| C.J. Morris & Associates Limited | Health & social care | 2004 |
| C.J.H Cleaning Services Ltd | Administrative & support | 2010 |
| C.J.L Ceramics and Natural Stone Ltd | Construction | 2013 |
| C.J.M. Home & Window Products Limited | | 1980 |
| C.J.Plant Limited | Wholesale & retail | 2006 |
| C.L.Smith(Builders)Limited | Construction | 1955 |
| C.L.T. Properties Limited | Real estate | 1998 |
| C.M.Brown and Company Limited | Construction | 1945 |
| C.M.S. Solutions Inc (Midlands) Limited | Professional & scientific | 2019 |
| C.M.T. Industrial Supplies (Wales) Limited | | 1936 |
| C.O.B.Engineering Limited | Real estate | 1971 |
| C.O.G Apparel Ltd | Wholesale & retail | 2025 |
| C.P. Electronics Limited | Extraterritorial | 1971 |
| C.P.A. Fabrications Limited | Manufacturing | 1993 |
| C.P.Benbow Ltd | Construction | 2010 |
| C.P.D. Holdings Limited | Administrative & support | 1988 |
| C.P.R Security Ltd | Energy | 2022 |
| C.S. Brooks (B'Ham) Limited | Real estate | 1980 |
| C.S.E. Cooling System England Ltd | Construction | 2023 |
| C.S.H. Finance Limited | Financial services | 1984 |
| C.S.I. Services Limited | Information & communication | 2006 |
| C.T Carpentry & Joinery Ltd | Construction | 2023 |
| C.Uk Bridge Limited | Professional & scientific | 2025 |
| C.W & C.S Ltd | Wholesale & retail | 2021 |
| C.W. Cheney & SON Limited | Manufacturing | 1982 |
| C.W. Maintenance Limited | Construction | 2019 |
| C.Walt Global Ltd | Transport & logistics | 2025 |
| C14 Designs Limited | Professional & scientific | 2012 |
| C2 Capital Ltd | Hospitality | 2022 |
| C2A Investments Ltd | Real estate | 2025 |
| C2C Freight Ltd | Transport & logistics | 2020 |
| C2CLEANING Ltd | Administrative & support | 2026 |
| C2M Housing Limited | Hospitality | 2025 |
| C2NICE Ltd | Transport & logistics | 2025 |
| C3 Cost Consultants Ltd | Professional & scientific | 2020 |
| C3 Management Consulting Limited | Professional & scientific | 2014 |
| C3 Midlands Holdings Ltd | Financial services | 2024 |
| C3 Midlands Ltd. | Manufacturing | 2002 |
| C3 Trading Ltd | Wholesale & retail | 2024 |
| C3LADS Ltd | Wholesale & retail | 2024 |
| C4 Pro Gym Ltd | Wholesale & retail | 2024 |
| C4 Vibez Ltd | Hospitality | 2022 |
| C4-UK Limited | Wholesale & retail | 2007 |
| C4C Consulting Limited | Administrative & support | 2019 |
| C4C Investments Limited | Real estate | 2013 |
| C4H Group Ltd | Administrative & support | 2016 |
| C4RE Group CIC | Education | 2021 |
| C6 Ltd | Wholesale & retail | 2020 |
| CA Entertainment Group Ltd | Hospitality | 2022 |
| CA Nottingham Limited | Hospitality | 2023 |
| Ca&Py Transporting Limited | Wholesale & retail | 2023 |
| Ca-A Industries LLP | | 2010 |
| Caam Group Ltd | Real estate | 2023 |
| Caar Limited | Other services | 2004 |
| Caav Investment Ltd. | Real estate | 2024 |
| CAB Crash Direct Limited | Wholesale & retail | 2015 |
| CAB OPS Limited | Wholesale & retail | 2025 |
| CAB Safe - Security Solutions Limited | Administrative & support | 2007 |
| CAB Services Direct Ltd | Wholesale & retail | 2025 |
| CAB Tours (Birmingham) Limited | Transport & logistics | 2024 |
| Cab-Formations Ltd | Administrative & support | 2024 |
| Cabana Homes Limited | Construction | 2017 |
| Cabbage White Linen Services Limited | Other services | 2017 |
| Cabbella Hair Salon Limited | Other services | 2012 |
| Cabex Limited | Manufacturing | 1999 |
| Cabfix Ltd | Wholesale & retail | 2020 |
| Cabiria Limited | Professional & scientific | 2015 |
| Cable & Alloys (Willenhall) Limited | Wholesale & retail | 2008 |
| Cable and Wholesale Supplies Limited | Wholesale & retail | 2016 |
| Cable Harness Works Ltd | Manufacturing | 2026 |
| Cable Jointing Solutions Limited | Manufacturing | 2015 |
| Cable Wire Guru Ltd | Wholesale & retail | 2024 |
| Cable-Talk (UK) Limited | Construction | 2010 |
| Cablecomm Communications Ltd | Administrative & support | 2011 |
| Cables 4 Phones Limited | Wholesale & retail | 2021 |
| Cablestar Networks Ltd | Information & communication | 2025 |
| Cabnav Ltd | Information & communication | 2023 |
| Cabplus Ltd | Transport & logistics | 2025 |
| Cabura Ltd | Wholesale & retail | 2025 |
| Cabwave UK Ltd | Transport & logistics | 2026 |
| Cacovean Construct Ltd | Construction | 2025 |
| Cactus Construction Limited | Construction | 2023 |
| Cactus Health Ltd | Manufacturing | 2023 |
| Cactus Support Services Ltd | Administrative & support | 2021 |
| CAD 33 Ltd | Manufacturing | 2024 |
| CAD Architecture (Midlands) Ltd | Professional & scientific | 2012 |
| CAD Design Solutions 2010 Ltd | Professional & scientific | 2010 |
| Cadaptor Solutions Ltd | Administrative & support | 2019 |
| Cadbury Athletic Walking Football Club Ltd | Education | 2026 |
| Cadbury Court Ltd | Real estate | 2021 |
| Cadbury Homes Ltd | Households | 2018 |
| Cadbury Homes SA Limited | Real estate | 2023 |
| Cadbury Mondelez Pension Trust Limited | Professional & scientific | 1968 |
| Cadbury Schweppes Pension Trust (Property) Limited | Professional & scientific | 1961 |
| Cadbury UK Limited | Manufacturing | 1919 |
| Cadddan Estates Ltd | Extraterritorial | 2022 |
| Cadddan Ltd | Professional & scientific | 2018 |
| Caddworx Ltd | Other services | 2020 |
| Caden Cooper (Development) Limited | Professional & scientific | 2021 |
| Cadence Band Management Limited | Other services | 2023 |