| Bereco Retail Limited | Administrative & support | 2010 |
| Beres Developments Limited | Construction | 2002 |
| Beresford Estate Holdings Limited | Households | 2025 |
| Berg Investments Limited | Financial services | 2009 |
| Berna Transport Ltd | Transport & logistics | 2019 |
| Bernard Services Ltd | Health & social care | 2025 |
| Bernard.Moyo Limited | Health & social care | 2025 |
| Bershaw Ltd | Professional & scientific | 2022 |
| Bespoke Access Solutions Limited | Construction | 2026 |
| Bespoke Chauffeuring Services Ltd | Transport & logistics | 2022 |
| Bespoke Commercial Interiors Limited | Construction | 2016 |
| Bespoke FAB Shop Ltd | Manufacturing | 2024 |
| Bespoke Home & Garden Construction Ltd | Construction | 2024 |
| Bespoke Physiotherapy Ltd | Health & social care | 2023 |
| Bespoke Trade Frames Ltd. | Wholesale & retail | 2023 |
| Bessim Bessim Limited | Transport & logistics | 2024 |
| Best Boozer Limited | Wholesale & retail | 2026 |
| Best Building Ltd | Transport & logistics | 2017 |
| Best Hand Car Wash Attercliffe Limited | Wholesale & retail | 2020 |
| Best United Ltd | Health & social care | 2019 |
| Bestpath Consulting Ltd | Health & social care | 2025 |
| Beststall Ltd | Wholesale & retail | 2014 |
| Beta Engineering Services Ltd | Manufacturing | 2001 |
| Beta Roofing and Cladding Limited | Construction | 2024 |
| Betextra Limited | Arts & recreation | 2010 |
| Better Buy Ltd | Wholesale & retail | 2015 |
| Betterdays Music Ltd | Information & communication | 2026 |
| Bevani Limited | Manufacturing | 2025 |
| Beverly Group Ltd | Administrative & support | 2024 |
| Bews & Fennell Ltd | Professional & scientific | 2026 |
| Beyond Agency Ltd | Professional & scientific | 2019 |
| Beyond Bytes Ltd | Information & communication | 2015 |
| Beyond Reach Consulting Limited | Professional & scientific | 2019 |
| BFK Profit Ltd | Information & communication | 2022 |
| BGB Design Consultancy Limited | Professional & scientific | 2023 |
| Bglad Property Management Ltd | Real estate | 2025 |
| BGP Trading Limited | Wholesale & retail | 2025 |
| BHI Group Limited | Financial services | 2016 |
| Bhullars Property Services Ltd | Real estate | 2017 |
| Bhutta Brothers Ltd | Transport & logistics | 2026 |
| Bibikola Ltd | Transport & logistics | 2018 |
| Bibis Drinks Ltd | Hospitality | 2025 |
| Big BEN Language School Ltd | Education | 2018 |
| Big Daddy's Care Limited | Administrative & support | 2026 |
| Big Fish Clothing (UK) Limited | Wholesale & retail | 2005 |
| Big Guys Limited | Hospitality | 2025 |
| Big Wheel Spins Ltd | Arts & recreation | 2026 |
| Biggiwigs Limited | Wholesale & retail | 2024 |
| Bikeaider Ltd | Wholesale & retail | 2015 |
| Bikebox Alan Ltd | Manufacturing | 2011 |
| Bilder and Lord Enterprises Limited | Hospitality | 2011 |
| Bill NET Security Ltd | Administrative & support | 2020 |
| Billie's Coaches Limited | Professional & scientific | 1949 |
| Billy to Go Ltd | Wholesale & retail | 2026 |
| Billy's J Ltd | Hospitality | 2023 |
| BIM Rigging Services Limited | Information & communication | 2025 |
| Bimok Investments Ltd | Hospitality | 2022 |
| Binarywerks Ltd | Information & communication | 2017 |
| Binden Construction Limited | Real estate | 1984 |
| Binthorpe Properties Ltd | Real estate | 2024 |
| Birch Welding Solutions Limited | Manufacturing | 2023 |
| Birchfield Plumbing & Heating Ltd | Construction | 2024 |
| Birchfield Property Group Ltd | Real estate | 2024 |
| Birchfield Services Ltd | Construction | 2022 |
| Birchfield Total Solutions Ltd | Construction | 2023 |
| Birchwood Estates and Investments Ltd | Real estate | 2026 |
| Birdhouse Tea & Bakes Ltd | Manufacturing | 2025 |
| Birdhouse Tea Company Limited | Manufacturing | 2013 |
| Birksk Limited | Wholesale & retail | 2025 |
| Bismillah Food Store Rotherham Ltd | Wholesale & retail | 2018 |
| Bismillah Kingsway Ltd | Real estate | 2023 |
| Bistro 2 Bisque Ltd | Wholesale & retail | 2025 |
| Bistro Bisque Ltd | Construction | 2022 |
| Bite Digital Ltd | Professional & scientific | 2022 |
| Bite Easy Dental Laboratory Limited | Administrative & support | 2022 |
| Bite Easy Denture Repairs Limited | Administrative & support | 2024 |
| Bizfi Limited | Financial services | 2025 |
| Biztalkers Limited | Information & communication | 2010 |
| Bizzexpress Ltd | Other services | 2025 |
| Bj's VW Custom Restoration Ltd | Wholesale & retail | 2023 |
| BJW Consulting Ltd | Information & communication | 2014 |
| BK Spark (Electrical Services) Ltd | Construction | 2024 |
| BKM Rentals Ltd | Real estate | 2022 |
| Black & Decker Finance | Professional & scientific | 1973 |
| Black & Decker International | Professional & scientific | 1925 |
| Black & Decker International Finance (UK) Limited | Professional & scientific | 2009 |
| Black & Decker International Finance Holdings (UK) Limited | Professional & scientific | 2009 |
| Black & Decker Pension Trustee Limited | Extraterritorial | 1990 |
| Black Hill Engineering Ltd | Construction | 2022 |
| Black Marlin Commercial Ltd | Wholesale & retail | 2021 |
| Black Minority Ethnic Disability Family Network CIC | Other services | 2026 |
| Black Plant & Vehicle Hire Limited | Administrative & support | 2022 |
| Blackett's Transport Ltd | Transport & logistics | 2018 |
| Blackforge Ltd | Wholesale & retail | 2025 |
| Blackfort Equestrian Ltd | Wholesale & retail | 2020 |
| Blackhorn Properties Limited | Real estate | 2009 |
| Blackmoor Foot Inns Ltd | Hospitality | 2022 |
| Blackthorn Land and Estates Limited | Agriculture & fishing | 2026 |
| Bladebest Limited | Manufacturing | 1974 |
| Blaize Merchandise Ltd | Wholesale & retail | 2014 |