| BXB Solutions Limited | Information & communication | 2024 |
| Bxta Nanotherapy Ltd | Health & social care | 2022 |
| Bxtaccelyon Group Limited | Financial services | 2026 |
| Bxtaccelyon Limited | Health & social care | 2012 |
| BY Comfort Chauffeurs Ltd | Other services | 2020 |
| BY Solutions Limited | Professional & scientific | 2014 |
| BY Victoria Aesthetics Ltd | Other services | 2026 |
| BY40GB Ltd | Wholesale & retail | 2026 |
| Bybox Networks Limited | Administrative & support | 1997 |
| BYH2OWENS Limited | Manufacturing | 2017 |
| Byrne Electrical Solutions Ltd | Construction | 2024 |
| Byrne Roofing Services Ltd | Construction | 2023 |
| Bytesize IT Services Ltd | Information & communication | 2023 |
| Bywaste Ltd | Water & waste | 2024 |
| Byways Technology Limited | Information & communication | 2017 |
| Byworld Resources Ltd | Real estate | 2026 |
| BZ Foods Limited | Hospitality | 2019 |
| C & H Build NO 1 Ltd | Construction | 2025 |
| C & K Holdings Limited | Construction | 1982 |
| C & M Plumbing and Heating Ltd | Construction | 2022 |
| C & S Harris Limited | Construction | 2002 |
| C B Chauffering Ltd | Transport & logistics | 2025 |
| C E Fagg (Engineering) Limited | Professional & scientific | 2018 |
| C G Dennis Fire Safety Services Ltd | Public administration | 2011 |
| C Gibbs Ltd | Construction | 2023 |
| C Gonzac Holdings Limited | Real estate | 2017 |
| C H Automobiles Limited | Wholesale & retail | 2018 |
| C Harsh Ltd | Transport & logistics | 2025 |
| C J Stone Plumbing & Heating Ltd | Construction | 2017 |
| C Radu & SON Ltd | Construction | 2024 |
| C V Automotive Group Ltd | Wholesale & retail | 2016 |
| C West Services Ltd | Construction | 2023 |
| C&J Fitters Ltd | Construction | 2024 |
| C&Spice Ltd | Hospitality | 2025 |
| C. R. Medical Limited | | 1986 |
| C.D.L.Construction Company Limited | Wholesale & retail | 1929 |
| C.D.S. Construction Services Limited | Manufacturing | 1976 |
| C.E.S Solutions Limited | Professional & scientific | 2022 |
| C.H. Robinson Worldwide (UK) Limited | Transport & logistics | 1978 |
| C.N.D Transpeed Ltd | Transport & logistics | 2024 |
| C2CHAI Ltd | Wholesale & retail | 2024 |
| C4U Homes Ltd | Health & social care | 2025 |
| CA Auto Finance UK Ltd | Financial services | 1992 |
| Caan & Rose Estates Ltd | Administrative & support | 2016 |
| Caan Logistics Ltd | Transport & logistics | 2018 |
| CAB Budget Plan & Hire Ltd | Transport & logistics | 2023 |
| CAB Point Cars Limited | Transport & logistics | 2015 |
| Cabana Services Ltd | Transport & logistics | 2020 |
| Cabatingan Limited | Health & social care | 2022 |
| Cabbi Taxis Ltd | Transport & logistics | 2024 |
| Cabco (Slough) Ltd | Transport & logistics | 2013 |
| Caberwell Limited | Professional & scientific | 2005 |
| Cablink Limited | Transport & logistics | 2024 |
| CAD Style Limited | Professional & scientific | 2016 |
| Cadebeck Limited | Wholesale & retail | 2020 |
| Cademy Youth Football Club Limited | Other services | 2025 |
| Cafe Green Group LDN Ltd | Hospitality | 2026 |
| Cafetap Ltd | Hospitality | 2026 |
| Cafetreatz Brad Ltd | Hospitality | 2026 |
| Cafetreatz Harrow Ltd | Hospitality | 2023 |
| Cafetreatz Ltd | Hospitality | 2012 |
| Cafetreatz Reading Ltd | Hospitality | 2013 |
| Cafetreatz Slough Ltd | Administrative & support | 2020 |
| Cafetreatz WD Ltd | Hospitality | 2025 |
| Cafil Limited | Administrative & support | 2020 |
| Cairns Technology Group Ltd | Construction | 2022 |
| Cake House Bakery Limited | Wholesale & retail | 2019 |
| Cake House Bakery Wexham Ltd | Wholesale & retail | 2021 |
| Cakecusine Ltd | Wholesale & retail | 2022 |
| Cakes by NAZ Ltd | Manufacturing | 2024 |
| Calamari Limited | Information & communication | 2011 |
| Calcite Properties Limited | Real estate | 2025 |
| Caldarius Limited | Wholesale & retail | 2023 |
| Calgab Ltd | Professional & scientific | 2021 |
| Cali Joint Ltd | Hospitality | 2026 |
| Calibar Events Limited | Arts & recreation | 2009 |
| California Car Care Ltd | Administrative & support | 2017 |
| Calliari Homes (Bulkeley Avenue) Ltd | Construction | 2026 |
| Calliari Property Ltd | Construction | 2020 |
| Callum Park Homes Limited | Extraterritorial | 2013 |
| Callum Park Homes South East Limited | Construction | 2021 |
| Callum Park Management Company Limited | Households | 2024 |
| Callywhyt Limited | Health & social care | 2024 |
| Calming Hearts Limited | Health & social care | 2010 |
| Calotrans Ltd | Transport & logistics | 2019 |
| Calrox Ltd | Transport & logistics | 2018 |
| CAM Construction Ltd | Construction | 2026 |
| CAM Eco Energy Ltd | Construction | 2023 |
| Camara Logistics Ltd | Transport & logistics | 2024 |
| Camara Properties Ltd | Real estate | 2024 |
| Cambridge Clinic PVT Ltd | Health & social care | 2025 |
| Cameo Global Ltd. | Professional & scientific | 2003 |
| Cameron Forbes Limited | Information & communication | 2021 |
| Cameron Pizza Ltd | Hospitality | 2018 |
| Camies&Co Ltd | Administrative & support | 2022 |
| Camlot UK Limited | Real estate | 2024 |
| Campania Care Limited | Health & social care | 2020 |
| Campbell and Owen Management Limited | Real estate | 2015 |
| CAN Marketing Save the Planet Ltd | Professional & scientific | 2022 |
| Canford Healthcare Consultancy Limited | Extraterritorial | 2014 |