| Ballards Properties LLP | | 2004 |
| Ballards Property Management Limited | Real estate | 2010 |
| BAM BAM Patisserie Ltd | Hospitality | 2026 |
| Bandersnatch Ltd | Arts & recreation | 2019 |
| Bantry Mechanical Ltd | Construction | 2014 |
| Barkham Manor Farm Ltd | Agriculture & fishing | 1999 |
| Barkshire Hydrotherapy Ltd | Professional & scientific | 2021 |
| Baronsmead Court Ltd | Households | 2020 |
| Barracuda Capital Limited | Financial services | 2026 |
| Barron Consulting Limited | Professional & scientific | 2020 |
| Barron Escapes Ltd | Administrative & support | 2026 |
| Barry Duggan & Co Limited | Professional & scientific | 2006 |
| Basestack Group Ltd | Information & communication | 2022 |
| Basilisk Finance Ltd | Professional & scientific | 2015 |
| Baskerville Opco Limited | Hospitality | 2022 |
| Battalion Court Management Company Limited | Households | 2017 |
| BAY1 Ltd | Hospitality | 2021 |
| Baybel Ltd | Information & communication | 2021 |
| BBO Recruitment Ltd | Administrative & support | 2016 |
| BCG Student Ltd | Real estate | 2015 |
| BE Well Care Ltd | Health & social care | 2019 |
| Beacon Investments LLP | | 2017 |
| Beaconsfield Glazing & Window Centre Limited | Construction | 2016 |
| Bead Holdings Limited | Financial services | 2025 |
| Bear Property Ltd | Real estate | 2026 |
| Beat Blue Limited | Financial services | 2023 |
| Beat Holdings Limited | Financial services | 2023 |
| Beat Street Audio Ltd | Information & communication | 2026 |
| Beauchamp Place (Cowley) Limited | Households | 1994 |
| Beaumont Pharma Ltd | Wholesale & retail | 2020 |
| BEE8 Ltd | Professional & scientific | 2018 |
| Beechurst and Partners Limited | Information & communication | 1976 |
| Beechwood Legal Advisors Limited | Professional & scientific | 2025 |
| Behavioural Games Ltd | Information & communication | 2018 |
| Behind the Scenes Productions Limited | Information & communication | 2015 |
| Being Human Consulting Limited | Professional & scientific | 2022 |
| Being Human Legal Consulting Limited | Professional & scientific | 2020 |
| Being Human Solutions Limited | Professional & scientific | 2023 |
| Bell Street Management Company Limited | Households | 1997 |
| Bells FX Limited | Administrative & support | 2024 |
| Belong Marketing Limited | Other services | 2011 |
| BEN Alder Limited | Hospitality | 2020 |
| Beretun Holdings Ltd | Financial services | 2023 |
| Berks Construction Limited | Construction | 2018 |
| Berkshire Menopause Clinic Limited | Health & social care | 2022 |
| Bernard Barlow Close One RTM Company Limited | Households | 2021 |
| Bernard Barlow Close Two RTM Company Limited | Households | 2021 |
| Bertram House Residents Freehold Management Ltd | Households | 2021 |
| Bespoke Home Concierge Ltd | Other services | 2020 |
| Bespoke Home Moves Ltd | Transport & logistics | 2020 |
| Best for Balls Limited | Wholesale & retail | 2005 |
| Bhm-B Ltd | Real estate | 2024 |
| Bhowlingitconsulting Ltd | Information & communication | 2025 |
| Big Beaumont Ltd | Wholesale & retail | 2018 |
| Big Blue Bear Ltd | Professional & scientific | 2018 |
| Big Dog BED Company Ltd | Manufacturing | 2011 |
| Biggs Consulting Ltd | Information & communication | 2021 |
| Bignold Estates Ltd | Construction | 2019 |
| Bignold Rentals Limited | Real estate | 2025 |
| Bikeable Ltd | Wholesale & retail | 2020 |
| Bilocation Limited | Information & communication | 2008 |
| Bionyx Development Ltd | Construction | 2026 |
| Bishopstow Management Limited | Households | 2000 |
| Black Compass Ltd | Information & communication | 2017 |
| Blacklock RJ Consulting Ltd | Professional & scientific | 2025 |
| Blakes Pet Food and Fishing Bait Ltd | Other services | 2012 |
| Blancanvas Ltd | Professional & scientific | 2006 |
| Blanchards Law Ltd | Professional & scientific | 2011 |
| Blenheim Gate (Woodstock) Management Limited | Households | 2012 |
| Blenheim Gate (Woodstock) NO. 2 Management Limited | Extraterritorial | 2008 |
| Bloc Catering Limited | Hospitality | 2012 |
| Blue Chip Residential Limited | Real estate | 2013 |
| Blue Dolphin Fish Bar Ltd | Hospitality | 2024 |
| Blue Nettle Ltd | Professional & scientific | 2019 |
| Blue Rock Technology Ltd | Professional & scientific | 2013 |
| Blue Whippet Investments Ltd | Professional & scientific | 2021 |
| Blue-Wire Limited | Professional & scientific | 2001 |
| Bluebear Investments Ltd | Real estate | 2022 |
| Bluebird Property Holdings Limited | Real estate | 2019 |
| Bluerush Limited | Professional & scientific | 2012 |
| Bluewing Media Ltd | Information & communication | 2011 |
| Bmcam Holding Ltd | Financial services | 2018 |
| Boathouse Reach Management Limited | Households | 1989 |
| Bobble Group Limited | Information & communication | 2023 |
| Boldhorn Press Ltd | Wholesale & retail | 2026 |
| Bonusbazar Ltd | Wholesale & retail | 2024 |
| Booktech Ltd | Wholesale & retail | 2017 |
| Boon Advisory Services Limited | Information & communication | 2022 |
| Borlase Henley Ltd | Hospitality | 2017 |
| Boscapo Ltd | Real estate | 2023 |
| Bothhands Limited | Extraterritorial | 2015 |
| Boundless Immersive Limited | Information & communication | 2019 |
| Bournebridge Property Ltd | Real estate | 2021 |
| Boutique Spirits Co Limited | Professional & scientific | 2025 |
| Bowem 2020 Limited | Real estate | 1963 |
| Boyes Management Services Limited | Construction | 2007 |
| Bracknell Glazing and Window Company Limited | Construction | 2017 |
| Bradenham Agricultural and Farming Limited | Arts & recreation | 2014 |
| Brahma Swaroop Ltd | Information & communication | 2016 |
| Bramble England Ltd | Wholesale & retail | 2025 |