| Clicked Skills Ltd | Information & communication | 2024 |
| Clickhaven Ltd | Wholesale & retail | 2025 |
| Clickrigging Ltd | Manufacturing | 2019 |
| Clicks PAY Limited | Administrative & support | 2018 |
| Clicksell Property Ltd | Information & communication | 2026 |
| Clicksphare Craft Ltd | Wholesale & retail | 2025 |
| Clickstream Ltd | Wholesale & retail | 2025 |
| Clicktop Ltd | Other services | 2025 |
| Client Accounts Services Ltd | Professional & scientific | 2026 |
| Client Driven Solutions UK Ltd | Information & communication | 2018 |
| Cliff Edge Pictures Limited | Information & communication | 2015 |
| Cliff Holme Ltd | Wholesale & retail | 2023 |
| Cliff-Edge Developments Limited | Real estate | 1998 |
| Cliffdawn Limited | Households | 1997 |
| Clifford Watts Limited | Financial services | 2012 |
| Clifton Dental Care Limited | Health & social care | 2009 |
| Clifton Hair and Cosmetics Ltd | Wholesale & retail | 2019 |
| Clifton Occupational Medical Services Ltd | Health & social care | 2018 |
| Clifton Pharmacy Limited | Wholesale & retail | 2003 |
| Clifton Store D Ltd | Wholesale & retail | 2025 |
| Cliftonkeys Ltd | Construction | 2025 |
| Cliftonto Yantley Ltd | Wholesale & retail | 2025 |
| Climac Ltd | Energy | 2022 |
| Climate Calm Ltd | Professional & scientific | 2025 |
| Climate Control Systems Ltd | Construction | 2026 |
| Climate Solutions Refrigeration and Air Conditioning Limited | Energy | 2021 |
| Climatech Infrastructure Leasing Ltd. | Financial services | 2021 |
| Climatemaps Ltd | Information & communication | 2022 |
| Climax Trend Limited | Wholesale & retail | 2022 |
| Clinic Hub 1 Ltd | Other services | 2025 |
| Clinic Link Limited | Administrative & support | 2024 |
| Clinicops Ltd | Information & communication | 2026 |
| Clinics Vera Limited | Other services | 2026 |
| Clinig Byw'N Iach Ltd | Health & social care | 2020 |
| Clinista Ltd | Health & social care | 2025 |
| Clinopex Ltd | Professional & scientific | 2023 |
| Clinton Frazer Limited | Information & communication | 2015 |
| Clio Investments Limited | Information & communication | 2021 |
| Clip Hub Limited | Information & communication | 2023 |
| Clippersail Limited | Manufacturing | 2013 |
| Clive Charles Properties Ltd | Real estate | 2018 |
| Clive Crescent Ltd | Construction | 2025 |
| Clive Gascoyne Consultancy Limited | Education | 2012 |
| Clive Livermore Limited | Construction | 2021 |
| Clive Morris Accountants Limited | Professional & scientific | 2012 |
| Clive Road Management Company Limited | Extraterritorial | 2018 |
| Clive Road Properties Ltd | Households | 2025 |
| Clive Road Stores Limited | Wholesale & retail | 2003 |
| Clive Street Management Limited | Households | 2003 |
| Clivewin Ltd | Households | 2023 |
| CLJ Properties Limited | Administrative & support | 2007 |
| CLK1 Limited | Hospitality | 2020 |
| Cllear RX Ltd | Manufacturing | 2021 |
| Cllkstor Ltd | Wholesale & retail | 2025 |
| Clmc Ltd | Administrative & support | 2024 |
| Clmw Capital Limited | Professional & scientific | 2016 |
| Cloak & Drape Ltd | Manufacturing | 2023 |
| Clock Sister Limited | Wholesale & retail | 2023 |
| Clockwork Chroming and Motorcycle Parts Limited | Wholesale & retail | 2015 |
| Clockwork Construction Limited | Construction | 2009 |
| Clockwork Contracts Limited | Real estate | 2002 |
| Clockwork Maintenance & Refurbishment Limited | Construction | 2020 |
| Cloisters Business Centre Management Company Limited | Real estate | 1987 |
| Cloo Chat Limited | Extraterritorial | 2018 |
| Clorich Limited | Real estate | 1965 |
| Clos Gwenllian Management Company Limited | Households | 2023 |
| Clos Treoda Residents Association (Cardiff) Limited | Households | 1982 |
| Close UP Arts Limited | Administrative & support | 2019 |
| Closeprotec Security Intelligence Consultancy Ltd | Extraterritorial | 2017 |
| Closers X Limited | Information & communication | 2025 |
| Closie Ltd | Wholesale & retail | 2022 |
| Cloth Cat Animation Limited | Information & communication | 2012 |
| Cloth Cat Games Limited | Information & communication | 2014 |
| Cloth Cat LBB Limited | Information & communication | 2016 |
| Cloth Cat Limited | Information & communication | 2006 |
| Clothing Ample Ltd | Manufacturing | 2025 |
| Clothingclub Limited | Wholesale & retail | 2025 |
| Cloud 360 UK Limited | Information & communication | 2021 |
| Cloud 85 Studio Ltd | Construction | 2023 |
| Cloud 9 Guitars Ltd | Manufacturing | 2022 |
| Cloud 9 Removals Limited | Transport & logistics | 2019 |
| Cloud Aero Independent Ltd | Professional & scientific | 2022 |
| Cloud Aero Ltd | Transport & logistics | 2020 |
| Cloud Aero Training Ltd | Transport & logistics | 2025 |
| Cloud BUS Digital Ltd | Information & communication | 2019 |
| Cloud Business Support Ltd | Wholesale & retail | 2019 |
| Cloud Compute Ltd | Information & communication | 2012 |
| Cloud Craft Systems Ltd | Information & communication | 2025 |
| Cloud Devops Ltd | Information & communication | 2023 |
| Cloud Mart Ltd | Wholesale & retail | 2025 |
| Cloud Nexus Hub Ltd | Information & communication | 2025 |
| Cloud Nine Cheam Village Limited | Wholesale & retail | 2014 |
| Cloud Nine Scripts Ltd | Information & communication | 2017 |
| Cloud Places Limited | Real estate | 2023 |
| Cloud Sea Culture Media Co., Ltd. | Wholesale & retail | 2024 |
| Cloud Solutions CRD Ltd | Information & communication | 2026 |
| Cloud Talk Solutions Ltd | Administrative & support | 2023 |
| Cloud Technology Partners Limited | Information & communication | 2015 |
| Cloud Way Path Ltd | Information & communication | 2025 |
| CLOUD2020 Limited | Wholesale & retail | 2011 |