| Blyth Properties Limited | Real estate | 2003 |
| Blythmore Limited | Professional & scientific | 1999 |
| BM Haulage Ltd | Transport & logistics | 2023 |
| BM Kitchen Coffee Ltd | Hospitality | 2026 |
| BM Law Ltd | Professional & scientific | 2018 |
| BMD Autos Limited | Wholesale & retail | 2023 |
| BMD Trans UK Ltd | Transport & logistics | 2015 |
| Bme(Black and Minority Ethnic) United Doncaster Ltd | Administrative & support | 2018 |
| BMG Group Holdings Limited | Manufacturing | 2023 |
| BML Catering Ltd | Hospitality | 2025 |
| BMS Motor Salvage Ltd | Wholesale & retail | 2019 |
| BMT Harworth Ltd | Wholesale & retail | 2023 |
| BN Inspections Ltd | Professional & scientific | 2022 |
| BNG Transport Ltd | Transport & logistics | 2025 |
| Bnpz Limited | Wholesale & retail | 2026 |
| BNT Property Investments Limited | Real estate | 2023 |
| Boah Property Ltd | Real estate | 2024 |
| BOB Chellios Ltd | Transport & logistics | 2018 |
| BOB on Flooring Ltd | Construction | 2021 |
| Bobas Logistics Limited | Transport & logistics | 2024 |
| Bobble Car Wash Limited | Wholesale & retail | 2021 |
| Bobby Bake 1 Ltd | Hospitality | 2026 |
| Bobby Bake Ltd | Hospitality | 2026 |
| Bobo Manea 81 Ltd | Transport & logistics | 2025 |
| BOC Courier Ltd | Transport & logistics | 2022 |
| Boderman Limited | Information & communication | 2011 |
| Bodhi Ventures Limited | Real estate | 2024 |
| Bodies Limited | Other services | 1995 |
| Bodrum Cafe & Bar Ltd | Arts & recreation | 2025 |
| Body-Mind DOC Ltd | Health & social care | 2021 |
| Bodyadvance Ltd | Health & social care | 2025 |
| Bodyworx Carr Hill Ltd | Wholesale & retail | 2023 |
| Bogs to Hobs Ltd | Construction | 2025 |
| Bogsim Driving Ltd | Transport & logistics | 2025 |
| Boilers Done Right Ltd | Construction | 2026 |
| Boldify Limited | Wholesale & retail | 2024 |
| Boldline Strategies Ltd | Information & communication | 2026 |
| Bolland Family Investments Limited | Hospitality | 2017 |
| Bolland Plant & Recycling Limited | Administrative & support | 2017 |
| Bolle Ltd | Professional & scientific | 2026 |
| Bolwell Court Management Company Limited | Households | 2025 |
| Bombay Night (Skellow) Limited | Hospitality | 2023 |
| Bomoni Invest Ltd | Professional & scientific | 2022 |
| Bomoni Ltd | Professional & scientific | 2018 |
| Bond Steed Limited | Other services | 2016 |
| Bonded Laminates Woodtape Limited | Professional & scientific | 1959 |
| Bondhay Events & Hospitality Ltd | Hospitality | 2024 |
| Bondhay Golf Club Ltd | Arts & recreation | 2023 |
| Bone Idle Lounge Ltd | Hospitality | 2021 |
| Bones Ultrasound and Grooming Limited | Hospitality | 2019 |
| Bonusbull Ltd | Professional & scientific | 2026 |
| Booker Hart Limited | Real estate | 1964 |
| Booker Print House Ltd | Arts & recreation | 2018 |
| Bookie Brothers Limited | Hospitality | 2019 |
| Bools & Co Limited | Manufacturing | 2024 |
| Boomer Traffic Management Ltd | Construction | 2024 |
| Boomtic Records Ltd | Information & communication | 2012 |
| Boora Retail Limited | Wholesale & retail | 2023 |
| Boosterschool Limited | Education | 2026 |
| Boosting Energy Ltd | Wholesale & retail | 2024 |
| Booth FS Group Ltd | Financial services | 2025 |
| Booth Pipework Services Ltd | Construction | 2026 |
| Bootham Builders Limited | Construction | 2012 |
| Boran Estate Limited | Real estate | 2021 |
| Boreworx Ltd | Construction | 2022 |
| Borkowski Services Ltd | Administrative & support | 2024 |
| Bormar Ltd | Wholesale & retail | 2025 |
| Boromaruk Ltd | Wholesale & retail | 2025 |
| Borough (Operations) Ltd | Real estate | 2019 |
| Boroughbridge Marina Limited | Other services | 2006 |
| Borrelli Capital Limited | Professional & scientific | 2006 |
| Borrill Health Care Ltd | Health & social care | 2023 |
| Borusiak Ltd | Wholesale & retail | 2017 |
| Bosch Seaways Ltd | Transport & logistics | 2025 |
| Bosphorus Automotive UK Limited | Wholesale & retail | 2019 |
| Boss Barber Donny Limited | Other services | 2024 |
| Bosscher International Ltd | Other services | 2023 |
| Bosworth & Sons' Property Limited | Real estate | 2024 |
| BOT Autocentres Limited | Wholesale & retail | 2017 |
| Botany Business Centre Ltd | Real estate | 2024 |
| Botojo Service Limited | Administrative & support | 2019 |
| Boujie Balloons Limited | Hospitality | 2025 |
| Bounce Around Sheffield Ltd | Arts & recreation | 2015 |
| Bounce Counselling Ltd | Professional & scientific | 2023 |
| Boundaryline Fencing Ltd | Construction | 2026 |
| Bourne Swann Mexborough Limited | Professional & scientific | 2003 |
| Bournecaster Services Limited | Administrative & support | 2024 |
| Boutique Bites Studio Ltd | Extraterritorial | 2023 |
| Bowline Management Ltd | Real estate | 2025 |
| Bowson Industries Limited | Manufacturing | 2013 |
| Box Grill Ciao Ltd | Hospitality | 2026 |
| Box Ridge Development Limited | Construction | 2019 |
| Box Ridge Homes Limited | Construction | 2019 |
| Box to Box Financial Partner Limited | Professional & scientific | 2024 |
| Box Trading Doncaster Limited | Wholesale & retail | 2025 |
| Box Trading UK Ltd | Wholesale & retail | 2020 |
| Boxbarn Limited | Administrative & support | 1995 |
| Boxx Clever (UK) Ltd | Manufacturing | 2025 |
| BOY Racers Limited | Administrative & support | 1987 |
| Boylans (T.V.) Limited | Wholesale & retail | 2001 |