| Best Air Commercial & Domestic Ltd | Energy | 2021 |
| Best Barber 1 Limited | Other services | 2025 |
| Best Bedford Kebab Ltd | Hospitality | 2023 |
| Best Boba Ltd | Hospitality | 2024 |
| Best Choice Agency Ltd | Administrative & support | 2018 |
| Best Finish Ltd | Construction | 2026 |
| Best Pizza Bedford Food Limited | Hospitality | 2024 |
| Best Pizza Bedford Limited | Hospitality | 2022 |
| Best Served Cold Limited | Information & communication | 2025 |
| Best Value Cars Ltd | Wholesale & retail | 2026 |
| Besthelp Care Limited | Administrative & support | 2023 |
| Besthelp Services Limited | Professional & scientific | 2024 |
| Beta Bookkeeping & Accounts Limited | Professional & scientific | 2023 |
| Beta-Life (UK) Limited | Other services | 1993 |
| Bethenextlink.Co.Uk Limited | Transport & logistics | 2005 |
| Better Abode LLP | | 2018 |
| Better Bodies Ltd | Arts & recreation | 1997 |
| Better Homes Living Ltd | Real estate | 2019 |
| Better Luck Limited | Hospitality | 2026 |
| Better Together Care Ltd | Health & social care | 2021 |
| Bevan & Sons Roofing Services Limited | Construction | 2019 |
| Beverly's Boutique Ltd | Wholesale & retail | 2021 |
| Bevsi Limited | Wholesale & retail | 2019 |
| Beyhealth UK Ltd | Health & social care | 2011 |
| Beyond Detention | Other services | 2011 |
| Beyond Robotix Ltd | Professional & scientific | 2024 |
| BFG Electrical Ltd | Construction | 2026 |
| BFS Contractors Limited | Construction | 2011 |
| BFS Member Services Limited | Financial services | 1999 |
| Bfwh 14 Ltd | Construction | 2026 |
| BG Blueprint Ltd | Education | 2019 |
| BG Logistics Ltd | Transport & logistics | 2018 |
| BG Transport Northants Ltd | Transport & logistics | 2024 |
| BGF Accounts & Protection Ltd | Financial services | 2020 |
| Bgfpreservation Limited | Real estate | 2014 |
| BGG Property Limited | Real estate | 2025 |
| BGG Property Management Limited | Real estate | 2025 |
| Bggs Properties Ltd | Real estate | 2024 |
| Bgis Trading Ltd | Real estate | 2026 |
| Bgsr Consultants Limited | Real estate | 2007 |
| BGW Electrical Services Ltd | Construction | 2025 |
| Bhagya Property Investments Ltd | Real estate | 2017 |
| Bharaj Properties Limited | Real estate | 2006 |
| Bharaj & SON Oak Limited | Real estate | 2005 |
| Bharun Inc Ltd | Real estate | 2021 |
| Bhatt Ventures Ltd | Real estate | 2025 |
| BHR Group Limited | Administrative & support | 2019 |
| Bianchi Cycling UK Ltd | Wholesale & retail | 1972 |
| Bianco Academy Ltd | Education | 2021 |
| Bianco Beauty Ltd | Other services | 2016 |
| Bibe Construction Ltd | Construction | 2024 |
| Bibi Care 4 U Ltd | Health & social care | 2024 |
| Bibimh Ltd | Real estate | 2022 |
| Bibre Construction Ltd | Construction | 2021 |
| Bickels Cafe Ltd | Hospitality | 2022 |
| BID & Tender Support Limited | Administrative & support | 2014 |
| Biddenham Development Ltd | Real estate | 2020 |
| Biddenham Golf Club Limited | Real estate | 1997 |
| Biddenham Grange Management Limited | Real estate | 2005 |
| Bidology Consulting Ltd | Professional & scientific | 2021 |
| Big Blue Skies Ltd | Information & communication | 2005 |
| Big Boss Film Productions Ltd | Information & communication | 2025 |
| Big Cat Coma Ltd | Hospitality | 2017 |
| Big Iron Ltd | Professional & scientific | 2025 |
| Big Kidneys Limited | Information & communication | 2002 |
| Bigbargains Ltd | Wholesale & retail | 2025 |
| Bilbeny Bespoke Ltd | Manufacturing | 2021 |
| Bill the Bone Rigging Services Ltd | Information & communication | 2015 |
| Billa International Market Ltd | Wholesale & retail | 2018 |
| Billing Waters(Northampton)Limited | Real estate | 1967 |
| Billingsmoor Farm Limited | Agriculture & fishing | 2011 |
| Billington & Lawrence Limited | Construction | 2003 |
| Billy Yates Music Ltd | Arts & recreation | 2024 |
| Bims Group Limited | Professional & scientific | 2025 |
| Bimzer Consult Limited | Health & social care | 2014 |
| Bimzer Properties C.I.C. | Real estate | 2024 |
| Binary Titan Consulting Limited | Information & communication | 2015 |
| Binary Titan Limited | Information & communication | 2012 |
| Bind Advisory Ltd. | Professional & scientific | 2022 |
| Bind London Ltd | Wholesale & retail | 2019 |
| Binet Beauty Limited | Wholesale & retail | 2020 |
| Bingey Welding Limited | Construction | 2015 |
| Binky Nixon Limited | Professional & scientific | 2011 |
| Binky Nixon Photography Limited | Arts & recreation | 2018 |
| Binodini Ltd | Wholesale & retail | 2023 |
| Bintbladi UK Limited | Wholesale & retail | 2021 |
| Biogen EM Holdco Limited | Financial services | 2017 |
| Biogen EM Limited | Financial services | 2017 |
| Biogen EM Midco Limited | Extraterritorial | 2017 |
| Biogen EM Opco Limited | Energy | 2013 |
| Biogen EM Topco Limited | Extraterritorial | 2017 |
| Biogen Haulage Limited | Transport & logistics | 2026 |
| Biogen Holdings Limited | Extraterritorial | 2012 |
| Bioglot Ventures Ltd | Administrative & support | 2020 |
| Biosystem Laboratories Limited | Professional & scientific | 2012 |
| Biowatt Biogas Limited | Administrative & support | 2017 |
| Biowatt Developments Limited | Other services | 2011 |
| Biowatt Energy Limited | Other services | 2016 |
| Biowatt Limited | Extraterritorial | 2012 |
| Birch & SON Ltd | Construction | 2011 |