| Boroughbury Garage Limited | Extraterritorial | 1936 |
| Boroughbury Holdings Limited | Professional & scientific | 1980 |
| Borrowed Insight Ltd | Information & communication | 2016 |
| Borwell Cycles Limited | Wholesale & retail | 2004 |
| BOS Celtic Limited | Financial services | 2026 |
| BOS Panthera Ltd | Real estate | 2025 |
| Boscombe Trading Ltd | Wholesale & retail | 2019 |
| Boskennal Limited | Energy | 2013 |
| Bosporus Holdings Limited | Financial services | 2023 |
| Bosporus Limited | Hospitality | 2015 |
| Boss Cutz Norwich Ltd | Other services | 2026 |
| Boss Leone Ltd | Other services | 2018 |
| Boss Print Limited | Information & communication | 2001 |
| Boss Roofing Contractors Limited | Construction | 2018 |
| Bossyboo Ltd | Professional & scientific | 2024 |
| Bostock Training Limited | Education | 2019 |
| Boston Group of Companies Ltd | Other services | 2018 |
| Boston Management and Law Business School Ltd | Education | 2018 |
| Boswell Court Management Limited | Real estate | 1992 |
| BOT Solutions Ltd | Information & communication | 2022 |
| Botan Enterprises Limited | Real estate | 2017 |
| Botany and Beans Ltd | Wholesale & retail | 2022 |
| Bothwell Gibson Consultancy Ltd | Professional & scientific | 2020 |
| Bottle Holdings Ltd | Extraterritorial | 2022 |
| Boucher Catering Ltd | Hospitality | 2019 |
| Boudica Paving & Landscaping Ltd | Construction | 2023 |
| Boudicca Brewing Company Ltd | Manufacturing | 2015 |
| Bough Digital Ltd | Information & communication | 2010 |
| Bounce Back Castles Ltd | Administrative & support | 2013 |
| Bouncing Beans Nursery Limited | Health & social care | 2015 |
| Bound Jewellery Limited | Wholesale & retail | 2026 |
| Boundary Breakers Ltd | Education | 2020 |
| Boundary FRY Gruop Ltd | Hospitality | 2026 |
| Boundary Norwich Store Ltd | Wholesale & retail | 2024 |
| Boundary Property Management Norfolk Ltd | Real estate | 2023 |
| Boundfield Limited | | 1979 |
| Bounds Consulting Ltd | Agriculture & fishing | 2003 |
| Bountystack Ltd | Arts & recreation | 2026 |
| Bourne Boxing Management Ltd | Arts & recreation | 2024 |
| Bourne Productions Ltd | Information & communication | 2011 |
| Bourne Tractors Limited | Extraterritorial | 2022 |
| Bourne's Fishmongers Limited | Wholesale & retail | 2017 |
| Bournethorpe Limited | Health & social care | 2026 |
| Boutique Fitness Life Limited | Health & social care | 2019 |
| Boutique Living Ltd | Real estate | 2017 |
| BOW Fells Ltd | Real estate | 2026 |
| BOW Industries Ltd | Financial services | 2024 |
| Bower & Jones Housing and Development Ltd | Real estate | 2017 |
| Bowhill & Elliott (East Anglia) Limited | Manufacturing | 1944 |
| Bowhill & Elliott Limited | Manufacturing | 2022 |
| Bowlers Green Estate Management Ltd | Real estate | 2021 |
| Bowles Estates Ltd | Real estate | 2022 |
| Bowling House Ltd | Hospitality | 2016 |
| Bowmonk Limited | Manufacturing | 1966 |
| Bowmy Limited | Real estate | 1977 |
| Bowthorpe Community Trust | Health & social care | 2012 |
| Bowthorpe Manufacturing Limited | Manufacturing | 2024 |
| BOX30 Limited | Arts & recreation | 2018 |
| Boxe Brighton Limited | Arts & recreation | 2024 |
| Boxe Clacton Limited | Arts & recreation | 2025 |
| Boxe Harlow Limited | Arts & recreation | 2025 |
| Boxe Hertford Ltd | Arts & recreation | 2024 |
| Boxe Holdings Ltd | Financial services | 2024 |
| Boxe Romford Limited | Arts & recreation | 2021 |
| Boxe Soho Ltd | Arts & recreation | 2024 |
| Boxing Hare Press & Publishing Ltd | Information & communication | 2019 |
| Boxing Logistics Ltd | Transport & logistics | 2020 |
| Boxkitchen Coffee Ltd | Hospitality | 2021 |
| Boxqo Ltd | Wholesale & retail | 2020 |
| BP Decorators Limited | Construction | 2025 |
| BP Motors Ltd | Wholesale & retail | 2026 |
| BP Solihull Limited | Hospitality | 2023 |
| BP Staffordshire Limited | Hospitality | 2019 |
| BP Visions Ltd | Construction | 2025 |
| BPG Sales Ltd | Wholesale & retail | 2012 |
| BPG SPV1 Ltd | Real estate | 2026 |
| BPGJV1 Limited | Real estate | 2020 |
| Bplanet Ltd | Professional & scientific | 2021 |
| BPR Architects Ltd | Professional & scientific | 1985 |
| BPS 2015 Ltd | Financial services | 2015 |
| BPW Education LLP | | 2024 |
| Brackets Digital Limited | Information & communication | 2015 |
| Bracon ASH Development Land Limited | Construction | 2022 |
| Bracon ASH Developments Limited | Construction | 2016 |
| Bracondale Court Management Limited | Households | 1997 |
| Bracondale Court Residents Association Limited | Households | 2017 |
| Bradbury & Bradbury Limited | Professional & scientific | 2022 |
| Bradfield AC and Refrigeration Ltd | Manufacturing | 2025 |
| Bradfield Bespoke Ltd | Manufacturing | 2011 |
| Bradfield Plastering Company Ltd | Construction | 2023 |
| Bradford Property Investments Limited | Real estate | 2024 |
| Bradford Wealth Investments Limited | Financial services | 2025 |
| Bradley Hatch Limited | Wholesale & retail | 2000 |
| Bradley Road Energy Centre Limited | Energy | 2021 |
| Bradmore Spices Limited | Hospitality | 2023 |
| Bragg of Briston Limited | Wholesale & retail | 2002 |
| Brahma Properties Limited | Real estate | 2014 |
| Brain Immune Media Ltd | Information & communication | 2011 |
| Braini Ltd | Information & communication | 2025 |
| Brainstorm Strategy Ltd | Professional & scientific | 2017 |