| B.S.C. Footwear Limited | Wholesale & retail | 2017 |
| B.S.E.F.C. Limited | Hospitality | 2007 |
| B9 Agency Limited | Professional & scientific | 2002 |
| Baaj Security Ltd | Administrative & support | 2025 |
| Baanc UK Property Developments Ltd | Real estate | 2026 |
| Bababa Ltd | Wholesale & retail | 2025 |
| Babeyhair Ltd | Wholesale & retail | 2023 |
| Babted Limited | Wholesale & retail | 2013 |
| Baby Care Direct Limited | Wholesale & retail | 2017 |
| Babyfest Ltd | Wholesale & retail | 2023 |
| Bacha Investments Ltd | Real estate | 2024 |
| Backiibasics Ltd | Health & social care | 2025 |
| Backpack Gaming Ltd | Information & communication | 2023 |
| Bacons Fashions Limited | Wholesale & retail | 2009 |
| Bacton Logistics Limited | Transport & logistics | 1991 |
| Bacton Transport Services Holdings Limited | Professional & scientific | 2021 |
| Baddie Cartel Beauty Ltd | Other services | 2021 |
| Badgers Bloodstock Limited | Other services | 2017 |
| Bafway Marine Ltd | Professional & scientific | 2015 |
| Bagda Limited | Extraterritorial | 2000 |
| Bags and Boxes ALL Occasions Ltd | Wholesale & retail | 2022 |
| Bahadur Estates Limited | Real estate | 2024 |
| Bahire Poralekha Ltd | Information & communication | 2026 |
| Bahoxx Ltd | Wholesale & retail | 2025 |
| BAI YA Precision Mould Co., Ltd | Professional & scientific | 2014 |
| Bailey Capital Ventures Ltd | Financial services | 2024 |
| Bailey Sheppard Ltd | Real estate | 2013 |
| Baileys Catering Limited | Manufacturing | 2004 |
| Baines Enterprises Limited | Real estate | 2021 |
| Bajnok Transport Management Ltd | Professional & scientific | 2022 |
| Baker & Nisbet Limited | Construction | 1971 |
| Baker and Springs Ltd | Hospitality | 2011 |
| Bakersguild Ltd | Wholesale & retail | 2025 |
| Bakhat Mart Limited | Wholesale & retail | 2026 |
| Baking Beauty and Beyond Ltd | Other services | 2017 |
| Baking Technology Ltd | Wholesale & retail | 2019 |
| Bala Belle Labs Limited | Wholesale & retail | 2021 |
| Balabe Ltd | Health & social care | 2021 |
| Balaji Benzine Limited | Wholesale & retail | 2012 |
| Baller LAB Ltd | Information & communication | 2025 |
| Balls Pond Place Management Company Limited | Real estate | 2001 |
| Balmforth Property Management Limited | Real estate | 2014 |
| Bamboo Riot Limited | Wholesale & retail | 2026 |
| Bamu Properties Ltd | Real estate | 2026 |
| Bandvolt Ltd | Information & communication | 2026 |
| Banejik Limited | Administrative & support | 2019 |
| Banham's Yard (Hartest) Management Company Limited | Extraterritorial | 2013 |
| Banter Media Group Ltd | Wholesale & retail | 2025 |
| Bantex Limited | Manufacturing | 2003 |
| Bar Bar BB Ltd | Hospitality | 2024 |
| Barankinis Limited | Transport & logistics | 2026 |
| Barbar Food Delivery Ltd | Hospitality | 2025 |
| Barbers-Inc Parlor Ltd | Other services | 2014 |
| Barclay Motors,Limited | Administrative & support | 1947 |
| Barcode Design Limited | Professional & scientific | 2014 |
| Barconwood Limited | Manufacturing | 2005 |
| Bare Automotive Logistics Ltd | Transport & logistics | 2025 |
| Bareadvice Consultancy Limited | Professional & scientific | 2020 |
| Barham Meadows Resident Management Company Limited | Households | 2024 |
| Baribox Ltd | Wholesale & retail | 2025 |
| Bark Like a Big Dog Ltd | Professional & scientific | 2019 |
| Barlikcustoms Ltd | Wholesale & retail | 2026 |
| Barlow the Group Ltd | Information & communication | 2025 |
| Barmans Holdings Limited | Wholesale & retail | 2014 |
| Barmans Limited | Wholesale & retail | 1990 |
| Barmans Property Limited | Real estate | 2022 |
| Barnecons Ltd | Construction | 2025 |
| BARNEY1 Ltd | Hospitality | 2023 |
| Barnley Storage Ltd | Administrative & support | 2017 |
| Barosell Limited | Financial services | 2018 |
| Barq Socials Limited | Professional & scientific | 2026 |
| Barratt & Cooke Holdings Limited | Professional & scientific | 2005 |
| Barratt & Cooke Limited | Financial services | 2005 |
| Barrington Bars Ltd | Hospitality | 2022 |
| Barrow (the Limes) Management Company Limited | Households | 2014 |
| Barton Mills Development Ltd | Construction | 2025 |
| Barton Stallions Limited | Agriculture & fishing | 2021 |
| Basarab Real Estate Ltd | Real estate | 2025 |
| Bascy Ltd | Wholesale & retail | 2025 |
| Base Auto Rentals & Supplies Ltd | Administrative & support | 2022 |
| Base Blowup Ltd | Professional & scientific | 2025 |
| Basezero Limited | Administrative & support | 2026 |
| Basix Brand Ltd | Wholesale & retail | 2023 |
| Bastion Management & Strategy Collective Ltd | Professional & scientific | 2011 |
| Bastion MSC (UK) Ltd | Administrative & support | 2016 |
| Bastion Pictures Limited | Information & communication | 2006 |
| Bateman Brothers Ltd | Real estate | 2024 |
| Baton Corporation Ltd | Wholesale & retail | 2023 |
| Batronics Limited | Manufacturing | 2025 |
| Bay Heating Ltd | Construction | 2021 |
| Bayley Group Ltd | Information & communication | 2026 |
| Bayrock Software Solutions Ltd | Information & communication | 2017 |
| Bays Baes Ltd | Wholesale & retail | 2026 |
| Baytree Equine Limited | Administrative & support | 2014 |
| Baytree Management Limited | Hospitality | 2025 |
| Baytree Property Management Limited | Real estate | 2026 |
| Baytul Hikmah Limited | Information & communication | 2025 |
| BB & Co Properties Ltd | Real estate | 2024 |
| BB & L Limited | Professional & scientific | 2025 |
| BB Airsoft UK Ltd | Wholesale & retail | 2026 |