| CTO Partnership Limited | Professional & scientific | 2022 |
| CTR Steel Limited | Manufacturing | 2011 |
| CTS Environmental Services Ltd | Water & waste | 2009 |
| Cturner Properties Ltd | Real estate | 2024 |
| CTW Holdings 2018 Limited | Manufacturing | 2018 |
| CTW Holdings 2024 Ltd | Manufacturing | 2024 |
| Cuban Trading Partnerships Limited | Other services | 2010 |
| Cubbins Catering Ltd | Hospitality | 2016 |
| Cubbrinis Ltd | Hospitality | 2025 |
| Cube H Limited | Real estate | 2020 |
| Cubed Commercial Services Ltd | Professional & scientific | 2023 |
| Cubed-E Ltd | Professional & scientific | 2025 |
| Cubehand Limited | | 1984 |
| Cubi Building Ltd | Construction | 2022 |
| Cubic M3 Limited | Construction | 2017 |
| Cubikit Limited | Manufacturing | 2018 |
| Cubley Hall Limited | Hospitality | 2016 |
| Cudlarpets Limited | Wholesale & retail | 2025 |
| Cuespeak Limited | Information & communication | 2020 |
| Culf Construction Limited | Construction | 2013 |
| Cullen.Metcalfe & Co.Limited | Wholesale & retail | 1969 |
| Cullypubco Limited | Hospitality | 2025 |
| Cull’S Climate Solutions Ltd | Construction | 2019 |
| Cultivos Capital Ltd | Professional & scientific | 2020 |
| Cultural Inclusive C.I.C. | Hospitality | 2024 |
| Cultural Living Group Limited | Real estate | 2019 |
| Culture Club for Kids Ltd | Education | 2024 |
| Culture Tales Education & Projects C.I.C. | Information & communication | 2024 |
| Culture Vision Limited | Information & communication | 2022 |
| Culyer Homes Ltd | Real estate | 2023 |
| Cumberland Close 1976 Limited | Extraterritorial | 2014 |
| Cundy and Co Ltd | Real estate | 2022 |
| Cundy Electrical Limited | Construction | 2008 |
| Cunniff Design Limited | Professional & scientific | 2015 |
| Cunningham Browne LLP | | 2021 |
| Cup&Crumb Cafe Ltd | Manufacturing | 2025 |
| Cupola Contemporary Art (South Yorkshire) Limited | Arts & recreation | 2009 |
| Cuppa Teas Ltd | Wholesale & retail | 2024 |
| Cuppers Choice Ltd | Manufacturing | 2020 |
| Cura Nostra Ltd | Arts & recreation | 2012 |
| Cura Terrae Air Limited | Manufacturing | 1983 |
| Cura Terrae Land and Nature Limited | Professional & scientific | 2000 |
| Cura Terrae Limited | Professional & scientific | 2021 |
| Cura Terrae Midco Limited | Financial services | 2022 |
| Cura Terrae OH and Emissions Testing Limited | Professional & scientific | 1994 |
| Cura Terrae Topco Limited | Financial services | 2022 |
| Cura Terrae Water Limited | Information & communication | 2002 |
| Cura Workforce Solutions Ltd | Administrative & support | 2024 |
| Curator + Ltd | Information & communication | 2025 |
| Cure Roofing Limited | Construction | 2015 |
| Curiosity Shop HQ Limited | Information & communication | 2026 |
| Curious Little Minds Ltd | Education | 2026 |
| Curious Thinking Limited | Professional & scientific | 2014 |
| Curious Tiger Limited | Administrative & support | 2022 |
| Curious Venues North West Ltd | Hospitality | 2021 |
| Curious-Kidstown Ltd | Education | 2017 |
| Curlew Getaways Limited | Hospitality | 2020 |
| Curlew Hall Limited | Real estate | 2015 |
| Currach Limited | Health & social care | 2019 |
| Curran Communications (Hillsborough) Ltd | Professional & scientific | 2022 |
| Current Media Limited | Administrative & support | 2000 |
| Curry Boost Ltd | Hospitality | 2024 |
| Curry Cardamom Ltd | Hospitality | 2023 |
| Curry Divine Ltd | Hospitality | 2025 |
| Curry Express Kitchen Ltd | Hospitality | 2026 |
| Curry Hive Ltd | Hospitality | 2024 |
| Curry UP Limited | Hospitality | 2026 |
| Currys Forever Ltd | Hospitality | 2025 |
| Currys in Style Ltd | Hospitality | 2019 |
| Curtis Power & Co. Limited | Administrative & support | 1960 |
| Curts Properties Ltd | Real estate | 2025 |
| Curv Creative Ltd | Information & communication | 2015 |
| Custom Beverage Services Ltd | Hospitality | 2018 |
| Custom Brakes & Hydraulics Limited | Manufacturing | 1980 |
| Custom Branding Limited | Manufacturing | 2019 |
| Custom Built Campervans Limited | Wholesale & retail | 2017 |
| Custom Content Holdings Ltd | Manufacturing | 2022 |
| Custom Content Technology Ltd | Information & communication | 2021 |
| Custom Haulage Limited | Transport & logistics | 2009 |
| Custom Home Care Ltd | Health & social care | 2014 |
| Custom Stock Limited | Manufacturing | 2008 |
| Custom Vans & Cosmetic Repair Centre Limited | Wholesale & retail | 2015 |
| Custombuilt Ltd | Construction | 2003 |
| Customer Value Consulting Limited | Administrative & support | 2024 |
| CUT & Fold Solutions Ltd | Construction | 2017 |
| Cutcraft Limited | Construction | 2026 |
| Cute Children Gifts Limited | Wholesale & retail | 2025 |
| Cutiq Ltd | Information & communication | 2026 |
| Cutler and Key Properties Ltd | Real estate | 2023 |
| Cutler's Spice Limited | Hospitality | 2025 |
| Cutlers Cafe Ltd | Hospitality | 2021 |
| Cutpro Industrial Ltd | Manufacturing | 2025 |
| Cutslo Marketing Ltd | Information & communication | 2021 |
| Cutting & Wear Resistant Developments Limited | Manufacturing | 1968 |
| Cutting and Wear Limited | Extraterritorial | 1998 |
| Cutting Edge (Woodwork) Limited | Manufacturing | 2002 |
| Cutting Edge Decor Ltd | Professional & scientific | 2017 |
| Cutting Edge Laser Holdings Limited | Financial services | 2020 |
| Cutting Edge Laser Limited | Manufacturing | 2013 |
| Cutting Fitness Consulting Ltd | Arts & recreation | 2022 |