| Crison Ltd | Construction | 2024 |
| Crispo Ltd | Construction | 2019 |
| Crispy Duck Technical Production Ltd | Information & communication | 2023 |
| Cristee Health Care Limited | Health & social care | 2016 |
| Cristi Andrei Trans Ltd | Transport & logistics | 2019 |
| Cristi NEGRAN95 Limited | Transport & logistics | 2019 |
| Cristi Trans Ltd | Transport & logistics | 2020 |
| Cristian Sameday Limited | Transport & logistics | 2024 |
| Cristiblue Ltd | Transport & logistics | 2017 |
| Cristo's TM Ltd | Public administration | 2021 |
| Cristy@Tiffany Limited | Health & social care | 2022 |
| Crng Ltd | Hospitality | 2024 |
| Croft 1964 Limited | Extraterritorial | 2013 |
| Croft Industrial Boiler Services Limited | Manufacturing | 2021 |
| Croftsdun Enterprises Limited | Real estate | 1966 |
| Crompton Rail Ltd | Construction | 2024 |
| Crooked Cynics Limited | Information & communication | 2014 |
| Crossbank Holdings Limited | Professional & scientific | 1995 |
| Crossco (1370) Limited | Water & waste | 2014 |
| Crossco (1371) Limited | Water & waste | 2014 |
| Crossgate Parking Limited | Other services | 2022 |
| Crosshills Fisheries Limited | Hospitality | 2013 |
| Crossjin Limited | Professional & scientific | 2007 |
| Crosswait Ltd | Information & communication | 2025 |
| Crown & Ledger Property Ltd | Extraterritorial | 2026 |
| Crown Bawtry Property Group Ltd | Real estate | 2021 |
| Crown Bawtry Property Ltd | Real estate | 2018 |
| Crown Defence Security Ltd | Administrative & support | 2024 |
| Crown Door Systems Limited | Manufacturing | 2025 |
| Crown Hotel Holdings Limited | Hospitality | 2017 |
| Crown Landscaping Ltd | Administrative & support | 2019 |
| Crown Roofing (Yorks) Ltd | Construction | 2024 |
| Crown Shares Ltd | Financial services | 2026 |
| Crownspire Technologies Ltd | Extraterritorial | 2026 |
| Crownstone Brick Ltd | Extraterritorial | 2026 |
| Crowsgarth Ltd | Other services | 2021 |
| Crozier Jones Associates Limited | Professional & scientific | 1992 |
| Crozier Jones LLP | | 2012 |
| Crucial Skills Limited | Administrative & support | 2009 |
| Cruelty Free Vegan C.I.C. | Wholesale & retail | 2018 |
| Cryo 1 Limited | Health & social care | 2017 |
| Cryptix Limited | Financial services | 2022 |
| Cryptocurrency Ltd | Extraterritorial | 2019 |
| Cryptonix Limited | Hospitality | 2025 |
| Crystal Car Luxury Valeting & Detailing Ltd | Wholesale & retail | 2025 |
| Crystal Clean Launderette Ltd | Other services | 2025 |
| Crystal Clear Cleaning Solutions Limited | Administrative & support | 2025 |
| Crystal Property Investments 28 Limited | Real estate | 2024 |
| Crystalclear Locks Ltd | Information & communication | 2023 |
| CS Construction (Doncaster) Limited | Construction | 2025 |
| CS Haulage Ltd | Transport & logistics | 2024 |
| CS Star Holdings Ltd | Real estate | 2026 |
| CSC Engineering Services Ltd | Professional & scientific | 2021 |
| Cscs Services Ltd | Wholesale & retail | 2016 |
| CSD Productions Limited | Professional & scientific | 2018 |
| CSH Accounting Limited | Professional & scientific | 2019 |
| CSL Accountancy Services Ltd | Professional & scientific | 2025 |
| CSL Data Services Limited | Information & communication | 2017 |
| CSS Joinery Ltd | Administrative & support | 2017 |
| CSS PAY Limited | Administrative & support | 2017 |
| Csta Global Limited | Professional & scientific | 2018 |
| CT Consultancy Process Improvement Limited | Professional & scientific | 2025 |
| CT Plant Repairs Ltd | Manufacturing | 2019 |
| CTC Consulting Limited | Professional & scientific | 2025 |
| CTD Transport Ltd | Transport & logistics | 2018 |
| Ctib Property Limited | Real estate | 2025 |
| CTT Repair and Maintenance Ltd | Manufacturing | 2022 |
| CU Forms Ltd | Information & communication | 2019 |
| Cubbin & Co Ltd | Professional & scientific | 2021 |
| Cuckoo Brands Ltd | Manufacturing | 2019 |
| Cuckoo Leisure Ltd | Hospitality | 2019 |
| Cuddle Pups Ltd | Wholesale & retail | 2025 |
| Cullens Estates Ltd | Real estate | 2025 |
| Cullhaj Couriers Ltd | Transport & logistics | 2023 |
| Cumbria Land Management (Flusco) Limited | Financial services | 2024 |
| Cumbria Land Management (Teeside) Ltd | Financial services | 2024 |
| Cumbria Waste Management Ltd. | Water & waste | 1991 |
| Cumbria Waste Recycling Limited | Water & waste | 1996 |
| Cumbria Wildlife Park Ltd | Arts & recreation | 2025 |
| Cunningham Management Services Limited | Professional & scientific | 2023 |
| Cupcakes 2 Love Ltd | Wholesale & retail | 2012 |
| Cupphon Ltd | Wholesale & retail | 2026 |
| Cura Compliance UK Limited | Transport & logistics | 2024 |
| Cura Health Clinic Limited | Health & social care | 2023 |
| Cura Products Limited | Wholesale & retail | 2014 |
| Cura-Care Community C.I.C. | Administrative & support | 2023 |
| Cura-Care Yorkshire Ltd | Health & social care | 2017 |
| Curate Technology Limited | Information & communication | 2025 |
| Curlévo Haircare Limited | Manufacturing | 2025 |
| Curry Leaf Indian Restaurant Limited | Hospitality | 2014 |
| Curry Leaf Restaurant Ltd | Hospitality | 2026 |
| Cursaru Ltd | Transport & logistics | 2021 |
| Cursorpro Ltd | Professional & scientific | 2016 |
| Curtis Campers Limited | Wholesale & retail | 2022 |
| Curvus Bespoke Wooden Products Ltd | Manufacturing | 2020 |
| Cusack Limited | Wholesale & retail | 2025 |
| Custom Component Engineering Ltd | Manufacturing | 2016 |
| Custom Gates Ltd | Manufacturing | 2021 |
| Custom Made Kitchens Holdings Limited | Financial services | 2007 |
| Custom Made Kitchens Limited | Manufacturing | 1990 |