| Crown House (Walkley) RTM Company Limited | Real estate | 2019 |
| Crown Investments (South Yorkshire) Limited | Real estate | 2007 |
| Crown Motor Co (Bawtry) Ltd | Wholesale & retail | 2023 |
| Crown Property Investor Ltd | Construction | 2023 |
| Crown Ranet Ltd | Wholesale & retail | 2020 |
| Crown Skin Clinic UK Ltd | Health & social care | 2026 |
| Crowned Collective Co Limited | Wholesale & retail | 2025 |
| Crownholme Limited | Construction | 1997 |
| Crownmark Beverages Ltd | Wholesale & retail | 2025 |
| Crowntransfer Ltd | Wholesale & retail | 2020 |
| Crowston Contractors Limited | Wholesale & retail | 2004 |
| Crowther Interiors Ltd | Professional & scientific | 2020 |
| Crowther Stevens Limited | Real estate | 2026 |
| Croydon Self-Store Ltd | Administrative & support | 2007 |
| CRS Accounting Services Ltd | Professional & scientific | 2020 |
| CRS PUB Co Ltd | Hospitality | 2025 |
| Crse Limited | Arts & recreation | 2024 |
| CRU Contracts Limited | Wholesale & retail | 2003 |
| Crucial Fire & Security Ltd | Public administration | 2024 |
| Crucial Solutions (NE) Limited | Construction | 2018 |
| Crucible Associates Limited | Information & communication | 2021 |
| Crucible Capital Limited | Financial services | 2023 |
| Crucible Co-Operative Learning Trust | Education | 2016 |
| Crucible Gaming Ltd | Arts & recreation | 2022 |
| Crucible Goods Limited | Wholesale & retail | 2026 |
| Crucible Limited | Extraterritorial | 2014 |
| Crucible Motors Ltd | Wholesale & retail | 2019 |
| Crucible Partners Limited | Real estate | 2021 |
| Crucible Performance Management Limited | Administrative & support | 2007 |
| Crucible Pharmacy Limited | Wholesale & retail | 2023 |
| Crucible Project Management Limited | Professional & scientific | 2022 |
| Crucible Properties Ltd | Real estate | 2019 |
| Crucible Recruitment Limited | Administrative & support | 2016 |
| Crucible Software Ltd | Information & communication | 2019 |
| Crucible Therapeutics Limited | Professional & scientific | 2023 |
| Crucibleai Ltd | Information & communication | 2026 |
| Cruiseholidays.Co.Uk Ltd | Professional & scientific | 2011 |
| Cruisepal UK Limited | Information & communication | 2003 |
| Crumbs Bakery (Sheffield) Ltd | Manufacturing | 2015 |
| Crumbs Broomhill Ltd | Hospitality | 2024 |
| Crumcorp Ltd | Professional & scientific | 2020 |
| Crump Holdings Ltd | Financial services | 2020 |
| Crump Properties Ltd | Real estate | 2020 |
| Crunch N Roll Ltd | Information & communication | 2021 |
| Crunch Sort UK Limited | Wholesale & retail | 2025 |
| Crusade Part Solutions Ltd | Wholesale & retail | 2026 |
| Cruz Band Ltd | Information & communication | 2025 |
| CRV Homes Limited | Real estate | 2016 |
| Cryo Padana Limited | Other services | 2016 |
| Cryo Sports Development Ltd | Education | 2025 |
| Cryo Technologies Ltd | Manufacturing | 2022 |
| Cryo Wellness & Holistics Ltd | Health & social care | 2019 |
| Cryoroc Limited | Administrative & support | 2012 |
| Cryoserve Engineering Services Limited | Professional & scientific | 2020 |
| Cryptid Queers Ltd | Wholesale & retail | 2026 |
| Crystal 360 Limited | Arts & recreation | 2017 |
| Crystal Clean Bridal Ltd | Households | 2024 |
| Crystal Clear 1ST AID Training Ltd | Education | 2011 |
| Crystal Clear Ice Solutions Ltd | Administrative & support | 2026 |
| Crystal Clear Windows (Yorkshire) Ltd | Construction | 2012 |
| Crystal Conservatories Ltd | Construction | 2022 |
| Crystal Equine Ltd | Wholesale & retail | 2025 |
| Crystal Fast Food Limited | Hospitality | 2021 |
| Crystal Gents Barber Ltd | Other services | 2026 |
| Crystal Klean Ltd | Administrative & support | 2022 |
| Crystal Klear Ltd | Hospitality | 2025 |
| Crystal Nail Salon Ltd | Other services | 2015 |
| Crystal Nails 505 Limited | Other services | 2024 |
| Crystal Prime UK Limited | Wholesale & retail | 2024 |
| Crystal Ship Limited | Administrative & support | 2010 |
| Crystal Ship Productions Limited | Information & communication | 2016 |
| Crystal Ship Vehicles Limited | Administrative & support | 2019 |
| CRÜ Solutions Ltd | Information & communication | 2025 |
| CS Commercial Cleaning Ltd | Administrative & support | 2025 |
| CS Community Coaching CIC | Arts & recreation | 2024 |
| CS Flat Roofing Limited | Construction | 2025 |
| CS Funfairs Ltd | Administrative & support | 2025 |
| CS Secure Limited | Information & communication | 2025 |
| CS Surveying and Architectural Design Limited | Professional & scientific | 2004 |
| CS UK Cleaning Services Ltd | Administrative & support | 2020 |
| CSA Physiotherapy Ltd | Health & social care | 2021 |
| Csaba Zsakai Ltd | Construction | 2018 |
| CSC Freehold Limited | Real estate | 2010 |
| Csevans Consultancy Limited | Professional & scientific | 2022 |
| CSF Services Limited | Information & communication | 2015 |
| CSH Hvac Services Ltd | Construction | 2016 |
| CSI Leasing Europe Limited | Financial services | 2014 |
| CSM Carpets & Flooring Ltd | Construction | 2001 |
| CSM Investments Limited | Financial services | 2018 |
| Csmj Leisure Limited | Hospitality | 2024 |
| Csms Print Solutions Limited | Wholesale & retail | 2005 |
| CSR Project Solutions Limited | Information & communication | 2025 |
| CT GAS Services Ltd | Construction | 2023 |
| Ct-Consultancy SP Limited | Information & communication | 2026 |
| CT24-7 Limited | Transport & logistics | 2019 |
| Ctab Limited | Information & communication | 2024 |
| CTG Cognizance Ltd | Professional & scientific | 2025 |
| CTG Utilities Limited | Construction | 2015 |
| Cthru Smiles Limited | Extraterritorial | 2018 |
| CTM Sports Ltd | Other services | 2008 |