| BLR Fabrications Limited | Manufacturing | 2024 |
| BLS Shop Ltd | Hospitality | 2023 |
| BLU Project Systems Ltd | Professional & scientific | 2023 |
| Blu-Pearl Limited | Real estate | 2024 |
| Blue ARC Welding Limited | Construction | 2012 |
| Blue Box Services Limited | Administrative & support | 1997 |
| Blue Gate Marketing Limited | Professional & scientific | 2024 |
| Blue Ice 75 Ltd | Wholesale & retail | 2023 |
| Blue Marble Trending Ltd | Wholesale & retail | 2018 |
| Blue Ocean Grimsby Limited | Hospitality | 2012 |
| Blue Pier Ltd | Professional & scientific | 2026 |
| Blue Social Limited | Professional & scientific | 2016 |
| Blue Star Fibres Company Limited | Manufacturing | 2006 |
| Blue Tower Group Ltd | Real estate | 2023 |
| Blue Tower Services Ltd. | Real estate | 2019 |
| Bluecrest Foods Limited | Wholesale & retail | 1980 |
| Bluegem Consultants Limited | Professional & scientific | 1995 |
| Blueprint Automation UK Limited | Administrative & support | 1990 |
| Bluesky (UK) Limited | Administrative & support | 2011 |
| Blundell Project Management Limited | Professional & scientific | 2012 |
| Blys Lingerie Ltd | Wholesale & retail | 2026 |
| Blyths Inspection Ltd | Other services | 2025 |
| BM Cooling Limited | Construction | 2024 |
| BM Testing (Lincs) Limited | Transport & logistics | 2018 |
| Bmac Distribution Ltd | Transport & logistics | 2019 |
| BMC81 Construct Ltd | Construction | 2025 |
| Bmcg (A1) Limited | | 2002 |
| BML Heating & Plumbing Services Limited | Construction | 2019 |
| Boaca Evelina Limited | Transport & logistics | 2026 |
| Bobbys Auto Ltd | Professional & scientific | 2026 |
| Boclair Site Services Limited | Construction | 2026 |
| Body Contour Clinic Ltd | Other services | 2025 |
| BOI Electrical Services Ltd | Construction | 2024 |
| Boiler-Tech GAS Services Limited | Construction | 2019 |
| Boiler-Tech Installations Limited | Construction | 2020 |
| Bold Healthcare Limited | Health & social care | 2019 |
| Boms & Prie Ltd | Professional & scientific | 2025 |
| Bondline Limited | Manufacturing | 2012 |
| Bonnie and Clyde's Grimsby Ltd | Other services | 2026 |
| Bonxai Skate Co Ltd | Wholesale & retail | 2020 |
| Booch Services Ltd | Arts & recreation | 2023 |
| Booloo Limited | Real estate | 2023 |
| Booth Engineering Ltd | Professional & scientific | 2021 |
| Boothecom Ltd | Wholesale & retail | 2021 |
| BOP Animations Ltd | Arts & recreation | 2019 |
| Bordas Holdings Ltd | Financial services | 2024 |
| Boreas Contracts Ltd | Construction | 2022 |
| Boston Mayflower Finance PLC | Hospitality | 2014 |
| Bottega Magica Ltd | Wholesale & retail | 2025 |
| Bouch Tyre's Ltd | Wholesale & retail | 2025 |
| Boughton Garage Ltd | Wholesale & retail | 2019 |
| Bounce Back AP Ltd. | Education | 2023 |
| Bouncy Bunnies Hampshire Ltd | Other services | 2017 |
| Bower Site Services Limited | Construction | 2020 |
| Bowers Birch Limited | Real estate | 2025 |
| Boyce Barbers Limited | Other services | 2010 |
| BPM Management Ltd | Construction | 2016 |
| BQA Monitoring Ltd | Information & communication | 2013 |
| Brabben Limited | Construction | 2022 |
| Brad Francis Thinking Safety Limited | Construction | 2017 |
| Bradbury Gardens Management Company Limited | Households | 2023 |
| Bradley Barbers Ltd | Other services | 2025 |
| Bradley Brothers Distribution Limited | Wholesale & retail | 2024 |
| Bradley Grimsby Limited | Hospitality | 2025 |
| Bradley Lakes Ltd | Hospitality | 2021 |
| Bradley Roofing Ltd | Construction | 2018 |
| Bradshaw Support Limited | Health & social care | 2011 |
| Bramble Products Ltd | Manufacturing | 2016 |
| Brambles Beauty & Tanning Studio Ltd | Other services | 2020 |
| Bramwell's Plumbing and Heating Limited | Construction | 2025 |
| Brand Venture International Limited | Wholesale & retail | 2023 |
| Brandable Creative Limited | Professional & scientific | 2017 |
| Brandon Properties Group Ltd | Real estate | 2021 |
| Brauer Transport Ltd | Transport & logistics | 2024 |
| Bravo Charlie Alpha Limited | Construction | 2015 |
| Braydean Properties Limited | Real estate | 1999 |
| Breadbuns Ltd | Financial services | 2016 |
| Breethe Financial Support Services Ltd | Administrative & support | 2011 |
| Bremner Security Systems Limited | Administrative & support | 2025 |
| Brentwood Aquatics (Wholesale) Ltd | Wholesale & retail | 2016 |
| Brereton Motor Co Ltd | Wholesale & retail | 2003 |
| Breta Holdings Ltd | Real estate | 2026 |
| Bretts Trading Limited | Other services | 2016 |
| Brews of the World Limited | Wholesale & retail | 2017 |
| Brian Colcombe Ltd | Professional & scientific | 2012 |
| Brian Mager Limited | Real estate | 1957 |
| Brian Tynan Limited | Professional & scientific | 2006 |
| Bridal House of Lincolnshire Ltd | Wholesale & retail | 2022 |
| Bridge Dental and Implant Clinic Limited | Health & social care | 2010 |
| Bridge Holdings (Derby) Limited | Health & social care | 2025 |
| Bridge Mcfarland (Bmcf) Limited | Professional & scientific | 2005 |
| Bridge Street Management (Brigg) Limited | Households | 2020 |
| Bridgeland Group Limited | Financial services | 2022 |
| Bridgeland Properties Limited | Real estate | 2020 |
| Briggs & Co Developments Limited | Construction | 2021 |
| Brighowgate Fast Food Ltd | Hospitality | 2026 |
| Bright East Technologies Limited | Information & communication | 2026 |
| Bright Matter Resourcing Limited | Administrative & support | 2014 |
| Brighter Construction 1 Limited | Construction | 2024 |
| Brighter Construction Limited | Construction | 2020 |