| Betterbodyfitness Ltd | Manufacturing | 2014 |
| Between Rituals Ltd | Wholesale & retail | 2026 |
| Bevan Wilson Ltd | Health & social care | 2014 |
| Beverley Mitchell Consulting Ltd | Professional & scientific | 2015 |
| Beverley Sale Ltd | Wholesale & retail | 2016 |
| Beyer Family Law Limited | Professional & scientific | 2011 |
| Beyond the Mirror Ltd | Other services | 2018 |
| BFH Properties Ltd | Real estate | 2025 |
| Bfree Foods Trading UK Limited | Wholesale & retail | 2022 |
| Bgln Limited | Transport & logistics | 2021 |
| Bharatham Fine Arts Academy Ltd | Arts & recreation | 2025 |
| Bhawani Beauty Limited | Other services | 2024 |
| Bhutto's Capital Ltd | Professional & scientific | 2025 |
| Bian Salins Consulting Ltd | Professional & scientific | 2022 |
| Bias 2 Design Ltd | Administrative & support | 2012 |
| Biddles of Guildford Ltd | Wholesale & retail | 2020 |
| Bidnexus Limited | Financial services | 2021 |
| Bien Joué Ltd | Arts & recreation | 2024 |
| Big 5 Investments Limited | Real estate | 2020 |
| Big G Enterprises Limited | Professional & scientific | 2004 |
| Big Lens BAG Limited | Manufacturing | 2024 |
| Bigfoot Creative Limited | Manufacturing | 2016 |
| Bigfoot Inc Limited | Manufacturing | 2011 |
| Bigfoot Print Limited | Professional & scientific | 2018 |
| Bigger Ideas Limited | Professional & scientific | 2013 |
| Biggs Property Management Limited | Real estate | 2026 |
| Bill Frankland Consulting Ltd | Professional & scientific | 2016 |
| Billy Tannery Limited | Manufacturing | 2017 |
| Bimini Animal Health Limited | Manufacturing | 2025 |
| Bincellar Limited | Administrative & support | 2008 |
| Binidido Ltd | Information & communication | 2022 |
| Binocular Bonanza Ltd | Information & communication | 2020 |
| BIO NET Gains Limited | Professional & scientific | 2024 |
| Biochek (UK) Limited | Professional & scientific | 1994 |
| Bioducts Ltd | Professional & scientific | 2018 |
| Biofuel AI Ltd | Information & communication | 2025 |
| Biogas Meden Ltd. | Energy | 2014 |
| Bioglow Limited | Wholesale & retail | 2010 |
| Bioloon Limited | Professional & scientific | 2026 |
| BIOME4PETS Ltd | Professional & scientific | 2025 |
| Biomorphic Ltd | Arts & recreation | 2023 |
| Biprocsi Ltd | Information & communication | 2018 |
| Birchgrove Products Limited | Wholesale & retail | 1988 |
| Birdcage AV Limited | Professional & scientific | 2025 |
| Birtley Courtyard Management Limited | Households | 1999 |
| Birtley Estates Management Limited | Real estate | 2013 |
| Birtley House Group Ltd | Health & social care | 2006 |
| Birtley Mews Limited | Health & social care | 1998 |
| Bishops Garages (Brighton) Limited | Extraterritorial | 1963 |
| Bishops Garth Management Limited | Households | 1980 |
| Bismillaa Ltd | Information & communication | 2026 |
| Bita Property Ltd | Real estate | 2018 |
| Bitalux Limited | Construction | 2023 |
| Bite N Bliss Ltd | Hospitality | 2025 |
| Bits and Pixels Agency Limited | Professional & scientific | 2016 |
| Bitskit Ltd | Education | 2023 |
| Bizarre DEV Ltd | Information & communication | 2025 |
| Bizvu Limited | Professional & scientific | 2003 |
| Bizzctrl Limited | Administrative & support | 2021 |
| BK Petersfield Sushi Ltd | Hospitality | 2022 |
| BKW Consulting Ltd | Professional & scientific | 2011 |
| Black Blocks Limited | Real estate | 2017 |
| Black Castle Holdings Ltd | Real estate | 2022 |
| Black Dear Entertainment Limited | Arts & recreation | 2025 |
| Black Pomegranate Limited | Real estate | 2023 |
| Black Sea Beverages Limited | Wholesale & retail | 2020 |
| Black Sea Capital Ltd | Wholesale & retail | 2019 |
| Blackheath Surrey Cricket Club Limited | Arts & recreation | 2013 |
| Blackhouse & Co Property Ltd | Construction | 2025 |
| Blackwell Park Ltd | Real estate | 2014 |
| Bladon Properties Ltd | Real estate | 2021 |
| Blakes Holdings | Professional & scientific | 2017 |
| Blakes Lane Farm Limited | Agriculture & fishing | 2018 |
| Blanket Mill LLP | | 2007 |
| Blaser Group Ltd | Other services | 2013 |
| Blast the Past (Kent) Ltd | Other services | 2021 |
| Bleach Brothers Limited | Wholesale & retail | 2011 |
| Blend and Beyond Limited | Education | 2023 |
| Bless Start Limited | Manufacturing | 2023 |
| Blipverse Limited | Information & communication | 2023 |
| Blkngroup Ltd | Professional & scientific | 2017 |
| Blocksmart Consulting Ltd | Hospitality | 2019 |
| Bloomsbury Plaza Services Limited | Real estate | 2006 |
| Bloomè Limited | Other services | 2025 |
| BLP Contracts Limited | Arts & recreation | 2013 |
| BLU View Ltd | Professional & scientific | 2023 |
| Blubelt Solutions Ltd | Professional & scientific | 2023 |
| Blue Artech Limited | Construction | 2024 |
| Blue Matrix Business Services Limited | Information & communication | 2013 |
| Blue Moon Advisory Limited | Professional & scientific | 2017 |
| Blue Network Solutions Limited | Information & communication | 2009 |
| Blue Riband Investments Ltd | Real estate | 2005 |
| Blue Sea Star Shipping & Investment Limited | Transport & logistics | 2010 |
| Blue Serene Ltd | Wholesale & retail | 2021 |
| Blue TED Development Limited | Construction | 2011 |
| Blue Tick Tax Advisers & Accountants LLP | | 2023 |
| Blue Tree Recruits Limited | Administrative & support | 2009 |
| BLUE39 Limited | Professional & scientific | 2019 |
| Bluebell Rise Residents Association Limited | Households | 2023 |
| Bluebird Consulting Service Ltd | Information & communication | 2012 |