| AXS Agency Ltd | Real estate | 2019 |
| Ayesh Brother Limited | Administrative & support | 2021 |
| Ayesh London Ltd | Manufacturing | 2024 |
| Ayustech Limited | Information & communication | 2025 |
| Ayyangar Bakery Limited | Wholesale & retail | 2025 |
| Azeon Ltd | Transport & logistics | 2025 |
| Azrl Ltd | Wholesale & retail | 2026 |
| B & a Joinery Limited | Construction | 2016 |
| B & a Woodworking Limited | Construction | 2006 |
| B & G Windows Ltd | Construction | 2008 |
| B and a London Limited | Financial services | 2015 |
| B Tea Limited | Manufacturing | 2020 |
| B&R Cabling Ltd | Construction | 2015 |
| B-Lite Catering Services Ltd | Hospitality | 2025 |
| B. Adkins Construction Limited | Real estate | 1954 |
| B.Marume Wellbeing Ltd | Health & social care | 2019 |
| B.P. Mitchell Haulage Contractors Limited | Construction | 1999 |
| Babatunde CQ Ltd | Wholesale & retail | 2025 |
| BAC Consulting Limited | Information & communication | 2024 |
| Bace Trans Ltd | Transport & logistics | 2018 |
| Bacess Engineering Ltd. | Extraterritorial | 2012 |
| Bacon Bytes Ltd | Information & communication | 2017 |
| BAD Chihuahua Limited | Real estate | 2022 |
| Bajwa Ecom Limited | Wholesale & retail | 2026 |
| Baker Landscape Design Limited | Administrative & support | 2026 |
| Baker Smith Limited | Construction | 2007 |
| Bakers One Ltd | Manufacturing | 2023 |
| Balanceo Ltd | Other services | 2013 |
| Ballas Medical Ltd | Health & social care | 2015 |
| Bamam Limited | Financial services | 2017 |
| Bamberg Interiors Limited | Construction | 2023 |
| Bankchambers Hornsey Management Company Limited | Households | 1995 |
| Bansari Foods Ltd | Wholesale & retail | 2025 |
| Baps Medical Limited | Health & social care | 2019 |
| Bar Crafters Ltd. | Administrative & support | 2019 |
| Baranik Transport Ltd | Transport & logistics | 2019 |
| Barbara Cartland Ebooks Limited | Information & communication | 2012 |
| Barbara Cartland Productions Ltd | Arts & recreation | 2024 |
| Bardophonics Limited | Extraterritorial | 2009 |
| Barhos Developments Ltd | Construction | 2002 |
| Barkingham Palace Pet Grooming Limited | Other services | 2018 |
| Barleywoods Residential Management Limited | Households | 2023 |
| Barnet Elizabethans Rugby Football Club Limited | Arts & recreation | 2010 |
| Barnet Pool Maintenance Limited | Professional & scientific | 2004 |
| Barnet RT Ltd | Real estate | 2023 |
| Barua .ASL Limited | Real estate | 2018 |
| Bassingbourn Fields Management Company Limited | Households | 2020 |
| Batchelor Direct Ltd | Administrative & support | 2025 |
| Batterdale Management Company Limited | Households | 1974 |
| BAW Cargo Ltd | Transport & logistics | 2020 |
| Bay & Bramble Lettings Ltd | Real estate | 2025 |
| Bayford Property Company Limited | Construction | 2023 |
| Bayside Holdings Limited | Financial services | 2021 |
| BBB Entertainments Ltd | Hospitality | 2023 |
| BCC Enterprise Ltd | Financial services | 2024 |
| BCV Property Services Ltd | Real estate | 2021 |
| BDS Films Ltd | Construction | 2024 |
| Beaconsfield Court (Barnet) Management Company Limited | Households | 1971 |
| Beauty by Mandy Ltd | Other services | 2024 |
| Bedfordshire Care Group | Health & social care | 2007 |
| Bedwellbury Limited | Administrative & support | 2013 |
| Bellavita Doors Limited | Wholesale & retail | 2026 |
| Bellus Femina Ltd | Arts & recreation | 2013 |
| Belmondo Building Ltd | Construction | 2013 |
| Belt Healthcare Services Ltd | Administrative & support | 2016 |
| Belyte Limited | Health & social care | 2023 |
| Bengal Spices (Hatfield) Ltd | Hospitality | 2023 |
| Beni Transport Limited | Transport & logistics | 2016 |
| Bensal Group Limited | Information & communication | 2024 |
| Berners Street Lofts Limited | Households | 2016 |
| Berridge Mews Management Company Limited | Households | 1993 |
| Best Foot Forward, Foot Care Ltd | Health & social care | 2024 |
| Best Rates 4 U N ME Ltd | Professional & scientific | 2018 |
| Bestover Limited | Real estate | 1984 |
| Bethel Care Limited | Health & social care | 2022 |
| Bethzatha Care Home Ltd | Public administration | 2022 |
| BETTER4US Ltd | Construction | 2026 |
| Beverix Ltd. | Wholesale & retail | 2022 |
| Bevora Cuvee Ltd | Wholesale & retail | 2026 |
| Beyonk Ltd | Information & communication | 2019 |
| BG Contractors Ltd | Construction | 2024 |
| BG Enache Trans Limited | Transport & logistics | 2016 |
| BG Thame Limited | Hospitality | 2021 |
| BG Tring Limited | Hospitality | 2021 |
| BGS Homes Ltd | Construction | 2024 |
| BHA Property Ltd | Real estate | 2024 |
| Bhana Limited | Professional & scientific | 2025 |
| Bhpp Academy Limited | Arts & recreation | 2021 |
| BID4FURNITURE Ltd | Wholesale & retail | 2012 |
| Biddy's Medicals Ltd | Health & social care | 2026 |
| BIM 99 Limited | Transport & logistics | 2019 |
| BIO Atelier Ltd | Health & social care | 2025 |
| Bioshine Cleaning Services Limited | Administrative & support | 2014 |
| Biosutility Ltd | Construction | 2025 |
| Birchfield Accountants Ltd. | Professional & scientific | 2003 |
| Birchley Limited | Real estate | 2005 |
| Birculescu Trans Ltd | Transport & logistics | 2018 |
| Bishop's Hatfield Girls' School | Education | 2011 |
| Bitatech Ltd | Professional & scientific | 2024 |
| Bitelux Co Ltd | Wholesale & retail | 2026 |