| Beamon Ltd | Professional & scientific | 2013 |
| Bear and Mabel Ltd | Health & social care | 2023 |
| Beards Financial Services Ltd | Professional & scientific | 2023 |
| Beauchene Ltd | Real estate | 2024 |
| Beauholdco Limited | Financial services | 2021 |
| Beaute by Agita Ltd | Other services | 2018 |
| Beautebox Limited | Wholesale & retail | 2021 |
| Beauty Omega Ltd | Other services | 2021 |
| BEC Property Management Ltd | Real estate | 2025 |
| Becksy Ltd | Other services | 2025 |
| BED Mondays Ltd | Arts & recreation | 2019 |
| Bedford Crane Hire Ltd | Administrative & support | 2008 |
| BEE Crafty Ltd | Arts & recreation | 2011 |
| Beer of Houghton Limited | Wholesale & retail | 2015 |
| Beforetree Limited | Administrative & support | 2023 |
| Behagg Contracting Limited | Agriculture & fishing | 2011 |
| Being Cloud Ltd | Information & communication | 2018 |
| Bellevue Construction Services Limited | Construction | 2005 |
| Bells and Peppers Indian Cuisine Ltd | Hospitality | 2024 |
| Bells of Huntingdon Ltd | Hospitality | 2020 |
| Bellys Afro Foods Ltd | Hospitality | 2024 |
| Bema Sports Company Limited | Wholesale & retail | 1989 |
| BEN & Co Construction Limited | Construction | 2005 |
| BEN Franklin Ltd | Information & communication | 2013 |
| Benamcare Ltd | Transport & logistics | 2025 |
| Benchmark Services Limited | Administrative & support | 2001 |
| Bene Homes Ltd | Construction | 2022 |
| Benedict Frederick Ltd | Arts & recreation | 2025 |
| Bennetts at the Green MAN Limited | Administrative & support | 2009 |
| Benson Connect Cars Ltd | Wholesale & retail | 2024 |
| Benstead Limited | Households | 2024 |
| Bentes Private Hire Ltd | Transport & logistics | 2026 |
| Bentley Close Properties Limited | Administrative & support | 2022 |
| Bentwood Investments Limited | Real estate | 2021 |
| Beny Luis Music Ltd | Information & communication | 2025 |
| Berenewed Ltd | Construction | 2024 |
| Best Pet Products Online Limited | Wholesale & retail | 2019 |
| Best Wishes Trading Limited | Wholesale & retail | 2022 |
| Between the Lines Shutters Ltd | Construction | 2020 |
| BH Doors & Engineering Limited | Construction | 2009 |
| Bhalla Petroleum Limited | Wholesale & retail | 2020 |
| BHE Investments Ltd | Real estate | 2009 |
| BHM Property Refurbishments Limited | Construction | 2024 |
| Biantol Transport Ltd | Transport & logistics | 2022 |
| Bibi Driving Ltd | Transport & logistics | 2018 |
| BID Huntingdon Ltd | Administrative & support | 2004 |
| Big Instore Ltd | Wholesale & retail | 2026 |
| Big J Homes UK Ltd | Construction | 2024 |
| Big J Technologies Limited | Information & communication | 2025 |
| Big T Fast Food Ltd | Wholesale & retail | 2025 |
| Big T Media Ltd | Information & communication | 2025 |
| Bigbarn C.I.C. | Information & communication | 2000 |
| Bigj International Ltd | Information & communication | 2019 |
| Bilal Barbers Limited | Other services | 2019 |
| Billcole Haulage (Stevenage) Limited | Transport & logistics | 1974 |
| Biltechsolutions Limited | Information & communication | 2015 |
| Bingo Wonderland Ltd | Arts & recreation | 2022 |
| Biochar Manufacturing Ltd | Manufacturing | 2024 |
| Biodiversity Land Ltd | Extraterritorial | 2024 |
| Biosafe Asbestos Solutions Ltd | Water & waste | 2026 |
| Birch's Leisure Parks Limited | Hospitality | 2016 |
| Biryanibroz Ltd | Hospitality | 2026 |
| Bisecorp Group Ltd | Transport & logistics | 2022 |
| Bitmuseum Limited | Extraterritorial | 2015 |
| BK Houses Ltd | Real estate | 2025 |
| BL Investco Limited | Financial services | 2024 |
| BL Propco Limited | Real estate | 2023 |
| Black Dog Momentum Ltd | Professional & scientific | 2022 |
| Blackberry Stone Ltd | Information & communication | 2022 |
| Blackbuck Ltd | Professional & scientific | 2016 |
| Blackjack Surface Technology Limited | Wholesale & retail | 2010 |
| Blacksmith Customs Limited | Wholesale & retail | 2020 |
| Blades of Glory Lawn Care Ltd | Administrative & support | 2022 |
| Blaire C. Fraser Limited | Manufacturing | 2017 |
| Blake Leahy Ltd | Administrative & support | 2025 |
| Blended Logic Limited | Information & communication | 2015 |
| Blendingmind UK Ltd | Education | 2026 |
| Bletsoe BNG Limited | Agriculture & fishing | 2023 |
| Bliss Beauty Salon Ltd. | Administrative & support | 2011 |
| Bloom in Motion Ltd | Information & communication | 2019 |
| Bloomfield & Gladstone Ltd | Real estate | 2026 |
| Blucom Services Ltd | Information & communication | 2022 |
| Blue Cedar Projects Limited | Administrative & support | 2025 |
| Blue Goose Properties Ltd | Real estate | 2019 |
| Blue Hive Developments Ltd | Real estate | 2022 |
| Blue Horizon Advisory Limited | Information & communication | 2025 |
| Blue Octopus Digital Ltd | Professional & scientific | 2024 |
| Blue Plumbing and Heating Ltd | Construction | 2023 |
| Blue RIO Ltd | Financial services | 2020 |
| Blueblancmange Limited | Wholesale & retail | 2010 |
| Blueflame Heating Limited | Construction | 2001 |
| Bluepointer Services Ltd | Wholesale & retail | 2022 |
| Bluntishamtradionalbutcher Limited | Wholesale & retail | 2025 |
| Blushing Bromeliad Limited | Wholesale & retail | 2025 |
| BMS Heavy Cranes UK Limited | Construction | 2020 |
| BND Property Services Limited | Wholesale & retail | 2007 |
| BNM Cars Ltd | Transport & logistics | 2024 |
| Board Electrical Ltd | Construction | 2018 |
| Boat-Stuff Ltd | Wholesale & retail | 2025 |
| BOB Widd Associates Limited | Administrative & support | 2011 |