| Bono Healthcare Services Ltd | Health & social care | 2024 |
| Bonsoire Bridal Limited | Wholesale & retail | 2022 |
| Bonsoire Prom Limited | Wholesale & retail | 2022 |
| Bony M Ltd | Transport & logistics | 2023 |
| BOO and Bubbles Ltd | Construction | 2023 |
| Boochworx Ltd | Wholesale & retail | 2025 |
| Boofia Ltd | Hospitality | 2025 |
| Booj Ltd | Professional & scientific | 2018 |
| Book Tribe Limited | Wholesale & retail | 2020 |
| Bookishly Limited | Arts & recreation | 2013 |
| Books Accountancy Services Limited | Professional & scientific | 2021 |
| Booksmarts Ltd | Professional & scientific | 2024 |
| Boombastic Events Ltd | Arts & recreation | 2015 |
| Boome & Co Investing Ltd | Administrative & support | 2019 |
| Boomkay Limited | Wholesale & retail | 2023 |
| Boost TA Ltd | Real estate | 2024 |
| Boothville Property Services Limited | Construction | 1996 |
| Boothville Roofing and Construction Limited | Construction | 2010 |
| Boothville Services Limited | Other services | 2024 |
| Booze & Bites Bar Ltd | Hospitality | 2026 |
| Boquita DE Cielo Limited | Professional & scientific | 2023 |
| Bora A2B Ltd | Wholesale & retail | 2020 |
| Borcomo Ltd | Wholesale & retail | 2019 |
| Bordei Limited | Transport & logistics | 2021 |
| Borderless Pathways Ltd | Administrative & support | 2026 |
| Bordylyan Ltd | Transport & logistics | 2016 |
| Boreland CIC | Hospitality | 2025 |
| Boreland Youth Care Ltd | Health & social care | 2024 |
| Borjia Bars Ltd | Hospitality | 2017 |
| Born & Bread Bakery Ltd | Manufacturing | 2018 |
| Born 2 Reform Ltd | Arts & recreation | 2026 |
| Born to Explore Ltd | Health & social care | 2026 |
| Born to Perform Care Services Ltd | Health & social care | 2021 |
| Born to Perform Dance School Ltd | Health & social care | 2020 |
| Born With Horns Tattoo Ltd | Arts & recreation | 2022 |
| Borneo Martell Turner Coulston LLP | | 2007 |
| Bornfree Investments Limited | Manufacturing | 2014 |
| Borough Pizza Limited | Hospitality | 2025 |
| Borough Residential Developments Ltd | Construction | 2016 |
| Borrowbrook Energy Limited | Professional & scientific | 2026 |
| Borta Construction Services Ltd | Construction | 2017 |
| Borzz Ltd | Transport & logistics | 2021 |
| Bosan Studio Ltd | Wholesale & retail | 2025 |
| Bosclad Ltd | Construction | 2008 |
| Bosha Ltd | Transport & logistics | 2024 |
| Boshan Connect Ltd | Real estate | 2025 |
| Boskos Foods Central Ltd | Hospitality | 2021 |
| Boskos Foods Ltd | Hospitality | 2020 |
| Boss (D & B) Limited | Construction | 1998 |
| Bosvision Ltd | Wholesale & retail | 2012 |
| Boswell Living (Investments) Limited | Real estate | 2020 |
| Boswell Living Limited | Real estate | 2015 |
| Botanical Supplies Ltd | Wholesale & retail | 2024 |
| Botnari Ltd | Construction | 2022 |
| Bott the Builder (LB) Limited | Construction | 2006 |
| Bottle IT Ltd | Wholesale & retail | 2022 |
| Bottled Expressions Ltd | Wholesale & retail | 2024 |
| Bottomley Consulting Ltd | Professional & scientific | 2014 |
| Botzen Facilities Management Ltd | Wholesale & retail | 2022 |
| Boucher Farm Barn Limited | Households | 2025 |
| Boudicca Worldwide Ltd | Education | 2021 |
| Boughton Beer Tent Ltd | Hospitality | 2016 |
| Boughton Green Holdings Ltd | Financial services | 2024 |
| Boughton Primary School Trust | Education | 2012 |
| Boughton Tree and Landscapes Ltd | Administrative & support | 2026 |
| Bougie Bians Ltd | Information & communication | 2022 |
| Boul Traders Limited | Other services | 2016 |
| Boulevars Ltd | Wholesale & retail | 2024 |
| Boultbee & Co Limited | Health & social care | 2012 |
| Boulton & Sons Design & Engineering Ltd | Professional & scientific | 2017 |
| Bouncing Bunnies Childcare Ltd | Health & social care | 2025 |
| Bouncy Tech Northants Ltd | Administrative & support | 2025 |
| Boundary Capital Ltd | Professional & scientific | 2009 |
| Bounty Roofing and Building Services Ltd | Construction | 2025 |
| Bourne END Construction Limited | Construction | 2016 |
| Bourton Group LLP | | 2012 |
| Bovingdon Media Ltd | Administrative & support | 2014 |
| Bowden House Management Limited | Households | 1989 |
| Bowers Electrical Engineering Services Limited | Construction | 2014 |
| Bowes Estates Limited | Administrative & support | 2008 |
| Bowler's Yard Management Company Limited | Households | 2017 |
| Bowles Capital Ltd | Real estate | 2022 |
| Bowlsmaster Limited | Manufacturing | 2019 |
| Bowpart Limited | Professional & scientific | 2024 |
| Box Pallets Limited | Administrative & support | 2019 |
| Boxabl Homes Ltd | Real estate | 2025 |
| Boxed Frog Limited | Information & communication | 2012 |
| Boxford Properties Ltd | Real estate | 2021 |
| Boxmoor Aerials Limited | Information & communication | 2023 |
| Boza Removals Ltd | Transport & logistics | 2025 |
| Bozi Transport Ltd | Transport & logistics | 2024 |
| BP Driving Services Limited | Transport & logistics | 2014 |
| BP Fairs Limited | Administrative & support | 2009 |
| Bpjc Properties Limited | Real estate | 2017 |
| BPM Matters Ltd | Information & communication | 2014 |
| BPN Building Services Ltd | Construction | 2021 |
| BR Finance Services Ltd | Professional & scientific | 2026 |
| BR Trans Ltd | Transport & logistics | 2019 |
| Brackley Roofing Ltd | Construction | 2023 |
| Brackmills Auto Care Limited | Wholesale & retail | 2026 |