| Cartridge Tech Limited | Information & communication | 2006 |
| Casa Antonio Limited | Hospitality | 1997 |
| Casa DE Thorpe Ltd | Real estate | 2023 |
| Casa Golf Homes Limited | Other services | 2012 |
| Casa Loca Ltd | Wholesale & retail | 2025 |
| Casa One SIP Trustee Limited | Extraterritorial | 2016 |
| Casa REA Limited | Real estate | 2016 |
| Casablanca (Chittagong) Ltd | Health & social care | 2015 |
| Casabrigo Ltd | Real estate | 2025 |
| Cascom Limited | Information & communication | 2005 |
| Cascomm Ltd | Information & communication | 2025 |
| Caseley Properties Ltd | Real estate | 2020 |
| Cash 4 Motor Ltd | Wholesale & retail | 2016 |
| Cash Caddy Ltd | Wholesale & retail | 2025 |
| CASH2CRYPTO Ltd | Information & communication | 2023 |
| Caskwise Ltd. | Wholesale & retail | 2023 |
| Casmax Holdings Ltd | Financial services | 2023 |
| Casper Logistics Limited | Transport & logistics | 2009 |
| Caspian Health Limited | Wholesale & retail | 2025 |
| Caspian Turkish Cuisine Limited | Hospitality | 2016 |
| Cassini Films Ltd | Information & communication | 2021 |
| Castillion Aerospace Limited | Energy | 2000 |
| Castle 55 Ltd | Construction | 2022 |
| Castle Close Community Limited | Real estate | 2009 |
| Castle Dental Practice Limited | Health & social care | 2008 |
| Castle Electronic Technology Holdings Limited | Extraterritorial | 2012 |
| Castle Farmers Ltd | Wholesale & retail | 2024 |
| Castle Garth (Bamburgh) Management Company Limited | Real estate | 2009 |
| Castle Keep Financial Solutions Limited | Financial services | 2018 |
| Castle Peak Group Ltd | Administrative & support | 2024 |
| Castle Stairs Limited | Hospitality | 2023 |
| Castle Tower Mortgages Limited | Financial services | 2025 |
| Castle View (Horsley) Management Limited | Real estate | 2002 |
| Castle View (Skelton) Management Company Limited | Real estate | 2014 |
| Castlebow Limited | Real estate | 2013 |
| Castledene Developments Ltd | Construction | 2020 |
| Castlefield (Warkworth) Management Company Limited | Real estate | 2006 |
| Castlegate (Berwick-Upon-Tweed) Limited | Wholesale & retail | 2016 |
| Castlegate (Skelton) Management Company Limited | Real estate | 2022 |
| Castlegate Management Company (Bamburgh) Limited | Real estate | 2009 |
| Castlegate Property Company Limited | Real estate | 1947 |
| Castlegate Psychology Limited | Professional & scientific | 2014 |
| Castlepoint Coaching Ltd | Professional & scientific | 2023 |
| Castlethorpe Properties Limited | Real estate | 2018 |
| Castrius Capital Partners Limited | Financial services | 2025 |
| Castrius Investment Holdings Limited | Financial services | 2025 |
| Castrius Venture Accelerator Limited | Financial services | 2025 |
| Casw Propco Limited | Households | 2025 |
| Catalyst 4 Professional Sports Management Limited | Other services | 2017 |
| Catalyst Allstars CIC | Arts & recreation | 2021 |
| Catbol Media and Marketing Ltd | Professional & scientific | 2021 |
| Caterlytix Ltd | Information & communication | 2025 |
| Caterventure Limited | Hospitality | 1995 |
| Catfat LP | | 2017 |
| Catherine Fowle Legal Services Limited | Professional & scientific | 2018 |
| Catherine Trillo Interiors Ltd | Wholesale & retail | 2019 |
| Catherinesitalianpizza Ltd | Hospitality | 2026 |
| Cathie Associates Limited | Professional & scientific | 2006 |
| Catpawcino Ltd | Hospitality | 2015 |
| Cattell Foggoa Ltd | Real estate | 2025 |
| Cattra Actuarial Consulting Ltd | Financial services | 2018 |
| Cauldwell Gardens Management Company Ltd | Households | 2004 |
| Caulfield Pharma Consulting Ltd | Professional & scientific | 2019 |
| Causeway Productions Ltd | Information & communication | 2026 |
| Causey Arch Ltd | Hospitality | 2016 |
| CAV Systems Group Limited | Other services | 2017 |
| CAV Systems Holdings Limited | Other services | 2017 |
| Cava Living Limited | Real estate | 2021 |
| Cave Studios NCL Ltd | Real estate | 2025 |
| Caveman Consultants Limited | Information & communication | 2006 |
| Cavemanwf News Limited | Information & communication | 2025 |
| Cavendish Integrity Services Limited | Professional & scientific | 2025 |
| Cavenor Temple and Taubes Limited | Administrative & support | 2013 |
| Caviar Productions Ltd | Information & communication | 2024 |
| Caviar Studios Ltd | Information & communication | 2022 |
| Cavtec Systems Limited | Manufacturing | 2003 |
| Cavu Corporate Finance Limited | Professional & scientific | 2013 |
| Cawdor Blackwood Ltd | Real estate | 2019 |
| Caygill Associates Ltd. | Professional & scientific | 2014 |
| Caztec Group Limited | Construction | 2007 |
| CB Learning and Development Ltd | Administrative & support | 2011 |
| CB Joinery & Building Limited | Construction | 2015 |
| CB Joinery and Build Ltd | Construction | 2019 |
| CB Technologies Limited | Professional & scientific | 2018 |
| CB Wind NE Ltd | Construction | 2025 |
| CBE Awards Limited | Education | 2024 |
| Cbme Holdings Ltd | Real estate | 2022 |
| CBP UK Enterprises Limited | Information & communication | 2013 |
| CBS International Trading Limited | Wholesale & retail | 2006 |
| CC Companies Holdings Limited | Financial services | 2024 |
| CC Consultancy North East Limited | Real estate | 2020 |
| CC Makeup Artists Ltd | Other services | 2017 |
| CC North East Limited | Households | 2024 |
| CC Physio Ltd | Other services | 2025 |
| CC Recovery Solutions Ltd | Administrative & support | 2017 |