| Bunboo Ltd | Wholesale & retail | 2017 |
| Bungee Fitness Club Oxfordshire Ltd | Other services | 2026 |
| Burckhardt Compression (UK) Limited | Manufacturing | 2000 |
| BURGERLICIOUS2GO Ltd | Hospitality | 2023 |
| Burgess Reclamation Limited | Wholesale & retail | 2009 |
| Bursars Group Ltd | Wholesale & retail | 2021 |
| Burst Bubble Productions Ltd | Information & communication | 2020 |
| Burton Hill Transport Ltd | Transport & logistics | 2025 |
| Business Assessor Limited | Information & communication | 2012 |
| Business Case Guru Ltd | Information & communication | 2025 |
| Busy Bea's Bookkeeping Limited | Professional & scientific | 2025 |
| BVS Rescue Services Ltd | Wholesale & retail | 2008 |
| BW Architects Limited | Professional & scientific | 2019 |
| BY Bike & Boat Ltd | Manufacturing | 2015 |
| BY Degrees 2 Ltd | Construction | 2018 |
| BY Degrees Care Ltd | Health & social care | 2026 |
| BY Degrees Ltd. | Health & social care | 2017 |
| BY the Way Fashion Limited | Wholesale & retail | 2024 |
| C N C Solutions 2000 (Holdings) Limited | Professional & scientific | 2004 |
| C Williams Property Maintenance (Oxfordshire) Ltd | Construction | 2026 |
| C&C Flourish Ltd | Administrative & support | 2023 |
| C&C Online Ltd | Education | 2026 |
| C&C Properties Investor Ltd | Real estate | 2021 |
| C&M Mannings Ltd | Transport & logistics | 2026 |
| C&O Transp Ltd | Transport & logistics | 2026 |
| C&S Automotive Ltd | Wholesale & retail | 2019 |
| C.C.A Group Ltd | Wholesale & retail | 2022 |
| C.D. Real Estate Group Ltd | Real estate | 2025 |
| C.Rose Cleaning Limited | Administrative & support | 2022 |
| C2W Services Limited | Construction | 2025 |
| Cabbages & Condoms U K Limited | Hospitality | 2010 |
| Cabe Consulting Limited | Information & communication | 2011 |
| Cabrini House RTM Company Limited | Households | 2019 |
| Cactus V Limited | Hospitality | 2023 |
| CAD Distribution Limited | Wholesale & retail | 2009 |
| Cadbar Limited | Professional & scientific | 2017 |
| Cads-Uk Ltd | Information & communication | 2025 |
| Caimar Construction Ltd | Construction | 2021 |
| Caine Maintenance Services Ltd | Manufacturing | 2022 |
| Cairns Investments Limited | Real estate | 2020 |
| Cairns IT Consulting Ltd | Information & communication | 2019 |
| Calibre Solutions Limited | Education | 1994 |
| Callista Healthcare Ltd | Health & social care | 2014 |
| Calmingales Beauty Limited | Other services | 2022 |
| Calmshops Ltd | Wholesale & retail | 2020 |
| Calpeda Limited | Manufacturing | 1981 |
| Calthorpe Manor Ltd | Real estate | 2008 |
| Calvert Services Limited | Real estate | 2019 |
| Cambalt Road RTM Company Ltd | Households | 2019 |
| Camgrey Ltd | Professional & scientific | 2025 |
| Camm Holdings LLP | | 2017 |
| Canall Ltd | Wholesale & retail | 2026 |
| Candria Property Management Limited | Real estate | 2002 |
| Canna (B) Investors LLP | | 2008 |
| Cannon's Arboriculture Limited | Administrative & support | 2023 |
| Canpaths Limited | Professional & scientific | 2024 |
| Cantley Dental Centre Limited | Health & social care | 2013 |
| Capacitas Capital Ltd | Real estate | 2023 |
| Capital Risk Analytics Ltd | Information & communication | 2025 |
| Cappuchini Limited | Hospitality | 2014 |
| Capsey Clinical Communications Limited | Health & social care | 2015 |
| Capstone Design Consultants Oxford Limited | Professional & scientific | 2021 |
| Carbon Apex Ltd | Manufacturing | 2026 |
| Carbon Copy IT Limited | Wholesale & retail | 2014 |
| Carbon Creative Manufacturing Limited | Manufacturing | 2012 |
| Cardinal Property Group Limited | Financial services | 2011 |
| Cardiopulmonary Health Ltd | Health & social care | 2020 |
| Care Axis Solutions Limited | Health & social care | 2025 |
| Careys Store Ltd | Wholesale & retail | 2024 |
| Cargoearth Limited | Wholesale & retail | 2018 |
| Caribbean Biking Company Limited | Administrative & support | 2012 |
| Caribbean Fusion Food Limited | Hospitality | 2024 |
| Caring Careers Training Limited | Education | 2008 |
| Caris Property Services Limited | Real estate | 2024 |
| Caris Services Limited | Health & social care | 2024 |
| Carlton Royce Associates Limited | Professional & scientific | 2006 |
| Carmine Limited | Real estate | 2022 |
| Carnival of the Commons Ltd | Other services | 2026 |
| Carpet Trader (Bicester) Limited | Wholesale & retail | 2011 |
| Cassien Building Services Limited | Real estate | 2015 |
| Castec Studios Ltd | Information & communication | 2022 |
| Castle 2015 Ltd | Hospitality | 2015 |
| Castle Building Products (Oxon) Limited | Manufacturing | 2006 |
| Castle Traffic Ltd | Administrative & support | 2025 |
| Catered by Parky Limited | Hospitality | 2024 |
| Catrin Weston Consulting (UK) Limited | Professional & scientific | 2011 |
| Catriona Renk Limited | Construction | 2014 |
| Caulcott Limited | Professional & scientific | 2025 |
| Cavallo Macdonald Hebditch Limited | Administrative & support | 2004 |
| Cavendish Property Ventures Limited | Real estate | 2018 |
| CB IT Resourcing Ltd | Information & communication | 2019 |
| CB W&D Ltd | Wholesale & retail | 2024 |
| CD Solutions (Midlands) Limited | Professional & scientific | 2018 |
| CDG People Strategies Limited | Professional & scientific | 2017 |
| Cedar & Stone Investments Ltd | Real estate | 2025 |
| Cedar & Stone Ventures Ltd | Real estate | 2025 |
| Cedar Property Services Ltd | Real estate | 2024 |
| CEG LP2 (II) Limited | Real estate | 2025 |
| Celebration of Life Centres Limited | Other services | 2021 |
| Celsius Software Limited | Information & communication | 2003 |