| Beamatica Ltd | Information & communication | 2026 |
| Beamcloud Services Limited | Construction | 2021 |
| Beaumont Recruitment Limited | Transport & logistics | 2019 |
| Beauty Intelligence Group Ltd | Wholesale & retail | 2026 |
| Bebe Foods Ltd | Hospitality | 2013 |
| Beckley Mews Management Company Limited | Households | 2020 |
| Beckmo Ltd | Transport & logistics | 2022 |
| BEE Virdee Ltd | Information & communication | 2023 |
| Beit AL ARZ Limited | Hospitality | 2025 |
| Belgravia Resourcing Limited | Administrative & support | 2025 |
| Bells Box Ltd | Other services | 2022 |
| Beneficia Holding Ltd | Financial services | 2018 |
| Benlin Ltd | Wholesale & retail | 2023 |
| Beon Ltd | Manufacturing | 2026 |
| Besa London Properties Ltd | Real estate | 2025 |
| Bespoke Brushwork Ltd | Construction | 2025 |
| Bespoke Foods Limited | Wholesale & retail | 1982 |
| Best Booze Limited | Wholesale & retail | 2015 |
| Best Brick Traders Ltd | Construction | 2024 |
| Best Care Housing Ltd | Real estate | 2024 |
| Best Microenterprise Limited | Other services | 2025 |
| BESTSALT4LIFE Ltd | Other services | 2025 |
| Bettie Vintage Limited | Wholesale & retail | 2017 |
| BF and TS Limited | Transport & logistics | 2026 |
| BFL Private Limited | Wholesale & retail | 2019 |
| BGG Investment Limited | Real estate | 2025 |
| BGG Traders Limited | Wholesale & retail | 2025 |
| Bhagyoday Trading UK Ltd | Wholesale & retail | 2020 |
| Bhambra Limited | Wholesale & retail | 1996 |
| Bhangu Builders Ltd | Construction | 2022 |
| Bhatti & Sons Building Services Ltd | Construction | 2022 |
| BHV Plastering Limited | Construction | 2015 |
| Bihlogistics Ltd | Transport & logistics | 2025 |
| BIL Catering Ltd | Hospitality | 2018 |
| Billionaire's Dehn AL Oudh Ltd | Wholesale & retail | 2026 |
| Billionairess Cosmetics Ltd | Wholesale & retail | 2025 |
| BIO Aromatics 22 Ltd | Professional & scientific | 2022 |
| Birchwood Lodge Northolt Ltd | Real estate | 2024 |
| Black&White Motor Hire Ltd | Administrative & support | 2022 |
| Black, Green and Gold Limited | Professional & scientific | 2012 |
| Blacktique Ltd | Wholesale & retail | 2025 |
| Blaklite Technical Limited | Arts & recreation | 2018 |
| Blandfords Estates Ltd. | Real estate | 2020 |
| Blended Enterprises Ltd | Information & communication | 2016 |
| Blini Construction Ltd | Construction | 2025 |
| Blockboy Ltd | Transport & logistics | 2014 |
| Bloom Tuition London Ltd | Education | 2025 |
| Bloomcrest Ltd | Real estate | 2024 |
| Blooming Fabulous Landscapes Limited | Construction | 2019 |
| Blue Blacks London Ltd | Manufacturing | 2022 |
| Blue Dubai Limited | Hospitality | 2024 |
| Blueberry Airport Transfer Ltd | Transport & logistics | 2012 |
| Bluestone Developers Ltd | Real estate | 2019 |
| BM Retrofits Limited | Wholesale & retail | 2018 |
| BMB Transformation Ltd | Professional & scientific | 2023 |
| BMG4U Ltd | Construction | 2024 |
| Bnbsouk Ltd | Hospitality | 2026 |
| BOA & BMO Ltd | Real estate | 2022 |
| Boby Ltd | Wholesale & retail | 2025 |
| Body&Barz Limited | Arts & recreation | 2015 |
| Bodymindcoach Ltd | Health & social care | 2024 |
| Bonnie Dogs Pet Services Limited | Other services | 2017 |
| Boomi Ltd | Other services | 2014 |
| Borhan Transport Ltd | Administrative & support | 2024 |
| Bosco Capital Ltd | Real estate | 2025 |
| Bosco Services Ltd | Professional & scientific | 2021 |
| Boswell Stores Limited | Wholesale & retail | 2012 |
| Boxella Ltd | Manufacturing | 2025 |
| BP & MP Limited | Transport & logistics | 2015 |
| BP Studio Ltd | Professional & scientific | 2016 |
| BR Building Services Ltd | Construction | 2024 |
| BR Events Solutions Ltd | Hospitality | 2025 |
| Branched Ltd | Information & communication | 2026 |
| Bravo DA Costa Electrical Limited | Construction | 2020 |
| Braybourne Carriers Ltd | Transport & logistics | 2014 |
| Brayden Hire Ltd | Wholesale & retail | 2021 |
| Breakfastbyamelia Ltd | Hospitality | 2025 |
| Bridge Eight Designs Limited | Professional & scientific | 2018 |
| Bridgepoint Property Group Ltd | Real estate | 2019 |
| Bridgeway Group UK Ltd | Wholesale & retail | 2026 |
| Bridport Operator Ltd | Wholesale & retail | 2020 |
| Bright Futures Haven Limited | Real estate | 2024 |
| Bright N Shine BIN Company Limited | Administrative & support | 2024 |
| Bright N Shine Limited | Construction | 2021 |
| Brightedge Academy Limited | Education | 2017 |
| Brightedge Living Ltd | Wholesale & retail | 2026 |
| Brightstar Consultants Ltd | Professional & scientific | 2022 |
| Brightwave Engineering Ltd | Construction | 2015 |
| Brit Chauffeurs Ltd | Transport & logistics | 2016 |
| Brit Pack Relocations Ltd | Transport & logistics | 2012 |
| Britania Cars Limited | Transport & logistics | 2024 |
| Brooklands Retail Ltd | Wholesale & retail | 2019 |
| Broome Park Hotel Ltd | Hospitality | 2024 |
| Bros Bespoke Stairs Ltd | Construction | 2024 |
| Brothers Build & Finish Limited | Construction | 2024 |
| BSK Logistics Ltd | Transport & logistics | 2025 |
| BSP Property Investments Ltd | Real estate | 2019 |
| Bubbly Green Cleans Limited | Administrative & support | 2025 |
| Build FIX Paint Ltd | Construction | 2018 |
| Build Over Time Ltd | Real estate | 2025 |