| B&A Travel Limited | Hospitality | 2015 |
| B-I-Beauty Solution Limited | Administrative & support | 2020 |
| B. a. Knott (Oxford) Ltd. | Construction | 2003 |
| B.E.C. British Education Centre Ltd | Education | 2009 |
| B.M.A. Varsity Limited | Administrative & support | 1983 |
| B1 Pharma Ltd | Professional & scientific | 2018 |
| B1G BEN Ltd | Construction | 2023 |
| B2B Financing LLP | | 2012 |
| BA Property Limited | Real estate | 2017 |
| BA12GGG Ltd | Professional & scientific | 2025 |
| Babawale Akinpelu & Company Limited | Health & social care | 2019 |
| Babecintegrated Limited | Public administration | 2023 |
| Babka Ltd | Manufacturing | 2018 |
| Baby College Limited | Education | 2015 |
| Babyclick Ltd | Wholesale & retail | 2025 |
| Babylon Food Oxford Ltd | Hospitality | 2025 |
| Babylon Trading Company Ltd | Wholesale & retail | 2008 |
| Babytrim Limited | Extraterritorial | 2016 |
| Back Office Boss Ltd | Professional & scientific | 2020 |
| Back to Life Property Group Limited | Real estate | 2025 |
| Backontruck Ltd | Hospitality | 2024 |
| Bacx Life Sciences Ltd. | Manufacturing | 2020 |
| Badger Lane Management Company Limited | Administrative & support | 2014 |
| Badlands Adventures Ltd | Administrative & support | 2025 |
| Bagley Edge Group Ltd | Professional & scientific | 2016 |
| Bahk Holdings Limited | Financial services | 2014 |
| Baifu Limited | Extraterritorial | 2014 |
| Bailey Decorative Art and Furniture Ltd | Wholesale & retail | 2024 |
| Baileycharm Ltd | Professional & scientific | 2023 |
| Bainton Bikes Limited | Arts & recreation | 2009 |
| Bakers Travel Limited | Transport & logistics | 2014 |
| Bakery Court Management Limited | Extraterritorial | 2013 |
| Bakewell Pools Limited | Construction | 2001 |
| Bal's Barber Ltd | Other services | 2018 |
| Balaton Construction Ltd | Construction | 2025 |
| Balfa East Limited | Hospitality | 2025 |
| Balliol College Developments Limited | Hospitality | 2002 |
| Ballymena Hydrogen Limited | Administrative & support | 2022 |
| Bambrooks Mews Limited | Real estate | 2012 |
| Bamford Browne Limited | Real estate | 2014 |
| Bamford BUS Company Holdings Limited | Administrative & support | 2019 |
| Bamford BUS Company Limited | Manufacturing | 2019 |
| Bamford BUS Company Parts and Aftercare Limited | Administrative & support | 2019 |
| Bamford Gore Browne Limited | Administrative & support | 2012 |
| Bamford Property Ireland Limited | Administrative & support | 2016 |
| Bamins Ltd | Administrative & support | 2016 |
| Bamjoy Construction & Security Ltd | Construction | 2023 |
| Bammy International Ltd | Health & social care | 2023 |
| Banbury Butchers Ltd | Wholesale & retail | 2024 |
| Banbury Cash & Carry Ltd | Wholesale & retail | 2024 |
| Banbury Frozen Foods Limited | | 1975 |
| Banbury Road Management Company Limited | Households | 1998 |
| Banc D'Arguin, and Coastal and Marine Biodiversity Trust Fund Limited | Arts & recreation | 2009 |
| Bangkok Bright Ltd | Hospitality | 2024 |
| Bangkok House Enterprise Limited | Hospitality | 2017 |
| Bania Transport Ltd | Transport & logistics | 2024 |
| Bankrupt Bar Ltd | Hospitality | 2022 |
| Banks Geoscience Limited | Administrative & support | 2005 |
| Bannits Limited | Other services | 2004 |
| Banzhou Electric Ltd | Agriculture & fishing | 2020 |
| Banzhou Services Ltd | Real estate | 2022 |
| Bara Clothing Ltd | Wholesale & retail | 2023 |
| Barach Ltd | Administrative & support | 2011 |
| Barber & Reynolds (Woolhampton) Limited | Wholesale & retail | 1946 |
| Barbosa Detail Limited | Administrative & support | 2025 |
| Barbury Hill Limited | Wholesale & retail | 2020 |
| Barclay House (Banbury Road) Limited | Households | 2012 |
| Bardon Hill LOW Carbon Hydrogen Limited | Administrative & support | 2022 |
| Barefoot Bakery Ltd | Wholesale & retail | 2021 |
| Barefoot Jericho Limited | Wholesale & retail | 2017 |
| Barefoot Oxford Group Limited | Manufacturing | 2023 |
| Barefoot Oxford Limited | Manufacturing | 2013 |
| Barkat Enterprise Ltd | Real estate | 2018 |
| Barker Books Ltd | Wholesale & retail | 2026 |
| Barking Dog Antiques Limited | Wholesale & retail | 2014 |
| Barnabas Nominees Limited | Extraterritorial | 2012 |
| Barnlando Limited | Construction | 2017 |
| Baron PUB Limited | Hospitality | 2019 |
| Baroshima Barbers Ltd | Other services | 2026 |
| Barracks Lane Community Garden Project | Arts & recreation | 2006 |
| Barretts Domiciliary Care Ltd | Health & social care | 2024 |
| Barrington Hotels Limited | Hospitality | 2000 |
| Barrwax Limited | Administrative & support | 1992 |
| Barters Land Limited | Real estate | 2022 |
| Bartlett House Management Company Ltd | Real estate | 2020 |
| Barton Community Association | Other services | 2003 |
| Barworth Homes Limited | Construction | 2024 |
| Base Holdings Group UK Ltd | Wholesale & retail | 2023 |
| Base Living Limited | Real estate | 2026 |
| Basetech Support Ltd | Other services | 2024 |
| Basis B2B Research Limited | Professional & scientific | 2025 |
| Basis Health London Limited | Professional & scientific | 2019 |
| Basis Research Group Holdings Limited | Professional & scientific | 2023 |
| Basis Research Group Limited | Professional & scientific | 2020 |
| Basis Research Limited | Professional & scientific | 1996 |
| Bastion Insurance Services Ltd | Financial services | 2013 |
| Bath River Cruises Ltd | Arts & recreation | 2026 |
| Batic Ltd | Real estate | 2022 |
| Batoor Ltd | Hospitality | 2018 |
| Baupro Ltd | Professional & scientific | 2021 |