| Awareness for Everyone CIC | Health & social care | 2026 |
| AWB Carpentry and Building Services Limited | Construction | 2011 |
| AWB Construction Services Limited | Financial services | 2024 |
| Awps Mechanical Ltd | Construction | 2009 |
| Axis Engineering Solution Limited | Construction | 2019 |
| Axisland Limited | Real estate | 2000 |
| Ayaat Teletronics Ltd | Information & communication | 2017 |
| Ayani Consultancy Ltd | Other services | 2023 |
| Aylesbury Home Lettings Limited | Real estate | 2021 |
| Ayot Property and Business Enterprises Limited | Real estate | 2015 |
| Aytas Info Limited | Information & communication | 2018 |
| Azaan Hospitality Limited | Hospitality | 2024 |
| Azaan Trading London Limited | Hospitality | 2023 |
| Azanis Ltd | Health & social care | 2016 |
| AZM Luxe Ltd | Real estate | 2026 |
| Azure Security Group Limited | Administrative & support | 2023 |
| B & N Food Centre Limited | Wholesale & retail | 2019 |
| B & R Property Services Limited | Administrative & support | 2009 |
| B a Consulting Limited | Professional & scientific | 2005 |
| B Maintenance Ltd | Construction | 2025 |
| B O'Riordan Limited | Construction | 2015 |
| B Property Ltd | Real estate | 2024 |
| B Quick Transport Ltd | Transport & logistics | 2021 |
| B S B Foods Ltd | Wholesale & retail | 2019 |
| B&M&L Trans Ltd | Transport & logistics | 2026 |
| B&S Capital Ventures Limited | Real estate | 2024 |
| B&S Motors Limited | Wholesale & retail | 2023 |
| B'S Online Limited | Wholesale & retail | 2019 |
| B.T.C Builders and Contractors Ltd | Manufacturing | 2025 |
| B2B Nexus Partners Limited | Information & communication | 2023 |
| B2KB Limited | Administrative & support | 2016 |
| B9 International Limited | Extraterritorial | 2017 |
| BA Bespoke Automotive Limited | Wholesale & retail | 2023 |
| Baan Chuenchai Thai Massage Ltd | Health & social care | 2020 |
| Baby'Laijh Limited | Wholesale & retail | 2019 |
| Bacabo Ltd | Transport & logistics | 2025 |
| BAD Scientist LLP | | 2026 |
| Badalutaanddaughter Limited | Transport & logistics | 2023 |
| Badpersgo Ltd | Wholesale & retail | 2026 |
| Badrian Consulting Limited | Construction | 2009 |
| Baicu Transport Ltd | Transport & logistics | 2025 |
| Bailey Sparks Ltd | Construction | 2019 |
| Bajaj Traders Ltd | Wholesale & retail | 2015 |
| Baked N Loaded Ltd | Hospitality | 2025 |
| Baker and SON Engineering Limited | Construction | 2016 |
| Baker Sales and Lettings Limited | Real estate | 2009 |
| Balance Fitt Property Limited | Real estate | 2024 |
| Balanced Flames Ltd | Manufacturing | 2024 |
| Balguard Holdings Limited | Financial services | 2020 |
| Ballaspur Consultancy Ltd | Information & communication | 2023 |
| Ballownumble Limited | Real estate | 2024 |
| Bamboo Wellness for Women Ltd | Health & social care | 2025 |
| Banana Blossom Ltd | Hospitality | 2023 |
| Banana Shaikh Limited | Real estate | 2025 |
| Bandin Limited | Real estate | 2019 |
| Bangla Town Business Limited | Other services | 2022 |
| Bangladesh Investment Group Limited | Administrative & support | 2023 |
| Bansal Brothers Limited | Financial services | 2017 |
| Bansal Holdings (Hythe) Limited | Real estate | 2021 |
| Bansberia Limited | Professional & scientific | 2002 |
| Bansid Limited | Real estate | 2020 |
| Banstead Trading Co Limited | Administrative & support | 2019 |
| Bapsandpitta Ltd | Hospitality | 2024 |
| Barakah Oxford Limited | Hospitality | 2015 |
| Barbar Time Ltd | Other services | 2025 |
| Barberastrans Ltd | Administrative & support | 2016 |
| Bargain Stock Ltd | Wholesale & retail | 2016 |
| Bari GAW Limited | Hospitality | 2024 |
| Barlow Close Limited | Hospitality | 2016 |
| Barnachea Media Ltd | Information & communication | 2023 |
| Barnesclay Solutions Ltd | Professional & scientific | 2018 |
| Barry Brickwork Limited | Extraterritorial | 2014 |
| Barth Consulting Limited | Professional & scientific | 2016 |
| Barton Silver Spoon Ltd | Hospitality | 2024 |
| Barworth Building Consultancy LLP | | 2025 |
| BAS & Sons Properties Limited | Real estate | 2025 |
| Basha Engineering Limited | Construction | 2016 |
| Basils Farm Ltd | Education | 2020 |
| Bassett Properties Limited | Construction | 2013 |
| Bastovium Consulting Limited | Professional & scientific | 2025 |
| Baxlaw Consulting Limited | Professional & scientific | 2008 |
| Bay Tree Cottage Properties Ltd | Households | 2025 |
| Bayntun Consulting Limited | Professional & scientific | 2013 |
| BBG Capital Corporation UK Limited | Professional & scientific | 2020 |
| Bbrc Care Time Cleaning Ltd | Administrative & support | 2025 |
| Bbrc Care Time Ltd | Health & social care | 2016 |
| BBS Accountancy Services Ltd | Professional & scientific | 2026 |
| BBS Logistics Ltd | Administrative & support | 2019 |
| BBS Recruitments (Southern) Ltd | Administrative & support | 2019 |
| BC Interiors Limited | Construction | 2019 |
| Bc&G Care Homes Limited | Health & social care | 2004 |
| BDS Builders Ltd | Construction | 2019 |
| BE Beautiful Lashes Beauty & Aesthetics Ltd | Other services | 2022 |
| BE Safe Fire Protection Limited | Manufacturing | 2007 |
| Beacon Hill Ltd | Real estate | 2024 |
| Beaconsfield Coffee Shop Limited | Professional & scientific | 1979 |
| Beaconsfield Delight Limited | Hospitality | 2018 |
| Bearbrook Limited | Financial services | 2020 |
| Beards & Barbers Limited | Other services | 2017 |
| Beata MED Consultancy Ltd | Health & social care | 2021 |