| Begemi Limited | Hospitality | 2025 |
| Bellannette Ltd | Wholesale & retail | 2023 |
| Bellway Coalville Management Limited | Real estate | 2012 |
| Belton Cars Ltd | Other services | 2008 |
| Belvoir 75-81 Ltd | Construction | 2024 |
| Belvoir Express Limited | Wholesale & retail | 2024 |
| Belvoir Travel Ltd | Transport & logistics | 2025 |
| Berries & Bakes Ltd | Wholesale & retail | 2024 |
| Berrington Court Limited | Households | 2021 |
| Besblock Limited | Extraterritorial | 1972 |
| Bespoke Menu Solutions Limited | Manufacturing | 2007 |
| Betteridge Windows & Doors Ltd | Other services | 2017 |
| BEU Group Limited | Health & social care | 2015 |
| Bevex Limited | Manufacturing | 2003 |
| Beyond Beauty Artistry Limited | Other services | 2015 |
| BFM Agncy Ltd | Professional & scientific | 2025 |
| Biera Garage Ltd | Wholesale & retail | 2023 |
| Big HIT Ltd | Wholesale & retail | 2023 |
| Big Wheel Drive 2 Ltd | Transport & logistics | 2026 |
| Big Wheel Drive Ltd | Transport & logistics | 2016 |
| Bilby School UK Limited | Education | 2013 |
| BIO Break Ltd | Manufacturing | 2025 |
| Birch Bedrooms Limited | Manufacturing | 1996 |
| Birch Fitted Furniture Limited | Financial services | 2006 |
| Birchall Gardens LLP | | 2015 |
| Birmingham Gold Ltd | Wholesale & retail | 2023 |
| Birthworld CIC | Education | 2021 |
| Bitter and Twisted Micro PUB Ltd | Hospitality | 2019 |
| Black 555 Ltd | Wholesale & retail | 2024 |
| Black Barn Design Limited | Wholesale & retail | 2025 |
| Blackboard Deals Ltd | Information & communication | 2026 |
| Blackford Commercial Ltd | Professional & scientific | 2026 |
| Blackhorse Road Properties LLP | | 2019 |
| Blackhorse View Energy Centre Management Company Limited | Households | 2020 |
| Blackwood Fabrications Ltd | Manufacturing | 2022 |
| Blakes Bedrooms Limited | Construction | 2004 |
| Blink Creative Services Ltd | Professional & scientific | 2026 |
| Bllq LLP | | 2016 |
| BLLQ2 Limited | Construction | 2019 |
| Bloomin' Gardens and Landscapes Limited | Administrative & support | 2003 |
| Blossoms Boutique Ltd | Wholesale & retail | 2026 |
| BLU Bell Services Ltd | Construction | 2023 |
| BLU Nova Trading Ltd | Financial services | 2025 |
| Blue Giant Studios Ltd | Professional & scientific | 2021 |
| Blue Ribbon Homes Limited | Administrative & support | 2007 |
| Bluuu Limited | Professional & scientific | 2007 |
| BLW Investments Ltd | Real estate | 2024 |
| Bmstransport Ltd | Transport & logistics | 2020 |
| BOARD24 Ltd | Administrative & support | 1987 |
| Boards Online Limited | Other services | 2016 |
| Bolabode Consulting & Media Ltd | Professional & scientific | 2026 |
| Bollo Lane LLP | | 2024 |
| Bond Street Garage Hinckley Limited | Wholesale & retail | 2018 |
| Bork Services Limited | Administrative & support | 2024 |
| Borthwick's Property Investors Ltd. | Real estate | 2020 |
| Bosa Pubs Ltd | Hospitality | 2025 |
| Boulthole Studio Ltd | Professional & scientific | 2025 |
| Bowden Financial Consultancy Ltd | Financial services | 2019 |
| Bowmer Engineering and Management Limited | Extraterritorial | 2017 |
| Boxwise Packaging Solutions Limited | Administrative & support | 2016 |
| Bradgate Development Services Limited | Construction | 1980 |
| Bradgate Employees Trustee Limited | Financial services | 2023 |
| Bradgate Surveys Limited | Construction | 2026 |
| Bradgate Transport Ltd | Transport & logistics | 2020 |
| Bramatt Computing Ltd | Information & communication | 2007 |
| Branston Group Ltd | Extraterritorial | 2020 |
| Breaston Consulting Ltd | Financial services | 2015 |
| Breaston Financial Consulting Ltd | Professional & scientific | 2019 |
| Brickhill Innovation Ltd | Professional & scientific | 2026 |
| Bridge Brewing Co Ltd | Wholesale & retail | 2014 |
| Bright (Hotels) Limited | Hospitality | 2016 |
| Brilliant Consulting and Training Ltd | Public administration | 2024 |
| Britannia Decor Ltd | Construction | 2005 |
| Broad Oak Homes Limited | Construction | 1989 |
| Brock Allen Ltd | Public administration | 2025 |
| Brome GAS Services Ltd | Construction | 2026 |
| Brome Homes Ltd | Real estate | 2024 |
| Bromill Ltd | Professional & scientific | 2022 |
| Bromley Lettings Ltd | Real estate | 2025 |
| Brooklands Milton Keynes LLP | | 2014 |
| Broomleys Joinery Ltd | Construction | 2012 |
| Brown & Sons Events Ltd | Other services | 2025 |
| Brown Stone Bistro Limited | Hospitality | 2019 |
| Brown Street Property Ltd | Real estate | 2026 |
| Brown Sugar Desserts Limited | Wholesale & retail | 2018 |
| BRP UK Ltd | Other services | 2005 |
| Brumor (East Midlands) Limited | Real estate | 2018 |
| Bryant Housing Limited | Real estate | 2025 |
| BSG Logistics Limited | Transport & logistics | 2011 |
| BTL Residential Ltd | Real estate | 2025 |
| BTR Sealing Systems (UK) Limited | Manufacturing | 1927 |
| Bubo Consulting Services Limited | Professional & scientific | 2016 |
| Buds Floral (Leicester) Designs Limited | Wholesale & retail | 2024 |
| Building Material Shop Ltd | Wholesale & retail | 2019 |
| Burgundy Sky UK Ltd | Construction | 2015 |
| BUS and Plant Glass Ltd | Wholesale & retail | 2009 |
| Butterfly's Pre-School Ltd | Health & social care | 2022 |
| Buyrite Enterprises Limited | Manufacturing | 2014 |
| Buyrite Holdings Limited | Financial services | 2019 |
| BV Pharmaserve Limited | Professional & scientific | 2011 |