| Avignon Management Ltd | Professional & scientific | 2016 |
| Avirit Limited | Real estate | 2022 |
| Avirit Technology Solutions (UK) Ltd | Professional & scientific | 2026 |
| AVY Tejas Limited | Real estate | 2019 |
| AW Architectural Design Ltd | Professional & scientific | 2017 |
| AWK Design Ltd | Professional & scientific | 2024 |
| AWK Project Management Ltd | Construction | 2021 |
| Awre Ltd | Professional & scientific | 2025 |
| Axiom Test Engineering Limited | Professional & scientific | 2023 |
| Ayam Manis Ltd | Information & communication | 2025 |
| Ayles Properties Ltd | Real estate | 2021 |
| Aylesbury Dental Care Limited | Health & social care | 2006 |
| Aylesbury Vale Community Trust | Arts & recreation | 2009 |
| Aylesnet IT Solutions Limited | Information & communication | 2012 |
| AYR Systems Limited | Manufacturing | 2026 |
| Ayrism Consulting Limited | Professional & scientific | 2016 |
| B & D Plastering Services Limited | Construction | 2015 |
| B.E. Allen & Sons, Limited | Wholesale & retail | 1973 |
| B.K.G. Holdings Ltd | Financial services | 2019 |
| Babbolio Ltd | Wholesale & retail | 2024 |
| Back to Health Physiotherapy Limited | Administrative & support | 2007 |
| Bader Holdings UK Ltd | Information & communication | 2020 |
| Balmer Accountancy Limited | Extraterritorial | 2016 |
| Balmer Limited | Professional & scientific | 2012 |
| Balmoor Ltd | Financial services | 2017 |
| Banbury Aerials Limited | Other services | 2001 |
| Banbury Bodyshop Services Ltd | Wholesale & retail | 2003 |
| Banbury Bodyshop Supplies LLP | | 2012 |
| Banbury Heating Supplies Ltd | Wholesale & retail | 2012 |
| Banbury Motors Ltd | Wholesale & retail | 2010 |
| Baobab Group Limited | Extraterritorial | 2022 |
| Barford Holdings Ltd | Real estate | 2015 |
| Barry-Parker Film Limited | Information & communication | 2015 |
| Batanai Group Limited | Hospitality | 2020 |
| BDP Business Advisors Limited | Professional & scientific | 2023 |
| Beam & Bulb Limited | Wholesale & retail | 2026 |
| Bean & Bear Property Holdings Ltd | Real estate | 2024 |
| Beaumont Court Residents Management Company Limited | Households | 2019 |
| Beaumont Recycling Ltd | Agriculture & fishing | 1997 |
| Bechardstreet Limited | Real estate | 2013 |
| Bedfordshire Botanic Nursery Limited | Wholesale & retail | 2016 |
| Bedfordshire Botanics Limited | Wholesale & retail | 2016 |
| Beeches Medical Services Limited | Extraterritorial | 2014 |
| Bell Flow Systems Holdings Limited | Financial services | 2017 |
| Bell Flow Systems Limited | Administrative & support | 1997 |
| Bellenden Signs Limited | Professional & scientific | 2010 |
| Beltod Properties Ltd | Real estate | 2020 |
| Beltod Solutions Ltd | Information & communication | 2014 |
| Bemchimmo UK Limited | Real estate | 2022 |
| BEN Beshaw Consulting Limited | Professional & scientific | 2023 |
| BEN Olding Games Limited | Information & communication | 2010 |
| Benchstop Limited | Construction | 2011 |
| Beneath the Dust Jacket Limited | Wholesale & retail | 2024 |
| Bengal Flames Limited | Hospitality | 2019 |
| BENGAL(786) Ltd | Hospitality | 2025 |
| Benson Lock Ltd | Professional & scientific | 2012 |
| Berjaya Bintang Ltd | Real estate | 2025 |
| Berjaya Limited | Hospitality | 2018 |
| Berjaya Star Limited | Hospitality | 2026 |
| Berry Ottaway & Associates Limited | Professional & scientific | 1979 |
| Bersta Ltd | Professional & scientific | 2014 |
| Bespoke Component Solutions Limited | Manufacturing | 2023 |
| Bespoke Event Hire Ltd | Hospitality | 2024 |
| Bespoke Safety Solutions (BSS) Ltd | Professional & scientific | 2013 |
| Betaquip Holdings Limited | Professional & scientific | 2016 |
| Beuzu Investments Limited | Real estate | 2020 |
| Bexcartss Ltd | Wholesale & retail | 2026 |
| BGC Trustee Limited | Extraterritorial | 2021 |
| BHP Bees Ltd | Agriculture & fishing | 2025 |
| BHP Honey Ltd | Wholesale & retail | 2025 |
| BHP Queens Ltd | Agriculture & fishing | 2020 |
| Bidteck Innovations Limited | Wholesale & retail | 2010 |
| Bidwriting.Com Limited | Professional & scientific | 2007 |
| Biffo Limited | Real estate | 1996 |
| Big Cookie Ltd | Other services | 2014 |
| Bill Robins Limited | Professional & scientific | 2003 |
| Bindile Limited | Administrative & support | 2023 |
| Birchcooper Accounting Services Limited | Information & communication | 2001 |
| BIS Health Ltd | Health & social care | 2023 |
| Bismillah Investments ( MK ) Limited | Real estate | 2024 |
| Bitswiztech Ltd | Information & communication | 2021 |
| Biwines Ltd | Wholesale & retail | 2020 |
| Biznomy Solutions UK Limited | Information & communication | 2019 |
| BKC Creative Limited | Professional & scientific | 2016 |
| Black Book Resourcing Ltd | Professional & scientific | 2019 |
| Black Box Ltd | Professional & scientific | 2015 |
| Black Dog HR Consultancy Limited | Professional & scientific | 2008 |
| Black Shed Works Limited | Construction | 2014 |
| Blackbird Films Limited | Arts & recreation | 2017 |
| Blackbull Holmes Developments Limited | Construction | 2024 |
| Blackpit Events Limited | Other services | 2025 |
| Blinds Your Way Ltd | Wholesale & retail | 2023 |
| Blue Aroma Ltd | Hospitality | 2018 |
| Blue Flame Heating (Banbury) Ltd | Construction | 2011 |
| Blue HUT Productions Ltd | Information & communication | 2026 |
| Blue Legend Software Limited | Information & communication | 1993 |
| Blue Wave Plumbing Services Ltd | Construction | 2023 |
| Bluebell Wood Resources Limited | Administrative & support | 2010 |
| Bluesky Portfolio Ltd | Real estate | 2025 |
| BM Finance Limited | Professional & scientific | 2018 |