| B W Birmingham Ltd | Hospitality | 2013 |
| B-A-T London Limited | Transport & logistics | 2020 |
| B2B Growth Consulting Ltd | Professional & scientific | 2014 |
| Babar Management Limited | Real estate | 2015 |
| Babel Green Ltd | Wholesale & retail | 2019 |
| Baburaj Ltd | Health & social care | 2012 |
| Backs to Basics Osteopathy Ltd | Health & social care | 2006 |
| Baijul Shah Family Office Limited | Professional & scientific | 2016 |
| Baker Housing Ltd | Hospitality | 2018 |
| Bakul Design Limited | Administrative & support | 2015 |
| Balaji Property & Development Limited | Construction | 2022 |
| Balanced Path Ltd | Professional & scientific | 2026 |
| Ballyfox Limited | Real estate | 2024 |
| Ballyrose Ltd | Real estate | 2025 |
| Bamunu Ltd | Financial services | 2021 |
| Banerjeeworld Services Ltd | Professional & scientific | 2024 |
| Banoi Cleaning Ltd | Administrative & support | 2017 |
| Banoi Services Ltd | Households | 2016 |
| Banwait Global Investments Ltd | Real estate | 2008 |
| Barnes & Hicks Limited | Other services | 2003 |
| Barry Maniloft Ltd | Wholesale & retail | 2013 |
| Bash Projects Ltd | Real estate | 2022 |
| Basingstoke Residential Limited | Construction | 2021 |
| Bassline Logistics Limited | Transport & logistics | 2026 |
| Batchworth Wealth Management Limited | Extraterritorial | 2012 |
| Batra Property Investments Ltd. | Real estate | 2020 |
| BB Seamless Real Estate Solutions Ltd | Real estate | 2022 |
| Bbac Construction Ltd | Construction | 2021 |
| BBB Cars AL Ltd | Wholesale & retail | 2026 |
| Bbbr Trading Limited | Financial services | 2024 |
| Bbkroots Limited | Information & communication | 2025 |
| BBR Construction Limited | Construction | 2018 |
| BCB Plumbing Ltd | Construction | 2018 |
| BCK Solutions Limited | Professional & scientific | 2014 |
| BCL Cars Limited | Wholesale & retail | 2016 |
| BD 1 Limited | Real estate | 2026 |
| BD BAS Holdings Limited | Financial services | 2026 |
| BD Mortgage Advice Ltd | Financial services | 2025 |
| BDH Distribution Limited | Information & communication | 2012 |
| BDP (UK) Milton Keynes Limited | Real estate | 2006 |
| BE Free Love Yoga Limited | Arts & recreation | 2016 |
| Beans Housing Ltd | Hospitality | 2017 |
| Beast Scaffold Supplies Ltd | Construction | 2025 |
| Beauty by Kinjal Ltd | Other services | 2019 |
| Beautybitz Ltd | Other services | 2025 |
| BEC Bound 2 Flourish Ltd | Health & social care | 2023 |
| Bedford Assets Ltd | Real estate | 2021 |
| Beeboo Worldwide Ltd | Manufacturing | 2024 |
| Beef Brazil Ltd | Wholesale & retail | 2026 |
| Beeline Cars UK Ltd | Administrative & support | 2024 |
| Begbroke Leisure Limited | Financial services | 2021 |
| Bella BEE Limited | Information & communication | 2012 |
| Bellasis Road Limited | Real estate | 2017 |
| Bellford Developments Limited | Construction | 2000 |
| Ben's Brothers Limited | Construction | 2016 |
| Benaisha Mehta Consultancy Limited | Professional & scientific | 2025 |
| Benefacitis Limited | Administrative & support | 2020 |
| Berkeley Resource Group Limited | Wholesale & retail | 2024 |
| Bespoke Prime Property Solutions Limited | Real estate | 2020 |
| Bespoke Procurement Management Limited | Wholesale & retail | 2025 |
| Bestbuy Worldwise Ltd | Wholesale & retail | 2026 |
| Bethany Properties Limited | Real estate | 2021 |
| Bethlehem Baubles Ltd | Wholesale & retail | 2020 |
| Beverley Barbican Ltd | Health & social care | 2017 |
| Beyond Basic Marketing Ltd | Professional & scientific | 2024 |
| BFS Security Ltd | Administrative & support | 2026 |
| Bhachu Property & Development Ltd | Construction | 2017 |
| Bhalzi Consultancy Limited | Financial services | 2017 |
| Big ANT UK Limited | Extraterritorial | 2014 |
| Billian I.T. Solutions Limited | Information & communication | 1995 |
| Biloz Ltd | Real estate | 2007 |
| Binit Shah & Co. Limited | Wholesale & retail | 2016 |
| Biogenes Technologies Limited | Professional & scientific | 2025 |
| Birah Holdings Limited | Other services | 2026 |
| Birch Tree Ventures Ltd | Information & communication | 2019 |
| Birken Court Limited | Households | 2005 |
| Biro Utilities Ltd | Construction | 2026 |
| Biteline Ltd | Wholesale & retail | 2025 |
| Biteline Trading Limited | Wholesale & retail | 2025 |
| BL Garden (UK) Limited | Administrative & support | 2023 |
| Black Bear Assets Limited | Financial services | 2023 |
| Black Wolf Pictures Ltd | Information & communication | 2019 |
| Blackbox Consulting (UK) Limited | Administrative & support | 2022 |
| Blackmansion Ltd | Construction | 2025 |
| Blackridge Planning Insight Ltd | Professional & scientific | 2026 |
| Blaircrest Limited | Households | 1981 |
| Blanesworth Ltd | Real estate | 2020 |
| Blind Technique Limited | Manufacturing | 2004 |
| Blissful Group Ltd | Wholesale & retail | 2023 |
| Blits Traders Limited | Wholesale & retail | 2025 |
| Bloc Carbon Limited | Administrative & support | 2020 |
| BLOCK212 Ltd | Information & communication | 2024 |
| Blooming Tastebuds Limited | Education | 2024 |
| Blooming Tulips Montessori Ltd | Education | 2023 |
| Blossom Farm Montessori Limited | Education | 2017 |
| Blossom Tree Montessori Limited | Education | 2017 |
| Blue Agile Ltd | Administrative & support | 2025 |
| Blue Bell Foods Limited | Hospitality | 2011 |
| Blue Data Technologies Ltd | Information & communication | 2016 |
| Blue Elephant Films Limited | Professional & scientific | 2008 |