| Cross & Last Holdings Ltd | Manufacturing | 2025 |
| Cross Keys Wymondham Limited | Hospitality | 2018 |
| Cross-Border Worldwide Ltd | Professional & scientific | 2022 |
| Crossbreed Studios Ltd | Information & communication | 2025 |
| Crossfire Performance Ltd | Arts & recreation | 2024 |
| Crosskills (P.E.) Limited | Wholesale & retail | 1984 |
| Crossley Holdings Ltd | Financial services | 2018 |
| Crossley Investment Holdings Ltd | Financial services | 2021 |
| Crossover Security Limited | Administrative & support | 2013 |
| Crossroads London Ltd | Hospitality | 2021 |
| Crosstones Ltd | Construction | 2025 |
| Crostwick Holdings Limited | Administrative & support | 1980 |
| Crow Temple Tattoo Ltd | Arts & recreation | 2019 |
| Crowfoot Ltd | Construction | 2026 |
| Crowheart Productions Ltd | Information & communication | 2020 |
| Crowley Consultancy Limited | Professional & scientific | 2024 |
| Crown & Clover Property Ltd | Real estate | 2023 |
| Crown Chicken Norwich Limited | Hospitality | 2019 |
| Crown Cleaning Group Ltd | Administrative & support | 2016 |
| Crown Commodities and Consumables Ltd | Wholesale & retail | 2017 |
| Crown Costessey Limited | Hospitality | 2019 |
| Crown Court Yard (Kenninghall) Management Company Limited | Households | 2006 |
| Crown Harmony Property Limited | Hospitality | 2025 |
| Crown Management (UK) Ltd. | Real estate | 2007 |
| Crown Place Management (Diss) Ltd | Households | 2015 |
| Crown Point Cuisine (Norwich) Limited | Hospitality | 2024 |
| Crown Supplies Limited | Wholesale & retail | 1994 |
| Crownbay Limited | Extraterritorial | 2022 |
| Crowned Jewels Limited | Manufacturing | 2008 |
| Crownthorpe Consulting Ltd | Real estate | 2024 |
| Crowstone Manor Limited | Health & social care | 2014 |
| Croylands Holiday Hideaways Limited | Hospitality | 2023 |
| CRP (U.K.) Ltd | Arts & recreation | 2016 |
| CRS Investments Ltd | Real estate | 2020 |
| Cruickshank Holdings Ltd | Financial services | 2023 |
| Cruisea Ltd | Administrative & support | 2026 |
| Crumb Norwich Ltd | Hospitality | 2026 |
| Crumpetorium Limited | Manufacturing | 2021 |
| Crush Foods Ltd | Manufacturing | 2011 |
| Crusts and Crumbs Ltd | Hospitality | 2022 |
| Crux Business Consulting Limited | Professional & scientific | 2016 |
| Cruzado Limited | Health & social care | 2010 |
| Crypto Brill Ltd | Professional & scientific | 2024 |
| Crystal & Fran Ltd | Real estate | 2021 |
| Crystal Clear Cleaning Co (AL) Limited | Administrative & support | 2020 |
| Crystal Design & Media Ltd | Information & communication | 2011 |
| Crystal Fish Bar Ltd | Hospitality | 2023 |
| Crystal Multinational Ltd | Transport & logistics | 2026 |
| Crystal Palace Motor Company Limited | Wholesale & retail | 2020 |
| Crystal Planet TB Limited | Wholesale & retail | 2026 |
| CS Group UK Holdings Limited | Financial services | 2024 |
| CS Media Production Limited | Information & communication | 2022 |
| CS Synergy Services Ltd | Administrative & support | 2026 |
| CS Upholsterers Ltd | Wholesale & retail | 2026 |
| CS2 Retail Limited | Extraterritorial | 2017 |
| CS3 Consultancy Ltd | Real estate | 2024 |
| CS3 Properties Ltd | Real estate | 2017 |
| Csales Limited | Wholesale & retail | 2022 |
| CSB EA Ltd | Other services | 2024 |
| CSB Rentals 2 Ltd | Real estate | 2024 |
| CSB Rentals Ltd | Real estate | 2023 |
| CSH EA Ltd | Other services | 2024 |
| CSH Services Limited | Extraterritorial | 2021 |
| CSN Group Midlands Ltd | Hospitality | 2018 |
| Csnl Holdings Ltd | Financial services | 2020 |
| CSO Heating Limited | Energy | 2015 |
| CSP Elite Limited | Real estate | 2025 |
| CSR Planning Limited | Financial services | 2012 |
| CSR Waste Management Limited | Water & waste | 2026 |
| Csrai Ltd | Health & social care | 2021 |
| CSS Investment Holdings Limited | Real estate | 1985 |
| CSTAN2022 Limited | Transport & logistics | 2022 |
| CT Capital Limited | Financial services | 1987 |
| CT Catering Ltd | Hospitality | 2020 |
| CT INS Consultants Ltd | Financial services | 2022 |
| CTA Investments Ltd | Real estate | 2017 |
| CTB Home Improvements Limited | Construction | 2021 |
| CTI Offshore Services Ltd | Professional & scientific | 2021 |
| CTM (Colour Tool Management) Limited | Professional & scientific | 2003 |
| CTP Carpets Limited | Construction | 2016 |
| CTR Secure Services EOT Limited | Administrative & support | 2023 |
| CTR Secure Services Ltd | Administrative & support | 2003 |
| CTR Services Holdings Limited | Financial services | 2022 |
| Ctrl AI Global Ltd | Information & communication | 2024 |
| Ctrl AI Ltd | Information & communication | 2024 |
| Cube Connection Limited | Information & communication | 1993 |
| Cube Install Ltd | Construction | 2016 |
| Cube Project Consultants Limited | Construction | 2003 |
| Cubic Engineering Limited | Wholesale & retail | 2005 |
| Cucci Rite Care Ltd | Health & social care | 2019 |
| Cuckoo Films Limited | Information & communication | 2007 |
| Cuckoo Ventures Ltd | Wholesale & retail | 2021 |
| Cucumkin Limited | Administrative & support | 2024 |
| Cullington Electrical Ltd | Administrative & support | 2003 |
| Cullington Property Limited | Real estate | 2023 |
| Cullompton Dining Ltd | Hospitality | 2019 |
| Cullum Line Limited | Construction | 2020 |
| Cullum Property Services Ltd | Manufacturing | 2007 |
| Cullum's Commercials Limited | Wholesale & retail | 2019 |
| Cullumbine Limited | Professional & scientific | 2021 |