| BMC Housing C.I.C. | Hospitality | 2024 |
| BMC Interiors Ltd | Professional & scientific | 2018 |
| BMC Plastering Services Ltd | Construction | 2019 |
| BMC Venetian Plastering Limited | Construction | 2021 |
| Bmet Limited | Real estate | 2000 |
| BMK Contracting Engineering Limited | Extraterritorial | 2018 |
| BML Engineering Ltd | Manufacturing | 2023 |
| BMS Machining (Coventry) Ltd | Manufacturing | 2026 |
| BMS Machining Group Ltd | Manufacturing | 2026 |
| BN Services (North) Ltd | Health & social care | 2019 |
| BN23 Investments Ltd | Financial services | 2022 |
| BNF Care Ltd | Public administration | 2025 |
| BNH Systems Ltd | Wholesale & retail | 2018 |
| BNI Northants Networking Limited | Other services | 2021 |
| BNM Consulting Limited | Extraterritorial | 2015 |
| BNN Healthcare Ltd | Health & social care | 2013 |
| BNN Technology PLC | Information & communication | 2008 |
| BNO Transport Ltd | Transport & logistics | 2024 |
| BNZ Interiors Limited | Construction | 2017 |
| Bo&Co (Northampton) Ltd | Extraterritorial | 2019 |
| BO55 Cars Ltd | Transport & logistics | 2025 |
| Boarders Boards Limited | Wholesale & retail | 2008 |
| Boardman Aviation Ltd | Transport & logistics | 2025 |
| Boat Street Events Limited | Other services | 2023 |
| BOB Rotrans Ltd | Other services | 2019 |
| Bob's Garage Northampton Limited | Wholesale & retail | 2026 |
| Bobby Rabbit Limited | Wholesale & retail | 2015 |
| Bobby's Playhouse Limited | Education | 2001 |
| Bobcar Services Limited | Transport & logistics | 2006 |
| Bobcat Distribution Limited | Other services | 2017 |
| Bobcat Mortgages Ltd | Financial services | 2024 |
| Bobo Speed Ltd | Transport & logistics | 2026 |
| Boboc Transport Limited | Transport & logistics | 2026 |
| Bobos Inc Ltd | Agriculture & fishing | 2015 |
| Bobstef Trans Ltd | Transport & logistics | 2019 |
| Boby & Darius Ltd | Hospitality | 2018 |
| Boca JAY Salokin Ltd | Administrative & support | 2017 |
| Bocin Logistics Ltd | Transport & logistics | 2024 |
| Boden & Ward London Limited | Construction | 2004 |
| Boden and Ward Stonemasons Limited | Construction | 1998 |
| Bodiclinic Ltd | Health & social care | 2015 |
| Bodily Heating & Plumbing Ltd | Construction | 2024 |
| Bodmec Limited | Administrative & support | 2018 |
| Bodrum Kebab Pizza Ltd | Hospitality | 2024 |
| Body Expert Ltd | Wholesale & retail | 2015 |
| Bodyform Collective Ltd | Wholesale & retail | 2026 |
| Bodypower Properties Limited | Real estate | 2014 |
| Bodypower Sports Holdings Limited | Professional & scientific | 2014 |
| Bodypower Sports Ltd | Wholesale & retail | 1998 |
| Boehmward Limited | Real estate | 2017 |
| Boffo Ltd | Construction | 2017 |
| Boffoworks Limited | Information & communication | 2015 |
| Bofty&Co Ltd. | Health & social care | 2019 |
| Bofu Trans Ltd | Transport & logistics | 2018 |
| Bogdan Carpentry Ltd | Construction | 2021 |
| Bogdan Grecu Limited | Administrative & support | 2018 |
| Bogdan Industry Ltd | Transport & logistics | 2024 |
| Bogdan Interiors Ltd | Construction | 2020 |
| Bogdan Speed Trans Ltd | Transport & logistics | 2026 |
| Bogdan Track Ltd | Mining & quarrying | 2014 |
| Bogdan Trans Group Ltd. | Transport & logistics | 2019 |
| Bogdanel Interiors Limited | Extraterritorial | 2023 |
| Bogdani Construction Ltd | Construction | 2021 |
| Bogdy Trans Ltd | Transport & logistics | 2015 |
| Bogsab Ltd | Transport & logistics | 2018 |
| Bogumil Limited | Transport & logistics | 2007 |
| Bohdan Property Management Ltd | Real estate | 2024 |
| Bohemia Tax Ltd | Extraterritorial | 2011 |
| Bohemian Finds Ltd | Wholesale & retail | 2014 |
| Bohemian Mews Limited | Construction | 2026 |
| Bohun Ltd | Transport & logistics | 2010 |
| Bohye MMA Club | Other services | 2024 |
| Boilerhouse Creative Communications Limited | Professional & scientific | 2014 |
| Bold and Beyond Ltd | Wholesale & retail | 2025 |
| Bold Innovation Group Ltd | Professional & scientific | 2024 |
| Bolfis Limited | Transport & logistics | 2021 |
| Bolos Trans Limited | Transport & logistics | 2017 |
| Bolst Business Consultancy Limited | Professional & scientific | 2012 |
| Bolt Breakthrough Ltd | Administrative & support | 2025 |
| Boltim Decorators Limited | Construction | 2023 |
| BOM Galiano Ltd | Information & communication | 2025 |
| Boma Group Ltd | Professional & scientific | 2025 |
| Bomain Ltd | Information & communication | 2025 |
| Bomati Ltd | Transport & logistics | 2014 |
| Bombay Palace Restaurant (Northants) Ltd | Hospitality | 2007 |
| Bomby Buy Limited | Health & social care | 2015 |
| BON Holdings Ltd | Real estate | 2025 |
| BON Partners Holdings Limited | Real estate | 2024 |
| BON Partners LLP | | 2010 |
| Bonart Limited | Extraterritorial | 1961 |
| Bond & Basket CIC | Hospitality | 2026 |
| Bond Capital Finance Ltd | Extraterritorial | 2015 |
| Bond Capital Limited | Financial services | 2002 |
| Bond Capital Loans Limited | Financial services | 1994 |
| Bond Land Consultants Limited | Real estate | 2018 |
| Bonds Property Holdings Ltd | Financial services | 2026 |
| Bonds Residential Holdings Ltd | Real estate | 2026 |
| Bond’S Property Management Limited | Households | 2024 |
| Bonham Construction Ltd | Administrative & support | 2022 |
| Bonnie Trans Ltd | Transport & logistics | 2020 |