| Blam Furniture Makers Limited | Manufacturing | 2012 |
| Bleckmann Logistics UK Limited | Transport & logistics | 2017 |
| Bleckmann Solutions UK Limited | Transport & logistics | 2016 |
| Bleckmann UK 2 Limited | Transport & logistics | 2024 |
| Bleckmann UK Limited | Transport & logistics | 2014 |
| Bliss Beauty of Thame Ltd | Health & social care | 2012 |
| Blockhouse International Limited | Wholesale & retail | 2009 |
| Blossom Educational Ltd | Education | 2016 |
| Blue Blood Sports Limited | Wholesale & retail | 2018 |
| Blue Coffee Consulting Ltd | Professional & scientific | 2014 |
| Blue Tandem Ltd | Information & communication | 2019 |
| Bluebell Bookkeeping Ltd | Professional & scientific | 2014 |
| BNS Worldwide Ltd | Manufacturing | 2021 |
| Bobcat Group Holdings Ltd | Transport & logistics | 2023 |
| Bobcat Logistics Limited | Transport & logistics | 2017 |
| Body Tech Limited | Wholesale & retail | 2022 |
| Bonhard Ltd | Professional & scientific | 2025 |
| Bonnar Fire Risk Assessments Ltd | Public administration | 2025 |
| Bonners Yard Management Company Limited | Households | 2012 |
| Booker Tate (Overseas) Limited | Professional & scientific | 1991 |
| Booker Tate Holdings Limited | Professional & scientific | 2000 |
| Booker Tate Limited | Professional & scientific | 1988 |
| Box Anaesthesia Ltd | Health & social care | 2023 |
| Box of Toys Audio Limited | Information & communication | 2011 |
| Box Technologies (Holdings) Limited | Professional & scientific | 2004 |
| Box Technologies Limited | Information & communication | 1992 |
| Bozon People Development Limited | Professional & scientific | 2010 |
| Bradley Automation Limited | Administrative & support | 2011 |
| Braeburn Construction Limited | Construction | 2018 |
| Bramley Consultants Limited | Information & communication | 1998 |
| Branch Electrical Services Limited | Manufacturing | 2014 |
| Bricks and Bamboo Limited | Real estate | 2021 |
| Bridgmore Brown Limited | Professional & scientific | 2004 |
| Bright Exchanges Ltd | Education | 2016 |
| Bright Money Independent Ltd | Financial services | 2011 |
| Brightcap Partners Limited | Financial services | 2026 |
| Brighton International Animation Festival CIC | Information & communication | 2024 |
| Britannia Cars Oxon Ltd | Transport & logistics | 2026 |
| Broadleaf Joinery (Oxford) Limited | Construction | 1993 |
| Broken Antler Limited | Information & communication | 2005 |
| Broken TEE Golf Limited | Professional & scientific | 2024 |
| Brotherford Ltd | Information & communication | 2026 |
| Brusselstown Limited | Financial services | 2011 |
| Bssy Holdings Limited | Financial services | 2021 |
| Bubbleo Ltd | Real estate | 2021 |
| Buchanan Surveys Limited | Other services | 2011 |
| Bucket List Prints Limited | Wholesale & retail | 2020 |
| Buckminster Farms Limited | Agriculture & fishing | 2010 |
| Bucks Business Growth Ltd | Professional & scientific | 2020 |
| Bucks Property Construction & Maintenance Ltd | Construction | 2003 |
| Building for Success Limited | Real estate | 2022 |
| Built With Understanding Limited | Other services | 2011 |
| Bunge Corporation Limited | Financial services | 1995 |
| Bunge UK Dormant Limited | Extraterritorial | 2001 |
| Bunge UK Limited | Wholesale & retail | 1969 |
| Burbury Construction Limited | Construction | 2025 |
| Burgundy Information Services Ltd | Administrative & support | 2007 |
| Busi Cleaners Ltd | Administrative & support | 2025 |
| Business Modernisation Limited | Information & communication | 2026 |
| Business Yoga Limited | Arts & recreation | 2020 |
| C & a Wright Limited | Professional & scientific | 2009 |
| C & C Military Ltd. | Wholesale & retail | 2010 |
| C & H Holland Limited | Agriculture & fishing | 2014 |
| C Curtis Property Ltd | Real estate | 2025 |
| C4MILES Ltd | Professional & scientific | 2023 |
| CAD Quick Limited | Information & communication | 1995 |
| Cadence Planning Limited | Professional & scientific | 2018 |
| CAL Recruitment Limited | Administrative & support | 2018 |
| Calming Quarters Properties Ltd | Real estate | 2023 |
| Caloan Investments Ltd | Real estate | 2015 |
| Cambervine Limited | | 1988 |
| Camden Carpentry Ltd | Construction | 2021 |
| Camelhorse Services Ltd | Professional & scientific | 2025 |
| Cammack S&C Ltd | Arts & recreation | 2024 |
| Capital Corporate Events Limited | Administrative & support | 2016 |
| Car Transformers Limited | Wholesale & retail | 2014 |
| Carbonovia Ltd | Professional & scientific | 2022 |
| Card Procurement Consultancy Limited | Professional & scientific | 2018 |
| Carden Healthcare Services Limited | Health & social care | 2018 |
| Carefront Care Services Ltd | Health & social care | 2018 |
| Carlow/Aesthetics Ltd | Other services | 2023 |
| Carmichael Engineering & Consulting Limited | Construction | 2007 |
| Carmichael Site Services Limited | Construction | 1997 |
| Carmichael UK Trades & Labour Limited | Extraterritorial | 2004 |
| Carmichaeluk Civil Engineering Recruitment Limited | Extraterritorial | 2004 |
| Cask MED Ltd | Other services | 2018 |
| Caswell House Limited | Hospitality | 2023 |
| Catherine Wheel (Oxford) Limited | Hospitality | 2024 |
| Catholic Insurance Service Limited | Financial services | 2002 |
| Cavendish Events Ltd | Hospitality | 2019 |
| CBC (Oxford 2) Management Company Limited | Professional & scientific | 2005 |
| Cdcw Ltd | Professional & scientific | 2020 |
| CDI Property Services Limited | Financial services | 2018 |
| Cedar Experts Ltd | Professional & scientific | 2025 |
| CEE Consulting Ltd | Professional & scientific | 2018 |
| Centaur Tree Services Limited | Agriculture & fishing | 2014 |
| Centre Holdings Limited | Professional & scientific | 1967 |
| CFT Holdings Ltd | Financial services | 2022 |
| Chaletmanager Limited | Information & communication | 2009 |
| Chalford Property Group Ltd | Real estate | 2023 |