| CLF Distribution & Partners Limited | Administrative & support | 2021 |
| CLF Distribution Limited | Wholesale & retail | 1998 |
| CLG Consulting Ltd | Agriculture & fishing | 2024 |
| CLI Logistics Ltd | Transport & logistics | 2019 |
| Click Information Terminology Limited | Administrative & support | 1995 |
| Click N Van Ltd | Administrative & support | 2025 |
| Click Property Investment Ltd | Real estate | 2023 |
| CLICK2PICKS Limited | Wholesale & retail | 2021 |
| Clickavate Ltd | Information & communication | 2025 |
| Clickbait Media Limited | Information & communication | 2025 |
| Clicknexus UK Ltd | Wholesale & retail | 2025 |
| Clientflow Ltd | Information & communication | 2023 |
| Cliff ROE Sports Limited | Wholesale & retail | 2005 |
| Clifford Cars Limited | Transport & logistics | 2021 |
| Clifford Catering Management Limited | Professional & scientific | 2015 |
| Clifford EYE Health Limited | Health & social care | 2014 |
| Clifton Court Management (Southampton) Limited | Households | 1998 |
| Clifton Maintenance Services Ltd | Construction | 2025 |
| Climate Change Services Ltd | Construction | 2020 |
| Climate Essentials Limited | Information & communication | 2019 |
| Climate GAS Ltd | Construction | 2012 |
| Clinic Fitouts Limited | Construction | 2025 |
| Clinic Marketing Consulting Company Ltd | Professional & scientific | 2025 |
| Clinical Cosmetics Aesthetics Ltd | Health & social care | 2019 |
| Clinical Enterprise Limited | Health & social care | 2014 |
| Clinical Oncology Services Limited | Health & social care | 2016 |
| Clinique Allure Ltd | Other services | 2019 |
| Clink & Drink Mobile Bars Limited | Hospitality | 2022 |
| Clinova Limited | Wholesale & retail | 2006 |
| Clipper&Guy Barbers Limited | Other services | 2021 |
| Cliqhealth Ltd | Hospitality | 2025 |
| Clive Dibden Plant Hire Limited | Agriculture & fishing | 1986 |
| CLJ Marketing and Consulting Limited | Professional & scientific | 2022 |
| CLK IT Consulting Ltd | Information & communication | 2016 |
| Clogged Limited | Administrative & support | 2024 |
| Cloner Film Limited | Information & communication | 2024 |
| Closeiq Ltd | Other services | 2025 |
| Clothes 1 Pound Ltd | Wholesale & retail | 2023 |
| Clothiers Composites Ltd | Manufacturing | 2025 |
| CLOU9 Design Limited | Information & communication | 2015 |
| Cloud 8 Limited | Information & communication | 2019 |
| Cloud 9 Lettings Ltd | Other services | 2020 |
| Cloud Barbers Ltd | Other services | 2025 |
| Cloud Data Experts Limited | Professional & scientific | 2015 |
| Cloud Hawk Tech Limited | Wholesale & retail | 2023 |
| Cloud Nine HQ Ltd | Other services | 2020 |
| Cloud People Recruitment Ltd | Administrative & support | 2022 |
| Cloudbaseholdings Limited | Real estate | 2023 |
| Clouder Holdings Ltd | Financial services | 2026 |
| Clouder Properties Ltd | Real estate | 2026 |
| Cloudficient Solutions Ltd | Information & communication | 2020 |
| Cloudqueror Incorporated Limited | Professional & scientific | 2025 |
| Cloudreach Consultancy Limited | Information & communication | 2025 |
| Clouds Shisha Limited | Hospitality | 2018 |
| Cloudtour Limited | Extraterritorial | 2014 |
| Cloupium Consulting Limited | Information & communication | 2019 |
| Clover Family Cover Ltd | Financial services | 2018 |
| Clover Financial Solutions Limited | Financial services | 2008 |
| Clover Healthcare Solutions Ltd | Administrative & support | 2015 |
| Clover Practice Limited | Health & social care | 2010 |
| Cloverfield Park Limited | Construction | 2016 |
| Cloverwest Group Limited | Financial services | 2026 |
| Cloverwest Investments Limited | Financial services | 2026 |
| Cloverwest Solutions Limited | Professional & scientific | 2025 |
| Clowder Green Ltd | Construction | 2019 |
| Club House Catering 19 Ltd | Hospitality | 2024 |
| Club Pace Limited | Arts & recreation | 2025 |
| Cluricaun Ltd | Professional & scientific | 2012 |
| Clydeborne Solutions Limited | Wholesale & retail | 2025 |
| Clydesdale Group Limited | Construction | 2009 |
| Clydesdale Properties Limited | Real estate | 2013 |
| CM & E Investments Limited | Health & social care | 2021 |
| CM Anozie Limited | Health & social care | 2021 |
| CM Beasy Limited | Information & communication | 1984 |
| CM Carter Joinery Limited | Construction | 2018 |
| CM Elite Sports Management Ltd | Professional & scientific | 2025 |
| CM Mechanical Fitting Services Ltd | Manufacturing | 2018 |
| CM Phillips Carpentry & Joinery Ltd | Manufacturing | 2016 |
| CM Psych Services Ltd | Other services | 2023 |
| CM Sales Ltd | Wholesale & retail | 2020 |
| CM Supported Living Services Limited | Health & social care | 2018 |
| CM2L Limited | Professional & scientific | 2017 |
| CMA Financial Recruitment Limited | Administrative & support | 2006 |
| CMA Financial Temps Limited | Extraterritorial | 1997 |
| Cmck Consulting Ltd | Professional & scientific | 2026 |
| Cmetal Holdings Ltd | Professional & scientific | 2022 |
| Cmetal Investments Ltd | Professional & scientific | 2022 |
| CMF Technical Services Ltd | Administrative & support | 2025 |
| Cmlogisticsuk Ltd | Transport & logistics | 2025 |
| CMM Data Solutions LLP | | 2018 |
| CMR Lettings Ltd | Real estate | 2018 |
| CMV Trans Limited | Transport & logistics | 2023 |
| Cmwrepairs Ltd | Construction | 2023 |
| CN Industries Ltd | Construction | 2025 |
| Cnl.Jj.Entertainment Ltd | Arts & recreation | 2025 |
| Cnnmn Industries Ltd | Information & communication | 2025 |
| CNS Networks Ltd | Administrative & support | 2016 |
| Cnxtrans Ltd | Transport & logistics | 2025 |
| Co Sushi Limited | Hospitality | 2018 |
| Co.Shelf TEN Limited | Information & communication | 1997 |