| B and M Glazing Limited | Administrative & support | 2002 |
| B B a K Limited | Construction | 2004 |
| B Conected Ltd | Administrative & support | 2025 |
| B I C (GB) Limited | Professional & scientific | 2006 |
| B J Lowry Developments Ltd | Real estate | 2016 |
| B K Food & Wine Ltd | Wholesale & retail | 2015 |
| B K Southall Limited | Hospitality | 2024 |
| B P Hawkins Limited | Administrative & support | 2003 |
| B Patel & Co Ltd | Professional & scientific | 2009 |
| B Patel & Sons Finance Limited | Real estate | 2008 |
| B Patel Properties Limited | Real estate | 2021 |
| B R Sparklingmate Ltd | Wholesale & retail | 2025 |
| B S L Construction Services Ltd | Construction | 2021 |
| B S P Plumbing & Heating Limited | Construction | 2002 |
| B Shah Accountants Ltd | Professional & scientific | 2020 |
| B W Commercial Services Ltd | Real estate | 2019 |
| B&A Group Limited | Administrative & support | 2024 |
| B&B Decorating Solutions Ltd | Construction | 2022 |
| B&C Evergreen Supplies Limited | Hospitality | 2025 |
| B&C Land and New Homes Ltd | Professional & scientific | 2012 |
| B&C Projects Limited | Construction | 2026 |
| B&D Interiors Design Ltd | Construction | 2023 |
| B&G Property Solution Ltd | Construction | 2018 |
| B&G Transport (Tewkesbury) Ltd | Transport & logistics | 2018 |
| B&K Healthy Prep Meals Limited | Hospitality | 2022 |
| B&L Global Services Limited | Professional & scientific | 2006 |
| B&N Properties Development Ltd | Households | 2023 |
| B&P Hospitality Ltd | Hospitality | 2022 |
| B&S Exchange Ltd | Financial services | 2024 |
| B&W the Collection Ltd | Manufacturing | 2021 |
| B-12 Development Ltd | Real estate | 2018 |
| B-E Management Consultancy Ltd | Professional & scientific | 2026 |
| B-Lock Industries Ltd | Professional & scientific | 2013 |
| B. S. K. Construction Limited | Construction | 2001 |
| B. Tiberyu Facilities Ltd | Transport & logistics | 2025 |
| B.A. Build Ltd | Construction | 2016 |
| B.A.A.D. Limited | Health & social care | 1999 |
| B.A.R. Estates Limited | Real estate | 2005 |
| B.C. Byrne & Co Limited | Professional & scientific | 2002 |
| B.Herman Limited | Construction | 2016 |
| B.I Business Investment Ltd | Administrative & support | 2016 |
| B.K.B Tax & Business Services Limited | Professional & scientific | 2025 |
| B.P Homebody Limited | Wholesale & retail | 2020 |
| B12 Project Management Ltd | Construction | 2025 |
| B2 Developers Ltd | Construction | 2025 |
| B20 Birmingham Limited | Construction | 2022 |
| B22 London Ltd | Wholesale & retail | 2025 |
| B2BSALESUK Limited | Construction | 2017 |
| B3 Creative Limited | Arts & recreation | 2005 |
| B4NKD Limited | Information & communication | 2020 |
| B4R Properties Limited | Real estate | 2006 |
| B4UR Limited | Real estate | 2023 |
| BA Construct Services Ltd | Construction | 2024 |
| BA Shaq Ltd | Other services | 2021 |
| BA Taxation Ltd | Professional & scientific | 2011 |
| BAA Holdings Ltd | Wholesale & retail | 2018 |
| Baadshah Lounge Limited | Hospitality | 2019 |
| Baarish Restaurant and Bar Ltd | Hospitality | 2019 |
| Baaz Wholesale Ltd | Transport & logistics | 2022 |
| Baba Holdings Limited | Real estate | 2006 |
| Baba Internet Cafe Ltd | Wholesale & retail | 2018 |
| Baba Sawan Lodge Limited | Real estate | 1995 |
| Baba Trade Ltd | Hospitality | 2025 |
| Babadosa Ltd | Manufacturing | 2024 |
| Babartech Limited | Professional & scientific | 2023 |
| Babel Investments UK Limited | Real estate | 2017 |
| Babicoco Ltd | Wholesale & retail | 2018 |
| Baby Baby Limited | Extraterritorial | 2005 |
| Baby Face Carpentry Ltd | Construction | 2014 |
| Baby G Productions Ltd | Information & communication | 2024 |
| Baby Sensory North Harrow Ltd | Education | 2015 |
| Baby Taxi Ltd | Transport & logistics | 2022 |
| Babylon Academy | Education | 2012 |
| Babylon Re-Developments Limited | Construction | 2014 |
| Babylon Technology Ltd | Wholesale & retail | 2026 |
| Babypipkin Limited | Wholesale & retail | 2021 |
| Bacchus Merchantry Limited | Wholesale & retail | 2018 |
| Bach James Mansour & Company Limited | Professional & scientific | 2024 |
| Bachu Consultancy Ltd | Health & social care | 2025 |
| Back Office Bunny Limited | Professional & scientific | 2017 |
| Back Online Limited | Professional & scientific | 2015 |
| Back to the Beginning Limited | Professional & scientific | 2021 |
| BAD BOY Motorz Ltd | Wholesale & retail | 2019 |
| Badasca Light Limited | Construction | 2025 |
| Badgers Close Freehold Limited | Households | 2004 |
| Badgers Management Limited | Households | 1984 |
| Badhiya Construction Ltd | Construction | 2025 |
| Badzelda Productions Limited | Information & communication | 2019 |
| BAE Enterprises Ltd | Administrative & support | 2016 |
| Bafleh Property Limited | Real estate | 2017 |
| Baga Limited | Real estate | 2006 |
| Bagaso Limited | Real estate | 2015 |
| Bagchi Kotnis and Daughters Ltd | Financial services | 2025 |
| Baggins Holding Limited | Health & social care | 2021 |
| Baghela Limited | Information & communication | 2023 |
| Bagini Ventures Limited | Real estate | 2021 |
| Bahar Fashion Ltd | Wholesale & retail | 2025 |
| Bahara Restaurants Ltd | Hospitality | 2024 |
| Bahari & Mimi Limited | Wholesale & retail | 2017 |
| Bahatimzuri Limited | Real estate | 2023 |