| Bart Express Limited | Transport & logistics | 2016 |
| Basenote Solutions Ltd | Manufacturing | 2025 |
| Bashar Moghaddam Limited | Health & social care | 2017 |
| Basildon Metals Limited | Administrative & support | 2013 |
| Basildon Scrap Co Limited | Administrative & support | 2013 |
| Bassi Vehicle Services Ltd | Wholesale & retail | 2025 |
| Bastion Group UK Ltd | Construction | 2020 |
| Batchelor Street Takeaway Limited | Hospitality | 2025 |
| Batching & Blending Systems Limited | Manufacturing | 1996 |
| Batching Solutions Ltd | Professional & scientific | 2013 |
| Bathbuild Ltd | Construction | 2021 |
| Bathglaze and Co. Limited | Construction | 2017 |
| Bathglaze Limited | Construction | 2012 |
| Bathgrip Limited | Construction | 2017 |
| Battochus Prime Limited | Transport & logistics | 2023 |
| Bauhinia Developments Limited | Wholesale & retail | 2022 |
| Baykem Ltd | Administrative & support | 2015 |
| BB (CMR) Ltd | Other services | 2018 |
| BB Flooring (Surrey) Ltd | Construction | 2014 |
| BB Groundworks & Civils Ltd | Construction | 2022 |
| BB Pronet Ltd | Construction | 2013 |
| BBS Builds Ltd | Construction | 2023 |
| BC Property Services Limited | Real estate | 2020 |
| BCC- Bridge Construction Consulting Limited | Construction | 2024 |
| Beach Real Estate Limited | Construction | 2026 |
| Beacon House Management (Chatham) Limited | Extraterritorial | 1991 |
| Beacon Partners Group Ltd | Hospitality | 2025 |
| Bearman HR Consultancy Ltd | Administrative & support | 2023 |
| Bearsted Blitzers Limited | Administrative & support | 2023 |
| Beatrix Beauty Limited | Wholesale & retail | 2018 |
| Beau Elle Ltd | Other services | 2012 |
| Beautifully Balanced Ltd | Professional & scientific | 2026 |
| Beaux Creatives Limited | Wholesale & retail | 2023 |
| Bebb Property Limited | Real estate | 2022 |
| Becden Ltd | Administrative & support | 2011 |
| Beck Utilities LLP | | 2011 |
| Bee-Equipment Ltd | Agriculture & fishing | 2002 |
| Beejot Property Ltd | Real estate | 2022 |
| Beertec Ltd | Construction | 2018 |
| Bees Knees Plumbing and Heating Ltd | Construction | 2023 |
| Beever Enhancements Limited | Wholesale & retail | 2012 |
| Begonia Ltd | Health & social care | 2013 |
| Begood Care Limited | Professional & scientific | 2022 |
| Begood Properties Limited | Construction | 2021 |
| BEH Management Company Limited | Real estate | 2025 |
| Behind the Force Ltd. | Administrative & support | 2013 |
| Beholdco Limited | Financial services | 2025 |
| Belake Research Ltd. | Professional & scientific | 2013 |
| Belgravia Hardwood Windows & Doors Ltd | Other services | 2020 |
| Bell Roofing Merchants Ltd | Transport & logistics | 2007 |
| Bella EVE Limited | Other services | 2012 |
| Bella Rose Boutique Ltd | Wholesale & retail | 2024 |
| Bellaco Estates Ltd | Real estate | 2023 |
| Bellaco Properties Ltd | Real estate | 2024 |
| Bellamy Consultants Ltd | Professional & scientific | 2018 |
| Bellamy Price Jeffery and Co Ltd | Real estate | 2020 |
| Bellastouch Ltd | Professional & scientific | 2017 |
| Bellava Limited | Wholesale & retail | 2008 |
| Bella’S Cleaning Services Ltd | Administrative & support | 2024 |
| Bellmill Consulting Limited | Real estate | 2020 |
| Bellogun Commercial Group Ltd | Construction | 2026 |
| Bells and Whistles Event Stylist Ltd | Health & social care | 2021 |
| Belron Services Ltd | Professional & scientific | 2026 |
| Belvedere Lingua Ltd | Education | 2024 |
| BEN Davis Access Solutions Ltd | Construction | 2025 |
| BEN Warne Resin Flooring Specialist Ltd | Construction | 2026 |
| Ben's Roofing Limited | Construction | 2019 |
| Benchmark Electrical Services Limited | Construction | 2020 |
| Benedictus Solutions Limited | Information & communication | 2016 |
| Benfleet Scrap Co Limited | Water & waste | 1995 |
| Benfleet Waste Recycling Limited | Extraterritorial | 2015 |
| Bennetts Farm (Stoke) Limited | Extraterritorial | 1968 |
| Berengravers Ltd | Other services | 2006 |
| Bernaire Ltd | Hospitality | 2023 |
| Bertie and Brummell Limited | Wholesale & retail | 2015 |
| Bertotools Limited | Agriculture & fishing | 2008 |
| Bertson Holdings Ltd | Real estate | 2026 |
| Bery Lettings Limited | Real estate | 2016 |
| Beslic Limited | Financial services | 2022 |
| Bespoke Brick Properties Ltd | Real estate | 2021 |
| Bespoke Construction Kent Ltd | Construction | 2023 |
| Bespoke Counselling and Psychotherapy Limited | Other services | 2015 |
| Bespoke Garden Lodges Ltd | Construction | 2021 |
| Bespoke Outdoor Solutions Limited | Construction | 2016 |
| Best 1 Heating & GAS Ltd | Construction | 2017 |
| Best Nails Limited | Other services | 2023 |
| Best Nest Homes Ltd | Real estate | 2026 |
| Best Service Cleaner Ltd | Administrative & support | 2025 |
| BET Kitchens Ltd | Manufacturing | 2021 |
| Beta Property Investments Ltd | Real estate | 2017 |
| Bethel Strides Logistics Limited | Transport & logistics | 2025 |
| Betterme Direction Ltd | Information & communication | 2024 |
| Betterview Properties Limited | Manufacturing | 2023 |
| Beverley Beer Limited | Other services | 2011 |
| Beverley Smiths UK Limited | Wholesale & retail | 2009 |
| Bew-Dogs Ltd | Wholesale & retail | 2022 |
| Bexley Financial Solutions Ltd | Financial services | 2008 |
| Beyond 1945 Ltd | Professional & scientific | 2025 |
| Beyond Racing Team Limited | Arts & recreation | 2018 |
| Beyond Schools Trust | Education | 2010 |