| Bury Farm Sharpenhoe Limited | Agriculture & fishing | 2023 |
| Butler's PIE Company Limited | Manufacturing | 2017 |
| Butler's PIE Shop Limited | Wholesale & retail | 2017 |
| Buttress Group Limited | Wholesale & retail | 1982 |
| Buttress Holdings Limited | Financial services | 2020 |
| BVS Brackley Limited | Wholesale & retail | 2012 |
| BVS Gayler Ltd | Wholesale & retail | 2020 |
| C & M Sons Ltd | Professional & scientific | 2023 |
| C B Sports Ventures Ltd | Real estate | 2022 |
| C J Refurbishments Limited | Real estate | 2024 |
| C Wyatt Heating Limited | Construction | 2012 |
| C. Gerhardt UK Limited | Wholesale & retail | 1987 |
| C2C Transport Limited | Transport & logistics | 2014 |
| Cafe Cool Limited | Wholesale & retail | 2016 |
| Cafe Fusion Brackley Ltd | Health & social care | 2025 |
| Caked in Bread Limited | Manufacturing | 2014 |
| CAL Consultancy Limited | Administrative & support | 2010 |
| Calgroup Limited | Wholesale & retail | 2015 |
| Caliber Construction Limited | Construction | 2012 |
| Calm Coffee Roastery Ltd | Manufacturing | 2024 |
| Calmac Tyres Limited | Wholesale & retail | 2007 |
| Cameron Fraser Developments Limited | Professional & scientific | 2007 |
| Cammack Consulting Limited | Professional & scientific | 2022 |
| Canine Company (the Bark Park) Ltd | Other services | 2023 |
| Canine Company Brackley Ltd | Other services | 2023 |
| Canine Company Franchise Ltd | Other services | 2021 |
| Canine Company Towcester Ltd | Other services | 2024 |
| Car Body (Holdings) Limited | Financial services | 2017 |
| Carbon Copy Consulting Limited | Professional & scientific | 2024 |
| Carbon Repair UK Ltd | Manufacturing | 2014 |
| Cardoe Interiors Limited | Manufacturing | 2015 |
| Carow Developments Ltd | Construction | 2016 |
| Carpaintuk Limited | Wholesale & retail | 2019 |
| Carpathia Ventures Limited | Extraterritorial | 2014 |
| Carpet & Flooring Outlet Ltd | Wholesale & retail | 2023 |
| Carr Quality Consultancy Limited | Professional & scientific | 2003 |
| Carrera Partners Ltd | Information & communication | 2026 |
| Carthew Limited | Other services | 2023 |
| Cartwrights Sports Limited | Wholesale & retail | 2013 |
| Carty House Properties Limited | Real estate | 2025 |
| Casamae Ltd | Health & social care | 2025 |
| Castlegate 123 Limited | Extraterritorial | 2015 |
| Caterparts Limited | Wholesale & retail | 2008 |
| CB Services (NW) Ltd | Professional & scientific | 2024 |
| CC Technical Support Limited | Wholesale & retail | 2020 |
| CDM Electrical Installations Ltd | Construction | 2026 |
| CDX Technologies Ltd | Information & communication | 2025 |
| CE2 Ltd | Professional & scientific | 2026 |
| Centre TAP Electronics Ltd | Manufacturing | 2019 |
| Chadleigh Limited | Households | 1972 |
| Charlie H Ltd | Wholesale & retail | 2018 |
| Chatfield Furniture Conservation Limited | Other services | 2007 |
| Check My Boat Limited | Manufacturing | 2022 |
| Cheney Park Management Company Limited | Administrative & support | 2016 |
| Cherwell Technology Ltd | Administrative & support | 2024 |
| Ches & Co Design Studio Limited | Professional & scientific | 2025 |
| Chigs Inspire Ltd | Health & social care | 2021 |
| Child 1ST Properties Limited | Real estate | 2012 |
| Chique Hair Ltd | Other services | 2023 |
| CHM Dixon Limited | Financial services | 2025 |
| CHM Management Limited | Real estate | 2026 |
| Choozlc Ltd | Manufacturing | 2025 |
| Christmas Installed Limited | Wholesale & retail | 2026 |
| Churchill 8 Limited | Households | 2024 |
| Cielo BLU Consultancy Limited | Information & communication | 2025 |
| Cirrus UK Training Limited | Transport & logistics | 2004 |
| CJM Bookkeeping Services Limited | Professional & scientific | 2018 |
| Clegplan Building Limited | Manufacturing | 1977 |
| Clemence Bergal Limited | Professional & scientific | 2022 |
| Clifford Chambers Management Company Limited | Households | 2020 |
| Clinetech Limited | Information & communication | 2016 |
| Clip 'N Climb Brackley Ltd | Hospitality | 2018 |
| Clockwork Design Ltd | Information & communication | 2009 |
| CM Tutor Solutions Limited | Education | 2022 |
| CMG Composites Limited | Manufacturing | 2025 |
| CMP Plumbing & Heating Ltd | Construction | 2018 |
| Code Automotive Ltd | Professional & scientific | 2012 |
| Cofintel Limited | Information & communication | 2024 |
| Collins Engineering Croughton Limited | Manufacturing | 2003 |
| Collz & B Estates Ltd | Real estate | 2022 |
| Collz Digital Design Ltd | Education | 2024 |
| Colorado Sunsites Limited | Professional & scientific | 2026 |
| Colorwerxuk Limited | Wholesale & retail | 2022 |
| Colready Highlands Limited | Wholesale & retail | 2023 |
| Colucci's Barber Shop Ltd | Other services | 2018 |
| Complete Systems (UK) Limited | Administrative & support | 2012 |
| Comptech Engineering Ltd | Wholesale & retail | 2016 |
| Computer Plan Limited | Information & communication | 1987 |
| Computercare Assets Management Limited | Wholesale & retail | 2024 |
| Construction Recruitment Company (Nationwide) Limited | Administrative & support | 2024 |
| Contemporary Glass Society | Arts & recreation | 2004 |
| Copy Chops Ltd | Professional & scientific | 2019 |
| Corona Blue Business Services Ltd | Professional & scientific | 2018 |
| Cotehatch Limited | Construction | 1979 |
| Cotswold Finish Ltd | Construction | 2026 |
| Countenance Limited | Real estate | 1982 |
| Countrywide Garden Maintenance Services Limited | Agriculture & fishing | 1986 |
| Countrywide Grounds Maintenance Limited | Administrative & support | 1993 |
| County Cars(Oxford)Limited | Professional & scientific | 1965 |
| Courtyard Hub Ltd | Administrative & support | 2026 |