| Bariot Submission Fighting Ltd | Arts & recreation | 2025 |
| Barking Brains Limited | Health & social care | 2019 |
| Barnwell Estates Limited | Real estate | 2003 |
| Baronie UK Limited | Manufacturing | 2015 |
| Barry Grewcock & Sons Limited | Wholesale & retail | 2002 |
| Barry Grewcock Holdings Limited | Financial services | 2011 |
| Bart Pro Renovations Ltd | Construction | 2026 |
| Barton Site Services Limited | Manufacturing | 2021 |
| Baruchatah Limited | Professional & scientific | 2015 |
| Bary Transport Ltd | Transport & logistics | 2025 |
| BAS Driving Services Limited | Transport & logistics | 2021 |
| Baseobs Care Ltd | Health & social care | 2014 |
| Basha Cleaning Ltd | Other services | 2021 |
| Bateau Grande Vitesse Holdings Limited | Transport & logistics | 2013 |
| Batir Construct Limited | Construction | 2024 |
| Batuhan Worldwide Limited | Wholesale & retail | 2025 |
| Bavi Transport Ltd | Transport & logistics | 2026 |
| Bayram Fishmonger Ltd | Wholesale & retail | 2026 |
| Bbmv Limited | Other services | 2024 |
| BC Electrical Energy Solutions Limited | Construction | 2016 |
| BCH Loading Systems Limited | Professional & scientific | 2021 |
| BCM Recoveries Ltd | Information & communication | 2025 |
| Bcp.Ai Ltd | Real estate | 2024 |
| BD Complyco Ltd | Professional & scientific | 2025 |
| BD Hardware Limited | Wholesale & retail | 2026 |
| BD Technical Polymer Limited | Manufacturing | 1982 |
| BDL Paint Ltd | Construction | 2023 |
| BEA Garden UK Ltd | Wholesale & retail | 2021 |
| Beabells Limited | Administrative & support | 2024 |
| Beambright Ltd | Wholesale & retail | 2024 |
| Bean to Bowl Ltd | Hospitality | 2026 |
| Beanfield Stores Ltd | Wholesale & retail | 2020 |
| Beaton Legacy Ltd | Real estate | 2021 |
| Beaumont Ridge Limited | Financial services | 2025 |
| Beauty Sells Limited | Wholesale & retail | 2023 |
| Beckendale Ltd | Construction | 2023 |
| BED Electrical Group Limited | Financial services | 2023 |
| Beda Technology Limited | Manufacturing | 1987 |
| Bedew Skin Ltd | Wholesale & retail | 2020 |
| Beelaw Ltd | Professional & scientific | 2025 |
| Beetle Garage Corby Ltd | Wholesale & retail | 2024 |
| Beevenon.Ch Limited | Wholesale & retail | 2018 |
| Beever Haulage Limited | Transport & logistics | 2007 |
| Beheton Ltd | Financial services | 2018 |
| Bemacs (Electrical) Limited | Energy | 2004 |
| Benjamin Tate Design Ltd | Manufacturing | 2024 |
| Beresford Embedded Software Limited | Information & communication | 2025 |
| Bergerac Wineries Limited | Agriculture & fishing | 2010 |
| Berkshire Bins Limited | Water & waste | 2025 |
| Berna Food Ltd | Hospitality | 2025 |
| Bernice's Estates Ltd | Real estate | 2020 |
| Berry Global International Holdings Limited | Financial services | 2019 |
| Berry Global UK Holding Limited | Financial services | 2019 |
| Berry UK Containers Limited | Manufacturing | 2022 |
| Berry UK Holdings Limited | Financial services | 2019 |
| Berry UK Pension Trustees Limited | Extraterritorial | 2011 |
| Berto's Bistro Ltd | Hospitality | 2019 |
| Bespoke Bowtique Ltd | Wholesale & retail | 2020 |
| Best Consult US Limited | Information & communication | 2002 |
| Best CUT Turkish Barber Limited | Other services | 2021 |
| Best People Recruit UK Limited | Administrative & support | 2024 |
| Bestmasker Limited | Other services | 2025 |
| Bethel Cares (PVT) Ltd | Health & social care | 2017 |
| Betta Transport Ltd | Transport & logistics | 2024 |
| Bewiched Holdings Limited | Financial services | 2021 |
| Bewiched Limited | Wholesale & retail | 2010 |
| Bewiched Logistics Limited | Manufacturing | 2017 |
| BFB Holdings Limited | Professional & scientific | 2008 |
| BFB Properties Limited | Professional & scientific | 2008 |
| Bfsd Ltd | Administrative & support | 2015 |
| BG Care and Support Services Ltd | Health & social care | 2017 |
| BGG Ventures Limited | Information & communication | 2022 |
| BGS Corby Limited | Professional & scientific | 2017 |
| BGV Marine Limited | Transport & logistics | 2011 |
| Bhavani Venture Ltd | Wholesale & retail | 2021 |
| Bhavya Property Investment Ltd | Real estate | 2022 |
| Biabosca Limited | Transport & logistics | 2010 |
| Bibi Dinu Ltd | Transport & logistics | 2024 |
| Bici Construction Services (BCS) Ltd | Construction | 2023 |
| Bigbacks Ltd | Hospitality | 2026 |
| Biggin Limited | Agriculture & fishing | 2005 |
| Biggs Results Limited | Professional & scientific | 2024 |
| Bike Recycle Limited | Wholesale & retail | 2017 |
| Billy Tazvitya Kamambo Ltd | Professional & scientific | 2025 |
| Billys Garden Services Ltd | Administrative & support | 2022 |
| BIN IT to WIN IT Ltd | Water & waste | 2026 |
| BINIEK88 Limited | Wholesale & retail | 2017 |
| Biniu Ltd | Wholesale & retail | 2016 |
| BIO Icecream Ltd | Manufacturing | 2018 |
| BKW Recruitment Ltd | Administrative & support | 2025 |
| Black Label Insight Limited | Wholesale & retail | 2016 |
| Blackline Studio Detailing Ltd | Wholesale & retail | 2026 |
| Blady Trans Ltd | Transport & logistics | 2019 |
| Blaga Aotomotive and Food Limited | Wholesale & retail | 2024 |
| Blanksim Ltd | Wholesale & retail | 2025 |
| Blaston & District Agricultural Show Society | Other services | 2009 |
| Blessings Childcare Services Limited | Health & social care | 2021 |
| Bliss Hub CIC | Other services | 2025 |
| BLJ Property Investments Ltd | Extraterritorial | 2022 |
| Block Games Limited | Information & communication | 2021 |