| Black Velvet Bar Ltd | Hospitality | 2021 |
| Black Wolf Logistics Ltd | Transport & logistics | 2025 |
| Blackburn Cafe Ltd | Hospitality | 2019 |
| Blackcat Plant & Groundworks Ltd | Other services | 2017 |
| Blacker Hill Estate Limited | Real estate | 2026 |
| Blackergreen Investments Limited | Real estate | 2020 |
| Blackfords Barnsley Limited | Wholesale & retail | 2016 |
| Blackout 13 Limited | Wholesale & retail | 2024 |
| Blacksell Property Ltd | Real estate | 2021 |
| Blackstone Developments (Ardsley) Ltd | Construction | 2023 |
| Blackstone Developments Ltd | Construction | 2003 |
| Blackthorn Repair Management Ltd | Administrative & support | 2020 |
| Blackwatch Consulting Ltd | Professional & scientific | 2025 |
| Blackzu Ltd | Transport & logistics | 2025 |
| Bladancy Limited | Wholesale & retail | 2025 |
| Blaeb Holdings Limited | Financial services | 2025 |
| Blaine Robin Ltd | Real estate | 2025 |
| Blake Construction and Maintenance Limited | Construction | 2019 |
| Blakeridge Ground Rents Limited | Real estate | 2017 |
| Blakeridge Properties Limited | Real estate | 2025 |
| Bland Scaffolding Limited | Construction | 1985 |
| Bland Scaffolding Services Ltd | Construction | 2024 |
| Blank Media Services Limited | Wholesale & retail | 2012 |
| Blasc Properties Limited | Real estate | 2022 |
| Blazebrite Ltd | Construction | 2005 |
| BLB89 Ltd | Transport & logistics | 2016 |
| Bleakley Homes Limited | Real estate | 2025 |
| Bleeding Beauty Boutique Ltd | Manufacturing | 2022 |
| Blend Therapy Ltd | Health & social care | 2025 |
| Blended WAX Melts & More Ltd | Manufacturing | 2025 |
| BLG Collective Ltd | Information & communication | 2026 |
| Blkk Renovations Ltd | Construction | 2025 |
| Blkrck Ltd | Information & communication | 2022 |
| BLM Rentals Ltd | Construction | 2022 |
| Block Influence Ltd | Information & communication | 2018 |
| Blockstar Cleaning Solutions Ltd. | Administrative & support | 2021 |
| Bloodforged Games Ltd | Wholesale & retail | 2022 |
| Bloom Aesthetics Training Limited | Other services | 2020 |
| Bloom Ecommerce Ltd | Wholesale & retail | 2025 |
| Bloomfield House Management Limited | Households | 2005 |
| Blooming Realistic Ltd | Wholesale & retail | 2025 |
| Bloomlift Limited | Wholesale & retail | 2025 |
| Bloomsburys Carpets Ltd | Construction | 2025 |
| Blow Investments Limited | Construction | 2020 |
| Blu's Towngate TAP Limited | Hospitality | 2025 |
| Blue Beret Charitable Trust | Other services | 2021 |
| Blue Blue Properties Ltd | Real estate | 2021 |
| Blue Check Consulting Limited | Real estate | 2015 |
| Blue Portal Voice & Data Ltd | Information & communication | 2016 |
| Blue RAY Healings Ltd | Health & social care | 2023 |
| Blue Skies Ahead Advisory Limited | Professional & scientific | 2023 |
| Blue Street Services Ltd | Professional & scientific | 2006 |
| Bluebell Retail Ltd | Wholesale & retail | 2013 |
| Blueberry Ssas Holdings Limited | Real estate | 2023 |
| Bluecharge Direct Ltd | Information & communication | 2013 |
| Blueeolives Ltd | Wholesale & retail | 2025 |
| Bluemet Labels Ltd | Manufacturing | 2017 |
| Bluemet Ltd | Manufacturing | 2023 |
| Bluemet Technology Ltd | Manufacturing | 2023 |
| Blueport Health Limited | Other services | 2026 |
| Blueprint Business Coach Ltd | Professional & scientific | 2025 |
| Blueridge Financial Planning Limited | Financial services | 2026 |
| Bluesky Management Services Limited | Professional & scientific | 2021 |
| Bluezone Healthcare Limited | Health & social care | 2023 |
| BM Doors Limited | Manufacturing | 2024 |
| Bmbc Services Limited | Administrative & support | 2013 |
| BMK Tiling Limited | Construction | 2016 |
| Bmnc Limited | Wholesale & retail | 2025 |
| BMO Gym and Fitness Limited | Arts & recreation | 2025 |
| BMV Training Ltd | Education | 2017 |
| BN Civil and Tarmac Solutions Ltd | Construction | 2025 |
| BNH Associates Limited | Professional & scientific | 2002 |
| Bnsp Inman Limited | Transport & logistics | 2019 |
| BO Homes (Yorkshire) Ltd | Construction | 2020 |
| BOB Transport Ltd | Transport & logistics | 2025 |
| Bob's Business Limited | Education | 2007 |
| Boba Tea Bar Ltd | Wholesale & retail | 2024 |
| Bobs Taxis Limited | Extraterritorial | 2012 |
| Bobster Ltd | Professional & scientific | 2022 |
| Boco Interiors Ltd | Extraterritorial | 2021 |
| Boco Ltd | Construction | 2021 |
| Body & Spirit Clinic Ltd | Education | 2025 |
| Body Revive Limited | Other services | 2019 |
| Bodyshop Mafia Ltd | Wholesale & retail | 2021 |
| Bodyvie Limited | Health & social care | 1999 |
| Bofen Athersley Ltd | Construction | 2025 |
| Bofen Construction Ltd | Construction | 2026 |
| Bofen Homes Limited | Construction | 2024 |
| Bofen Rental Ltd | Real estate | 2024 |
| Bofen Royston Ltd | Construction | 2025 |
| Bogdan Andries Ltd | Transport & logistics | 2019 |
| Bogdan Ghencea Ltd | Health & social care | 2017 |
| Bombay Two Ltd | Hospitality | 2020 |
| Bondell Electrical Limited | Construction | 2015 |
| Bondterm Limited | Real estate | 1987 |
| Bonne Construction Ltd | Construction | 2026 |
| Bonnell Windows Limited | Construction | 2023 |
| Bonney Enterprises Limited | Real estate | 2025 |
| Book My Skip Ltd | Water & waste | 2025 |
| Booker Commercial Limited | Real estate | 1968 |