| B.O.S Car Cosmetics Ltd | Wholesale & retail | 2022 |
| B.R. Plant Engineers Ltd | Manufacturing | 1986 |
| B.S.C. Electrical Limited | Wholesale & retail | 2001 |
| B.T.J.D Property Ltd | Real estate | 2022 |
| B.T.W-R Ltd | Real estate | 2025 |
| B.Z.Betteredge Ltd | Real estate | 2021 |
| B1ST Holdings Ltd | Real estate | 2021 |
| B1ST Property Limited | Financial services | 2025 |
| B1ST Scaffolding Limited | Construction | 2014 |
| B2B Fairs Ltd | Administrative & support | 2023 |
| B3 Building Services Ltd | Construction | 2017 |
| BA Consult Limited | Professional & scientific | 2008 |
| BA Cuts Ltd | Other services | 2025 |
| BA Deep Ltd | Wholesale & retail | 2019 |
| BA Landscapes Ltd | Administrative & support | 2020 |
| Baabss.Uk Ltd | Wholesale & retail | 2023 |
| Baba Shaheed Takhanwadh Ltd | Wholesale & retail | 2025 |
| Baban Medical Services Ltd | Health & social care | 2018 |
| Babba Isher Singh Construction Limited | Construction | 2024 |
| Babbacombe 1967 Limited | Extraterritorial | 2013 |
| Babington Motors,Limited | Real estate | 1937 |
| Babpat Ltd | Health & social care | 2018 |
| Baby and Childrens Market Ltd | Information & communication | 2014 |
| Baby Homes Ltd | Real estate | 2023 |
| Baby People Limited | Arts & recreation | 2007 |
| Baby Property Ltd | Real estate | 2021 |
| Baby Sensory (East Midlands) Limited | Education | 2016 |
| Baby Steps London Ltd | Wholesale & retail | 2023 |
| Baby T Workshops Limited | Education | 2008 |
| Babylon & UK Limited | Wholesale & retail | 2026 |
| BAC Capital Limited | Real estate | 2024 |
| BAC Property Investment Limited | Real estate | 2022 |
| Bacchus Beaurepaire Ltd | Hospitality | 2021 |
| Back and Forth Designs Ltd | Professional & scientific | 2013 |
| Back to Basics Events Ltd | Administrative & support | 2006 |
| Back Yard Bacon Limited | Manufacturing | 2024 |
| Backpack Travels Ltd | Administrative & support | 2024 |
| Backstage Recording Studios Limited | Information & communication | 2000 |
| Backtmr Ltd | Wholesale & retail | 2020 |
| BAD Apple Projects Ltd | Real estate | 2011 |
| BAD BAT Comics Limited | Wholesale & retail | 2025 |
| BAD Byte Software Ltd | Information & communication | 2017 |
| Badgers Corner Ltd | Real estate | 2021 |
| Badgetracker Limited | Information & communication | 2025 |
| Badsey Gardens (Residents) Management Company Limited | Households | 2025 |
| BAG World Limited | | 2003 |
| Bagley & Deane LLP | | 2023 |
| Bagri Investments Limited | Real estate | 2018 |
| Bagri Services Limited | Construction | 2016 |
| Bagzada Store Ltd | Wholesale & retail | 2026 |
| Bahar Construction Limited | Construction | 2025 |
| Bahth Holdings Ltd | Financial services | 2026 |
| Bahth Property Group Ltd | Real estate | 2026 |
| Baig's Meat Shop Ltd | Wholesale & retail | 2024 |
| Bailey & Sons Limited | Manufacturing | 1954 |
| Bailey Construction (Derby) Limited | Construction | 2001 |
| Bailey Earthmoving & Logistics Limited | Construction | 2021 |
| Baines Alsbury Leisure (Derby) Limited | Arts & recreation | 2013 |
| Bains Enterprise Limited | Transport & logistics | 2018 |
| Bains Tyre Services Limited | Wholesale & retail | 2012 |
| Bairavi Ltd | Health & social care | 2024 |
| Baizdon Ltd | Information & communication | 2022 |
| Baiztech Limited | Construction | 2022 |
| Bajwa Brand Ltd | Hospitality | 2026 |
| Bajwa Builder Midland Ltd | Construction | 2020 |
| Bake Derbyshire Ltd | Manufacturing | 2025 |
| Bake Planner Ltd | Information & communication | 2025 |
| Baker and Jahanbani Properties Limited | Real estate | 2023 |
| Baker Engineering Limited | Manufacturing | 2008 |
| Baker Metals Recycling Limited | Wholesale & retail | 2019 |
| Bakerfield Surveying Ltd | Construction | 2014 |
| Bakes Club Ltd | Manufacturing | 2024 |
| Bako Mini Market Ltd | Wholesale & retail | 2019 |
| BAL Construction Limited | Construction | 2012 |
| BAL Grab Ltd | Construction | 2018 |
| BAL Purna Ltd | Real estate | 2026 |
| Balanced Bodies Midlands Ltd | Other services | 2018 |
| Balaton House Developments Limited | Construction | 2015 |
| Balcara Consulting Limited | Professional & scientific | 2007 |
| Balcerhouse Ltd | Real estate | 2026 |
| Balcony London Limited | Wholesale & retail | 2023 |
| Baldwins Grab and Tipper Hire Limited | Transport & logistics | 2018 |
| Balfour Beatty Plant & Fleet Services Limited | Manufacturing | 1989 |
| Balgrac Limited | Wholesale & retail | 2016 |
| Balgrac Tech Ltd | Information & communication | 2021 |
| Balgrac Technology Limited | Professional & scientific | 2024 |
| Bali Aesthetics EB Ltd | Other services | 2025 |
| Bali Beds Derby Limited | Other services | 2024 |
| Balkan Enterprise Ltd | Hospitality | 2017 |
| Ballingho Accountancy Services (UK) Limited | Professional & scientific | 2020 |
| Balloon and Party Ideas Limited | Wholesale & retail | 2016 |
| Balls 2 Marketing Limited | Professional & scientific | 2011 |
| Balls 2 Media Limited | Information & communication | 2024 |
| Balls and Straws Ltd | Hospitality | 2024 |
| Bally Smiles Ltd | Health & social care | 2021 |
| Ballyburn Ltd | Professional & scientific | 2024 |
| Ballycolin Investments Limited | Transport & logistics | 1999 |
| Ballymacsheeran Limited | Wholesale & retail | 2017 |
| Balmaha Limited | Professional & scientific | 2018 |
| Balti Fusion Limited | Hospitality | 2020 |