| Cucumber Eco Renewables Ltd | Energy | 2025 |
| Cucumber Eco Solutions Ltd | Professional & scientific | 2018 |
| Cucumber Investments (Holdings) Limited | Financial services | 2024 |
| Cucumber Investments Ltd | Real estate | 2019 |
| Cucumber Logistics Ltd | Administrative & support | 2021 |
| Cucumber Partners Ltd | Administrative & support | 2026 |
| Cucumber Recruitment (Holdings) Limited | Financial services | 2024 |
| Cucumber Recruitment Limited | Administrative & support | 2018 |
| Cucumber Trading Limited | Wholesale & retail | 2025 |
| Cuddle & Color Ltd | Wholesale & retail | 2025 |
| Cuddleco Group Limited | Administrative & support | 2015 |
| Cuddleco Limited | Administrative & support | 2011 |
| Cuddlepuss Ltd | Other services | 2018 |
| Cuddles Cloud Limited | Wholesale & retail | 2025 |
| Cudot Architecture Ltd | Administrative & support | 2017 |
| Cudova Investments Ltd | Wholesale & retail | 2022 |
| CUE Club 147 Limited | Arts & recreation | 2026 |
| Cuebix Ltd | Wholesale & retail | 2025 |
| Cuefin Ltd | Financial services | 2014 |
| Cugini Pizza Ltd | Hospitality | 2021 |
| Cuibo (York) Limited | Wholesale & retail | 2017 |
| Cuibonollc Ltd | Wholesale & retail | 2025 |
| Cuidadosag Limited | Real estate | 2021 |
| Cuilcagh and Co UK Limited | Arts & recreation | 2022 |
| Culcheth Property Services Limited | Real estate | 2006 |
| Culinacraft Limited | Wholesale & retail | 2026 |
| Culinary Creations NW Ltd | Hospitality | 2024 |
| Culinary Sensation Limited | Hospitality | 2021 |
| Culkeel Properties Ltd | Real estate | 2022 |
| Cull Paperless Solutions Ltd | Administrative & support | 2012 |
| Culleton Property Limited | Households | 2016 |
| Culmstock Limited | Extraterritorial | 1975 |
| Culross Avenue Residents Association Limited | Households | 2001 |
| Cult Barbers Ltd | Other services | 2017 |
| Cultplex MCR Ltd | Arts & recreation | 2023 |
| Cultrd Ltd | Professional & scientific | 2025 |
| Culturalist Ltd | Professional & scientific | 2025 |
| Culture Box Take Away Ltd | Hospitality | 2024 |
| Culture Cafe Limited | Hospitality | 2019 |
| Culture Entanglement Ltd | Professional & scientific | 2021 |
| Culture Impact Limited | Professional & scientific | 2006 |
| Culture Junction CIC | Education | 2025 |
| Culture Unites CIC | Education | 2026 |
| Cultureai Ltd | Information & communication | 2015 |
| Cultured Arts Ltd | Hospitality | 2024 |
| Cultured Clothing Ltd | Wholesale & retail | 2025 |
| Culturenova Limited | Professional & scientific | 2026 |
| Cultureshift Communications Ltd | Education | 2018 |
| Cultureshift EBT Limited | Extraterritorial | 2021 |
| Cultus Ltd | Transport & logistics | 2024 |
| Culverheys Ltd | Construction | 2021 |
| Cuma & Selahettin Okay for Trading Ltd | Other services | 2021 |
| Cumberland Close Management Company Ltd | Households | 2024 |
| Cumbernauld Investments Limited | Real estate | 2024 |
| Cumbernauld Properties Limited | Financial services | 2024 |
| Cumbernauld Services Limited | Real estate | 2025 |
| Cumbria Boiler Care Limited | Construction | 2013 |
| Cumbria Film Studios Ltd | Information & communication | 2015 |
| Cumbria Real Estates (NO 1) Ltd | Other services | 2021 |
| Cumbria Real Estates (NO 2) Ltd | Other services | 2021 |
| Cumbrian Ltd | Hospitality | 2018 |
| Cumbrian Projects Limited | Real estate | 2021 |
| Cumbrian Stores Limited | Real estate | 2021 |
| Cumulus Communications Ltd | Wholesale & retail | 2024 |
| Cuncarr Cliff Services Limited | Agriculture & fishing | 2025 |
| Cundle's Properties Ltd | Real estate | 2021 |
| Cunliffe Consultancy Ltd | Administrative & support | 2024 |
| Cunningham Consulting Ltd | Professional & scientific | 2026 |
| Cunningham Property Consultants Ltd | Professional & scientific | 2008 |
| Cunningham Ruby Consulting Limited | Professional & scientific | 2010 |
| Cunninghams Lythgoe Caplin Limited | Professional & scientific | 2013 |
| CUP & Crumb Ellenbrook Limited | Hospitality | 2024 |
| CUP IT & Co Ltd | Hospitality | 2025 |
| Cupcake Grotto Limited | Hospitality | 2014 |
| Cupcake Kingdom Ltd | Manufacturing | 2024 |
| Cupid Investment & Properties Ltd | Real estate | 2020 |
| Cuppa Candle Ltd | Wholesale & retail | 2020 |
| Cuppa Chaii (Fallowfield) Ltd | Hospitality | 2024 |
| Cuppa Coffee Limited | Hospitality | 2024 |
| Cuppello's Company Lymm Limited | Hospitality | 2023 |
| Cuprum Electrical Limited | Construction | 2019 |
| Cupule Holdings Limited | Financial services | 2024 |
| Cura Travel Management Limited | Administrative & support | 2025 |
| Curacorn International Ltd | Education | 2025 |
| Curacorn Limited | Education | 2023 |
| Curatebox Ltd | Information & communication | 2025 |
| Curated Place Ltd | Professional & scientific | 2011 |
| Curated Psychology Ltd | Professional & scientific | 2024 |
| Curatis Limited | Other services | 2023 |
| Curatum Social Care Consultancy Limited | Public administration | 2024 |
| Curby Ltd | Wholesale & retail | 2025 |
| Cure Bridge Ltd | Health & social care | 2025 |
| Cure Expert Ltd | Health & social care | 2026 |
| Cure Natural Ltd | Extraterritorial | 2022 |
| Curentu Ltd | Wholesale & retail | 2022 |
| Curin Ltd | Wholesale & retail | 2021 |
| Curio Bidco Limited | Financial services | 2024 |
| Curio Midco Limited | Financial services | 2024 |
| Curio Topco Limited | Financial services | 2024 |
| Curiosity Project MCR C.I.C. | Health & social care | 2025 |