| Brickwall Consultants Limited | Real estate | 2022 |
| Brickwork and Scaffolding Ltd | Construction | 2024 |
| Bridal Services Limited | Other services | 2019 |
| Bridge Road (Cosgrove) Management Limited | Households | 2021 |
| BRIDGE2LIST Ltd | Wholesale & retail | 2020 |
| Bridgegate Tower Limited | Professional & scientific | 2014 |
| Bridgepoint Community | Health & social care | 2025 |
| Bridgepoint Housing Ltd | Other services | 2025 |
| Bridgerock Management Limited | Administrative & support | 2025 |
| Bridgestone Investments Ltd | Real estate | 2025 |
| Bridging Lender Ltd | Financial services | 2019 |
| Briefcases 247 Ltd | Wholesale & retail | 2025 |
| Bright & Smart Electrical Solutions Limited | Construction | 2021 |
| Bright Education Services Limited | Education | 2013 |
| Bright Future Living Ltd | Health & social care | 2025 |
| Bright Futures Construction Limited | Construction | 2012 |
| Bright Light Experience Limited | Other services | 2017 |
| Bright Munchkins Ltd | Financial services | 2018 |
| Bright Path AI Limited | Information & communication | 2025 |
| Bright Red Box Ltd | Administrative & support | 2018 |
| Bright Science Academy Ltd | Education | 2022 |
| Bright Star Childcare Ltd | Health & social care | 2019 |
| Bright Tax Limited | Professional & scientific | 2024 |
| Bright Telecom Ltd | Administrative & support | 2025 |
| Brightcomfort Co. Ltd | Real estate | 2025 |
| Brighter Day Cakes Ltd | Wholesale & retail | 2026 |
| Brighter Education Ltd | Education | 2012 |
| Brighter Path Education Ltd | Education | 2025 |
| Brighthive Online Ltd | Wholesale & retail | 2026 |
| Brightlife Anchor Ltd | Administrative & support | 2025 |
| Brightnest Retail Ltd | Wholesale & retail | 2025 |
| Brighton and Hove Climate Alliance | Professional & scientific | 2023 |
| Brightside London Ltd. | Other services | 2017 |
| Brightway Services Ltd | Information & communication | 2023 |
| Brilliance Blend Limited | Information & communication | 2024 |
| Brilliance Services Limited | Construction | 2008 |
| Brilliant Contractor Ltd | Construction | 2014 |
| Brilliant Touch Cleaning Services Ltd | Administrative & support | 2025 |
| Brilliant Tuition Centre Limited | Education | 2012 |
| Brillpharma Limited | Wholesale & retail | 2011 |
| Brim Brent Cross Ltd | Hospitality | 2025 |
| Brim Burger Luton Ltd | Hospitality | 2022 |
| Brim Burgers Dalston Ltd | Hospitality | 2024 |
| Brim Burgers Hemel Hempstead Ltd | Hospitality | 2023 |
| Brim Hammersmith Ltd | Hospitality | 2025 |
| Brim Ilford Ltd | Hospitality | 2026 |
| Brimat Wellbeing Consultancy Ltd | Health & social care | 2025 |
| Bripat Engineering Limited | Manufacturing | 2007 |
| Brismy Limited | Wholesale & retail | 2025 |
| Brit Cabs Connect Ltd | Administrative & support | 2025 |
| Brit Education Consultant Ltd | Extraterritorial | 2020 |
| Brit Mall Ltd | Wholesale & retail | 2024 |
| Brit Transport Ltd | Transport & logistics | 2019 |
| Britaly Post Limited | Information & communication | 2013 |
| Britannia Apparel Limited | Wholesale & retail | 2020 |
| Britannia Beauty Bar Ltd | Other services | 2022 |
| Britannia Decorators Luton Ltd | Construction | 2023 |
| Britannia Hosting Limited | Information & communication | 2020 |
| Britannia Investments Luton Ltd | Other services | 2022 |
| Britannia Restaurants Ltd | Hospitality | 2026 |
| Britannia Soft Limited | Information & communication | 2023 |
| Britannia TEL Limited | Information & communication | 2020 |
| Britecloud UK Ltd | Information & communication | 2019 |
| Brites Associates Limited | Administrative & support | 2012 |
| British School of Aviation Ltd | Education | 2018 |
| British Shuai Jiao Union Ltd | Wholesale & retail | 2021 |
| Britishcraze Limited | Wholesale & retail | 2024 |
| Britnnovate Limited | Wholesale & retail | 2025 |
| Brito Trades Ltd | Wholesale & retail | 2025 |
| Brittrend Store Ltd | Wholesale & retail | 2025 |
| Brndx Marketing Services Ltd | Professional & scientific | 2025 |
| Broad Balti Ltd | Hospitality | 2025 |
| Broad Brickwork VB Limited | Construction | 2022 |
| Broad Mount Holdings Limited | Financial services | 2025 |
| Broad Peak Group Ltd | Wholesale & retail | 2026 |
| Broadeaves Consulting Limited | Professional & scientific | 2016 |
| Broadmead Lettings Limited | Real estate | 2018 |
| Broadmead Properties Limited | Construction | 2013 |
| Broadoak Flats (Luton) Limited | Households | 1976 |
| Broadstone Group UK Limited | Information & communication | 2021 |
| Brockmore Sales and Lettings London Limited | Households | 2023 |
| Brogan Trading Ltd | Wholesale & retail | 2026 |
| Bromell Mining LLP | | 2025 |
| Bromham Developments (Southern) Ltd | Construction | 2025 |
| Brompton Care Services Ltd | Health & social care | 2019 |
| Brook Base Limited | Other services | 2018 |
| Brooke Homes (Bicester) Limited | Construction | 2014 |
| Brooke Homes Consulting Limited | Professional & scientific | 2015 |
| Brooke Homes Limited | Construction | 1984 |
| Brookefield Limited | Real estate | 2021 |
| Brooklands Square Holdings Limited | Real estate | 2025 |
| Bros & Sons Ltd | Construction | 2023 |
| Brother 2 Brother WE Stand C.I.C. | Health & social care | 2026 |
| Brotherapy Ltd | Health & social care | 2025 |
| Brotherhood Cuts Limited | Other services | 2026 |
| Brotherly Homes Ltd | Real estate | 2021 |
| Brothers Foods Ltd | Wholesale & retail | 2020 |
| Brow Bar & Beauty Clinic Ltd | Other services | 2023 |
| Brow Bar Clinic Ltd | Other services | 2024 |
| Brow Cosmetics Ltd | Wholesale & retail | 2020 |