| B.R.O Developments Limited | Construction | 2022 |
| B.S. Engineering Ltd. | Manufacturing | 1989 |
| B.S. Specialist Products Limited | Wholesale & retail | 1995 |
| B1 Foundation | Health & social care | 2019 |
| B10 Cleaning Ltd | Administrative & support | 2023 |
| B2B Bars Limited | Hospitality | 2023 |
| B2B Events Limited | Education | 2017 |
| B2BOPTIMAL Ltd | Professional & scientific | 2024 |
| B2C Direct Limited | Wholesale & retail | 2021 |
| B2S Limited | Construction | 2021 |
| B3 Cricket (International) Limited | Manufacturing | 2014 |
| B3 Residential Investments Limited | Real estate | 2021 |
| B33 Trained Ltd | Administrative & support | 2020 |
| B4D Vehicle Hire Ltd | Administrative & support | 2025 |
| B5 Marketing Ltd | Administrative & support | 2025 |
| BA Jewellery Limited | Wholesale & retail | 2025 |
| BA OT Services Ltd | Public administration | 2021 |
| BA Property Maintenance Builder Ltd | Construction | 2025 |
| Ba-Mart Technologies Limited | Information & communication | 2019 |
| Baaz Travel Ltd | Administrative & support | 2022 |
| Baba Choudhry and Sons Ltd | Hospitality | 2025 |
| Baba Dough Ltd | Hospitality | 2021 |
| Baba Restaurant Ltd | Hospitality | 2024 |
| Babar Khan and Co Ltd | Wholesale & retail | 2025 |
| Babbington Estates Ltd | Construction | 2022 |
| Babbington Properties Limited | Real estate | 2020 |
| Babbl Limited | Professional & scientific | 2017 |
| Babeola Limited | Construction | 2024 |
| Baboon Creative Industries Limited | Administrative & support | 2006 |
| Babul Miah Ltd | Financial services | 2025 |
| Baby & Nursery World Ltd | Wholesale & retail | 2024 |
| Baby BIB Company Ltd | Manufacturing | 2018 |
| Baby Broth Ltd | Manufacturing | 2025 |
| Baby Potato Limited | Agriculture & fishing | 2023 |
| Baby Sparks Central Notts Ltd | Education | 2025 |
| Baby Sparks Nottinghamshire East Newark and Melton Limited | Education | 2023 |
| Baby's 1ST Studio Ltd | Professional & scientific | 2022 |
| Babyballet Loughborough, Long Eaton, Melton Mowbray Ltd | Education | 2022 |
| Babygurl Ltd | Wholesale & retail | 2020 |
| Babylon Desserts Ltd | Hospitality | 2024 |
| Babylon Market Ltd | Wholesale & retail | 2021 |
| Babystart Ltd | Wholesale & retail | 2009 |
| Babz Tech Ltd | Wholesale & retail | 2014 |
| BAC IT Systems Ltd | Information & communication | 2013 |
| BAC Lettings Ltd | Real estate | 2025 |
| Bac-Cel Ltd | Professional & scientific | 2024 |
| Bac-In C.I.C. | Health & social care | 2007 |
| Bachent Trading Ltd | Extraterritorial | 2022 |
| Back Forty Property Limited | Real estate | 2014 |
| Back to the Future VMX Ltd | Wholesale & retail | 2010 |
| Back-A-Yard Cuisine & Reenie’S Dumplings Ltd | Hospitality | 2025 |
| Backlit Ltd | Arts & recreation | 2012 |
| BAD Apple Films Ltd | Wholesale & retail | 2026 |
| BAD Beauty Ltd | Other services | 2015 |
| BAD Betty Press Limited | Information & communication | 2019 |
| Badbadbad Records Limited | Information & communication | 2025 |
| Badea Logistics Ltd | Transport & logistics | 2026 |
| Badga Ltd | Transport & logistics | 2018 |
| Badger Project Consulting Limited | Information & communication | 2013 |
| Badger Software Limited | Information & communication | 1994 |
| Badgers Asset Management Ltd | Professional & scientific | 2023 |
| Badgers Basket Ltd | Wholesale & retail | 2014 |
| Badgersound Limited | Wholesale & retail | 2024 |
| Badhe Limited | Health & social care | 2012 |
| Badhe Medical Services Limited | Health & social care | 2016 |
| Badshah's Facilities Limited | Wholesale & retail | 2025 |
| BAE Commercial Limited | Professional & scientific | 2026 |
| BAE Fire-Security-Electrical Ltd | Construction | 2024 |
| Baffa Limited | Financial services | 2026 |
| Bage Technologies Limited | Professional & scientific | 2019 |
| Bagga Ltd | Manufacturing | 2019 |
| Baggaley & Jenkins Limited | Wholesale & retail | 1981 |
| Bagh Hussain & Sons Ltd | Wholesale & retail | 2020 |
| Bagley UK Ltd | Construction | 2006 |
| Bags by Colours of Fashion Ltd | Wholesale & retail | 2022 |
| Bagthisdeal Ltd | Wholesale & retail | 2023 |
| Bagtoad Limited | Real estate | 2019 |
| Bagus Muljadi Ltd | Extraterritorial | 2022 |
| BAH BAH Mezze Ltd | Hospitality | 2023 |
| Bahame Group Ltd | Financial services | 2025 |
| Bahawal Ltd | Transport & logistics | 2023 |
| Bahia Yoga Limited | Health & social care | 2011 |
| Bahri Environmental Solutions Ltd | Professional & scientific | 2026 |
| Baibel Technologies Limited | Information & communication | 2015 |
| Bailey Concepts Limited | Information & communication | 2022 |
| Bailey Smalley Accountants Ltd | Professional & scientific | 2024 |
| Baileydog Ltd | Hospitality | 2024 |
| Baileys Hair Design Limited | Other services | 2005 |
| Bailfarm Limited | Construction | 1978 |
| Bailiz Limited | Professional & scientific | 2011 |
| Baillie Developments Ltd | Construction | 2026 |
| Baily Thomas Provident Trustee Limited | Professional & scientific | 2018 |
| Bains Property Developments Limited | Construction | 2018 |
| Bairava Traders Limited | Wholesale & retail | 2025 |
| Bairuha Tech Ltd | Information & communication | 2025 |
| Baitfella Ltd | Professional & scientific | 2020 |
| BAJ Care Service Limited | Health & social care | 2019 |
| Bajoom Ltd | Professional & scientific | 2019 |
| Bake OFF UK Limited | Wholesale & retail | 2004 |
| BAKE2023 Limited | Professional & scientific | 2023 |