| Beyond the Scene Limited | Professional & scientific | 2015 |
| Beyond the Shutter Limited | Wholesale & retail | 2020 |
| BFG Clearance Limited | Water & waste | 2024 |
| BFG Svcs Limited | Professional & scientific | 2025 |
| Bgjm Limited | Extraterritorial | 2014 |
| BGW Building Services Ltd | Administrative & support | 2019 |
| BH Guitar Entertainment Limited | Information & communication | 2025 |
| Bhavansh Limited | Hospitality | 2024 |
| BHB Partners Limited | Administrative & support | 2012 |
| Bhcw Ltd | Other services | 2018 |
| BHG Flooring Ltd | Construction | 2017 |
| BHZ Media Limited | Manufacturing | 2014 |
| BHZ Obtain Limited | Manufacturing | 2020 |
| Bickleys Court Management Limited | Households | 2013 |
| Bidpoint Solutions Limited | Professional & scientific | 2025 |
| BIF Limited | Wholesale & retail | 2016 |
| Big Bird Trading Limited | Manufacturing | 2016 |
| Big Picture AV Ltd | Professional & scientific | 2011 |
| Big Three Holdings Limited | Real estate | 2025 |
| Big Three Strategic Ltd | Professional & scientific | 2025 |
| Big Wedge Ltd | Information & communication | 2023 |
| BIGLIGHT1 Ltd | Hospitality | 2023 |
| Bika Cuisine Ltd | Hospitality | 2025 |
| Bill Kent Building & Roofing Ltd | Construction | 2024 |
| Billaway Developments Limited | Construction | 1989 |
| Billericay Dental Studio Limited | Health & social care | 2014 |
| Billy and Beyond CIC | Professional & scientific | 2021 |
| Billy Wingrove Properties Limited | Real estate | 2020 |
| Billy's on the Beach Limited | Hospitality | 2013 |
| Binocular Limited | Professional & scientific | 2006 |
| Bioceres Group Limited | Financial services | 2021 |
| Biometric Technologies Ltd | Administrative & support | 2010 |
| Birch Property Services Ltd | Other services | 2007 |
| Bird & Blend Tea Ltd. | Manufacturing | 2013 |
| Bird Rock Ltd | Hospitality | 2024 |
| Bishop Building & Carpentry Limited | Construction | 2021 |
| Bishops Court (Worthing) Management Limited | Households | 1967 |
| Bishops Homecare Ltd | Construction | 2017 |
| Bishops Properties Ltd | Real estate | 2019 |
| Bisonica Technologies Ltd | Manufacturing | 2026 |
| Bites Cafe Limited | Hospitality | 2017 |
| Bitwize Limited | Information & communication | 2024 |
| Biz-Works UK Ltd | Financial services | 2005 |
| Bizzwizard Ltd | Education | 2021 |
| BJ Designs Stage Engineering Specialists Ltd | Professional & scientific | 2005 |
| Bjes Construction Ltd | Construction | 2019 |
| BJH Investments (Sussex) Limited | Real estate | 2026 |
| BJH Roofing Services Limited | Construction | 2025 |
| BK Consulting Ltd | Professional & scientific | 2018 |
| BL and GL Properties Limited | Real estate | 2024 |
| Black Belt Leaders Limited | Arts & recreation | 2005 |
| Black Grey White Limited | Administrative & support | 2018 |
| Black Spiral Design Ltd | Other services | 2010 |
| Black TIE (UK) Ltd | Transport & logistics | 2012 |
| Blackbag GTM Services Ltd | Professional & scientific | 2025 |
| Blackbox SEM Ltd | Information & communication | 2019 |
| Blackburn Building & Developments LLP | | 2016 |
| Blackdown Kitchens Ltd | Construction | 2017 |
| Blackmill Place Ltd | Hospitality | 2025 |
| Blackmoor Risk Limited | Financial services | 2026 |
| Blackridge Contracts (UK) Limited | Construction | 2015 |
| Blackwood Designworks Ltd | Professional & scientific | 2023 |
| Blades of Glory Ltd | Extraterritorial | 2024 |
| Blank Canvas Designs Limited | Professional & scientific | 2016 |
| BLB Enterprises Limited | Real estate | 2024 |
| Bleedstoppers International Ltd | Manufacturing | 2021 |
| Blencowe Limited | Real estate | 2019 |
| Blenheims Collectables Ltd | Wholesale & retail | 2004 |
| Blessed Letting Property Investment Ltd | Real estate | 2024 |
| Blik Law Ltd | Professional & scientific | 2025 |
| Blind Faith Tattoo Collective Ltd | Arts & recreation | 2019 |
| Bling Bling Mobile Hand Car Wash & Valeting Ltd | Administrative & support | 2024 |
| Blinkbyte Ltd. | Information & communication | 2014 |
| Block Wealth Management Limited | Professional & scientific | 2010 |
| Blockade Services Limited | Water & waste | 2007 |
| Blockdown Limited | Information & communication | 2024 |
| Bloom Financial Design Limited | Financial services | 2018 |
| Bloom Financial Limited | Financial services | 2025 |
| Blooms by Birth Limited | Extraterritorial | 2024 |
| Bloomsbury Investing Limited | Financial services | 2025 |
| Blossom Al-Warith Limited | Real estate | 2017 |
| Blossom Beauty Boutique Ltd | Other services | 2020 |
| Blossom Boutique Aesthetics and Wellness Clinic Limited | Health & social care | 2024 |
| Blue Aura Property 3 Ltd | Real estate | 2025 |
| Blue Aura Property Ltd | Real estate | 2025 |
| Blue Billboard Ltd | Information & communication | 2020 |
| Blue Bird Aesthetics Ltd | Health & social care | 2023 |
| Blue Build Contractors Limited | Construction | 2022 |
| Blue Building Contractors Limited | Construction | 2014 |
| Blue Castle Studio Ltd | Manufacturing | 2020 |
| Blue Cedars Place Management Company Limited | Households | 1996 |
| Blue Earth Solutions Limited | Professional & scientific | 2005 |
| Blue Flame Vision Limited | Professional & scientific | 2015 |
| Blue Goldstone Holdco Limited | Financial services | 2021 |
| Blue Goldstone Ltd | Construction | 2020 |
| Blue Goldstone Topco Limited | Financial services | 2021 |
| Blue Green Media Digital Limited | Information & communication | 2024 |
| Blue Green Media Limited | Information & communication | 2006 |
| Blue Green Media Publishing Limited | Information & communication | 2024 |
| Blue Kite Tuition Ltd | Education | 2014 |