| Connexai Software Ltd | Information & communication | 2023 |
| Connexo Limited | Wholesale & retail | 2026 |
| Connie Personal Shopping Ltd | Wholesale & retail | 2022 |
| Connie’S Closet Limited | Wholesale & retail | 2022 |
| Conning Computer Limited | Information & communication | 2025 |
| CONNOISSEURS2026 Ltd | Wholesale & retail | 2026 |
| Connolly and Mannion Limited | | 1969 |
| Connolly Property Group Ltd | Real estate | 2025 |
| Connor Electrical Installation and Service Limited | Construction | 2020 |
| Connor Investment Group Ltd | Real estate | 2020 |
| Connor Mechanical Limited | Construction | 2022 |
| Connor Properties Limited | Real estate | 2015 |
| Connor Property Management Ltd | Real estate | 2011 |
| Connova Group Limited | Administrative & support | 2019 |
| Conor Drum Ltd | Wholesale & retail | 2025 |
| Conor Heaney Publishing Limited | Information & communication | 2014 |
| Conqolx Technologies Limited | Wholesale & retail | 2023 |
| Conquest: Cradle DU Codes Limited | Information & communication | 2012 |
| Conrad Capital Limited | Real estate | 2017 |
| Conrad Real Estate Development Ltd | Real estate | 2024 |
| Conradie Ltd | Professional & scientific | 2022 |
| Conran Properties Limited | Real estate | 2013 |
| Conrise for International Trading Ltd | Wholesale & retail | 2025 |
| Conroy MD Limited | Health & social care | 2021 |
| Conscious Contemplation Limited | Health & social care | 2025 |
| Consent KIT Ltd | Information & communication | 2019 |
| Conserv Global Limited | Health & social care | 2018 |
| Conservation, Heritage, Restoration & Building Limited | Information & communication | 2020 |
| Conservatory Insulations Northwest Limited | Construction | 2015 |
| Consetec Holding Ltd | Extraterritorial | 2023 |
| Consilio Group Limited | Professional & scientific | 2024 |
| Consilium Academies | Education | 2015 |
| Consilium Cras Ltd | Real estate | 2024 |
| Consilium Life Ltd | Education | 2025 |
| Consistence Services Ltd | Health & social care | 2022 |
| Consistent Education Limited | Education | 2020 |
| Conskills Limited | Other services | 2017 |
| Console Trading Ltd | Wholesale & retail | 2017 |
| Consolia Ltd | Professional & scientific | 2006 |
| Consolidated African Ventures (UK) Limited | Real estate | 2003 |
| Consolidated Investment Holdings Limited | Professional & scientific | 2005 |
| Consolidated Petroleum Company Limited(The) | Professional & scientific | 1928 |
| Consolidated Petroleum Supply Company Limited(The) | Professional & scientific | 1960 |
| Consolidated Pumps (U.K.) Limited | Administrative & support | 2001 |
| Consolidated Textile Ltd | Wholesale & retail | 2018 |
| Consolux M&E Consulting Ltd | Professional & scientific | 1996 |
| Consonnant Ltd | Professional & scientific | 2021 |
| Consort Road Property Limited | Real estate | 2022 |
| Consortius Solutions Limited | Financial services | 2022 |
| Constable House Management Company Limited | Households | 2002 |
| Constant Healthcare Services Limited | Administrative & support | 2023 |
| Constant Power Limited | Construction | 2020 |
| Constantin Properties Ltd | Real estate | 2021 |
| Constata Ltd | Professional & scientific | 2017 |
| Constellation Genomics Ltd | Information & communication | 2024 |
| Constellation Living Ltd | Real estate | 2024 |
| Constrology Ltd | Construction | 2026 |
| Construct Catering Ltd | Hospitality | 2017 |
| Construct Sense Limited | Administrative & support | 2007 |
| Construct U.K. Limited | Wholesale & retail | 2002 |
| Construct-Cds Ltd | Construction | 2016 |
| Constructcity.Co.Uk Limited | Construction | 2023 |
| Constructicon Limited | Construction | 2003 |
| Constructing & Arcitecture Ltd | Administrative & support | 2024 |
| Construction & Fixing Ltd | Construction | 2012 |
| Construction Advisory Associates Limited | Professional & scientific | 2014 |
| Construction and Fit OUT Limited | Construction | 2016 |
| Construction and Property Solutions Ltd | Administrative & support | 2011 |
| Construction Assist Services Ltd | Professional & scientific | 2020 |
| Construction Camel Ltd | Real estate | 2024 |
| Construction CC Limited | Construction | 2021 |
| Construction Commercial Management Consultancy Ltd | Administrative & support | 2016 |
| Construction Connectz Ltd | Construction | 2025 |
| Construction Covered Ltd | Construction | 2023 |
| Construction Design Pro Ltd | Construction | 2021 |
| Construction Dispute Services Limited | Professional & scientific | 2020 |
| Construction for Women CIC | Education | 2024 |
| Construction Icon for Trade and General Contracting Ltd | Construction | 2025 |
| Construction Media Limited | Information & communication | 2023 |
| Construction Nvqs Ltd | Education | 2024 |
| Construction on Site Consultancy Ltd | Professional & scientific | 2017 |
| Construction Partnership UK Limited | Construction | 2000 |
| Construction Point Limited | Construction | 2024 |
| Construction POP Ltd | Construction | 2023 |
| Construction Recruitment Solutions (North) Limited | Administrative & support | 2025 |
| Construction Risk Solutions Ltd | Extraterritorial | 2021 |
| Construction Site Validation Services Ltd | Professional & scientific | 2024 |
| Construction Solutions (North West) Holdings Ltd | Financial services | 2023 |
| Construction Solutions (North West) Limited | Construction | 2016 |
| Construction Technical Services by Day Limited | Professional & scientific | 2019 |
| Construction Tops Company Ltd | Construction | 2025 |
| Construction Training Development Ltd | Professional & scientific | 2025 |
| Construction Zombie Limited | Construction | 2025 |
| Constructionhelpdesk PVT Ltd | Professional & scientific | 2020 |
| Constructionuk Ltd | Construction | 2026 |
| Consulate Bramhall Limited | Households | 2016 |
| Consult Decision Manager Ltd | Information & communication | 2025 |
| Consult Integrated Solutions C.I.C. | Professional & scientific | 2024 |
| Consult MEN Limited | Wholesale & retail | 2024 |
| Consult Tilt Limited | Information & communication | 2020 |