| Brandland Ltd | Wholesale & retail | 2026 |
| Brasiv Mechanical Ltd | Construction | 2019 |
| Brasoveanu Ltd | Construction | 2015 |
| Brat Autos & Recovery Limited | Wholesale & retail | 2020 |
| Bratu IT Solutions Limited | Other services | 2025 |
| Brave Supply Group Ltd | Wholesale & retail | 2025 |
| Braver Plumbing and Heating Ltd | Construction | 2019 |
| Bravo & Co (UK) Limited | Real estate | 2008 |
| Bravo 1 Investments Limited | Real estate | 2015 |
| Bravo 11 Estates (UK) Limited | Real estate | 2022 |
| Breadfruit Voyage Company Limited | Professional & scientific | 1981 |
| Breal Hair Ltd | Other services | 2023 |
| Breman Healthcare Solutions Ltd. | Health & social care | 2012 |
| Brexter Ltd | Wholesale & retail | 2022 |
| Brezeeclean Ltd | Administrative & support | 2025 |
| Brhm Services Ltd | Water & waste | 2024 |
| Brickmore Limited | Real estate | 2017 |
| Brickup Ltd | Construction | 2026 |
| Bridge and Stone Properties Ltd | Real estate | 2025 |
| Bridge Logistique Cargo Ltd | Wholesale & retail | 2025 |
| Bridlyn & Co Accountancy Ltd | Professional & scientific | 2019 |
| Bridlyn Practical Accountancy Training Ltd | Professional & scientific | 2013 |
| Bright Angels Ltd | Health & social care | 2013 |
| Bright Future Associates Ltd | Professional & scientific | 2018 |
| Bright London Care Limited | Health & social care | 2018 |
| Bright Sparks Tutorial Limited | Education | 2021 |
| Bright Tech Training & Consultancy Ltd | Education | 2020 |
| Brightnest Care Solutions Ltd | Administrative & support | 2025 |
| Brikwiz Ltd | Manufacturing | 2023 |
| Brilliant Construction Ltd | Construction | 2015 |
| Brit Assets Limited | Real estate | 2019 |
| Brit Consultancy Associate Ltd | Professional & scientific | 2019 |
| Britains Beauty Ltd | Wholesale & retail | 2025 |
| Britannia IT Solutions UK Limited | Other services | 2016 |
| Britannia Laundrette 2 Ltd | Other services | 2015 |
| Britannia Offices Ltd | Administrative & support | 2016 |
| Britannia Protection Limited | Administrative & support | 2025 |
| Britannia Wholesalers Ltd | Wholesale & retail | 2014 |
| Britco Buildmart Ltd | Wholesale & retail | 2026 |
| Britfoodcatering Limited | Hospitality | 2025 |
| Britique Haven Ltd | Wholesale & retail | 2023 |
| British Developments Ltd | Real estate | 2004 |
| British Logistics Services Ltd | Transport & logistics | 2012 |
| Briton College Limited | Real estate | 2010 |
| Briton Group Limited | Wholesale & retail | 2019 |
| Britshop Trends Ltd | Wholesale & retail | 2025 |
| Brix Coldharbour Ltd | Real estate | 2022 |
| Brix Developments Ltd | Construction | 2021 |
| Broadline Logistics Limited | Transport & logistics | 2010 |
| Broadway Services Limited | Administrative & support | 2005 |
| Brookdene Consultants Limited | Real estate | 2022 |
| Brookdene Estates Ltd | Real estate | 2025 |
| Brookmove Limited | Other services | 2026 |
| Brooks Landscape Services Ltd | Administrative & support | 2012 |
| Brookshire Limited | Wholesale & retail | 2003 |
| Brothers International Supermarket Limited | Wholesale & retail | 2016 |
| Brown Bean Cafe Ltd | Hospitality | 2026 |
| Browning ABC Limited | Real estate | 2024 |
| Brownings Employee Services LLP | | 2012 |
| Bryant Haulage Co. Ltd | Transport & logistics | 2012 |
| BS Auto Limited | Transport & logistics | 2016 |
| BS Khinda Construction Ltd | Administrative & support | 2025 |
| Bsaa Ltd | Real estate | 2022 |
| BSF Group Ltd | Extraterritorial | 2018 |
| BSL Healthcare Ltd | Administrative & support | 2024 |
| BSS14 Ltd | Real estate | 2026 |
| Bucaj Ltd | Construction | 2019 |
| Buckingham Square Limited | Real estate | 2026 |
| BUD Construct Ltd | Construction | 2023 |
| Budisteanu Construction Ltd | Financial services | 2026 |
| Buflike Solutions Ltd | Administrative & support | 2026 |
| Build 4 21ST Limited | Construction | 2018 |
| Builders Tech Ltd | Construction | 2025 |
| Building Maintain Ltd | Manufacturing | 2023 |
| Buildware Limited | Wholesale & retail | 2015 |
| Bukhari Properties Ltd | Real estate | 2020 |
| Bulbul Builder and DIY Ltd | Construction | 2025 |
| Bulcars Holding Ltd | Transport & logistics | 2017 |
| Bulk Wholesale Ltd | Wholesale & retail | 2025 |
| Bull DIP Limited | Wholesale & retail | 2017 |
| Bulls Group Ltd | Construction | 2017 |
| Bundu Ltd | Hospitality | 2022 |
| Bunkar Limited | Wholesale & retail | 2012 |
| Buon Appetito Limited | Hospitality | 2016 |
| Buramé Recruitment Ltd | Administrative & support | 2019 |
| Buraq Services Ltd | Wholesale & retail | 2025 |
| Burebista Ltd | Wholesale & retail | 2025 |
| Burgers LDN (Barking) Ltd | Hospitality | 2023 |
| Bury Coffee Ltd | Hospitality | 2017 |
| Bush Staffing Limited | Administrative & support | 2026 |
| Business Excellence Management Limited | Professional & scientific | 2017 |
| Business Mind Ltd | Wholesale & retail | 2007 |
| Business Procurement Agencies Ltd | Wholesale & retail | 2026 |
| Business Unlimited Limited | Hospitality | 2017 |
| Businessyield Limited | Transport & logistics | 2023 |
| Busy BEE Healthcare Ltd | Health & social care | 2015 |
| Busy Motors Ltd | Professional & scientific | 2025 |
| Butt & Co. Estates Ltd | Professional & scientific | 2012 |
| Butterella Ltd | Wholesale & retail | 2025 |
| Butterfingers London Ltd | Hospitality | 2022 |