| Avertiz Limited | | 2010 |
| Avid Services Ltd | Construction | 2015 |
| Awow Services Limited | Other services | 2024 |
| Axtel & Co Limited | Wholesale & retail | 2026 |
| Axtel Capital Partners Limited | Financial services | 2026 |
| Ayassessments Ltd | Public administration | 2023 |
| Azaria Capital Ltd | Administrative & support | 2023 |
| Azaria Consulting Ltd | Administrative & support | 2021 |
| Azir Ltd | Wholesale & retail | 2012 |
| Azotro Capital Ltd | Administrative & support | 2026 |
| Azura Freehold Limited | Real estate | 2024 |
| Azure Motor Company Limited | Wholesale & retail | 2025 |
| Azure Property Management Limited | Real estate | 2025 |
| B & JT Holdings Ltd | Professional & scientific | 2020 |
| B Baker Consultancy Ltd | Professional & scientific | 2026 |
| B Baker Holdings Ltd | Financial services | 2026 |
| B D Venue Trading Limited | Administrative & support | 2022 |
| B G Displays Limited | Construction | 2010 |
| B Y Flooring Limited | Construction | 2018 |
| B&D2020 Ltd | Wholesale & retail | 2020 |
| B-Hub Chemanalytics Ltd | Information & communication | 2025 |
| B.A.G Services (Cheshunt) Limited | Financial services | 2013 |
| B.M. Trevillion Interiors Limited | Administrative & support | 1978 |
| B.R. Needham (Financial Services) Limited | Financial services | 1990 |
| B.R.M. Contractors Limited | | 1979 |
| B2 Bridging LLP | | 2016 |
| B4BS Investments Ltd | Financial services | 2016 |
| Baby Beautiful Company Ltd | Wholesale & retail | 2020 |
| Back to Health Hertford Ltd | Health & social care | 2021 |
| BAD Films B13 Limited | Information & communication | 2024 |
| BAD Films Gtts Limited | Information & communication | 2024 |
| BAD Films Limited | Information & communication | 2024 |
| Badger Computer Services Limited | Information & communication | 1997 |
| Badger Controls Limited | Construction | 2001 |
| Badgers Close Management Company Limited | Households | 1987 |
| Baggaley Commercial Services Ltd | Professional & scientific | 2010 |
| Bahtiyar Limited | Hospitality | 2014 |
| Baileys Builders Group Ltd | Construction | 2025 |
| Bailiwick Botanicals (UK) Limited | Health & social care | 2022 |
| Bailwood Painting Limited | Construction | 2020 |
| Baitcraft Ltd | Wholesale & retail | 2016 |
| Balance Creative Ltd | Professional & scientific | 2011 |
| Balcombe Developments Limited | Construction | 2006 |
| Baldock Care Ltd | Health & social care | 2012 |
| Balfour Chauffeur Services Limited | Transport & logistics | 2018 |
| Ballard Court Residents Company Limited | Households | 2006 |
| Balletforce Ltd | Education | 2023 |
| Balls Park Apartments Management Company Limited | Households | 2010 |
| Balls Park Mansion Management Company Limited | Households | 2010 |
| Balls Park Mansion RTM Company Limited | Households | 2017 |
| Balls Park Residents Company Limited | Households | 2004 |
| Balway Property Services Group Ltd | Construction | 2024 |
| Bamboo Fundraising Ltd | Administrative & support | 2015 |
| Bandarband Ltd | Wholesale & retail | 2012 |
| Bang Face Limited | Arts & recreation | 2007 |
| Bar-B-Q Enterprises Limited | Construction | 1959 |
| Barbican Financial Advisors Limited | Professional & scientific | 2002 |
| Barbican Independent Financial Advisors Limited | Financial services | 1987 |
| Barick Ltd | Wholesale & retail | 2021 |
| Barker & Borlase Limited | Agriculture & fishing | 1944 |
| Barkingham Palace Retreat Ltd | Professional & scientific | 2023 |
| Barley Grove Investments Limited | Administrative & support | 2020 |
| Barlow Interventions Limited | Administrative & support | 2009 |
| Barnet Lock & Tindall Security Group Ltd | Administrative & support | 2026 |
| Barnet Lock and Security Limited | Wholesale & retail | 2001 |
| Barnyard Professional Grooming Salon & Spa Ltd | Other services | 2026 |
| Baron Compliance Limited | Professional & scientific | 2026 |
| Baronguard Limited | Information & communication | 1984 |
| Barristers for Business Limited | Professional & scientific | 2013 |
| Bartech UK Limited | Wholesale & retail | 1998 |
| Barton Bridging Limited | Other services | 2019 |
| Barton Commercial Group Limited | Administrative & support | 2018 |
| Barton Evolution Limited | Other services | 2019 |
| Barton Solutions Limited | Real estate | 2011 |
| Base (Acton) Management Company Limited | Households | 2005 |
| Batch Content Ltd | Information & communication | 2024 |
| Batchwood Aviation Limited | Administrative & support | 2023 |
| Batik Road Management Company Limited | Real estate | 2023 |
| Battiston Consulting Ltd | Extraterritorial | 2012 |
| Bay Hale Investments Ltd | Financial services | 2023 |
| Bayford Hale Limited | Administrative & support | 2021 |
| Bayford Hall Farm Limited | Arts & recreation | 2022 |
| Bayford Pre-School | Education | 2011 |
| Bayfordbury Estates Limited | Construction | 1991 |
| Bayfordbury Mansion Limited | Households | 2007 |
| Bayl Holdings Limited | Professional & scientific | 2016 |
| Bayley Hall Rentals Ltd | Real estate | 2019 |
| Bazan Corporation Ltd | Administrative & support | 2012 |
| Bazz Enterprise Limited | Hospitality | 2025 |
| BB Classic Vehicles Limited | Wholesale & retail | 2025 |
| BBA Catering Limited | Hospitality | 2017 |
| BBD Electrical Contractors Ltd | Construction | 2017 |
| BBL (Holdings) Limited | Professional & scientific | 2006 |
| BC TMA Limited | Real estate | 2015 |
| BCC Property Limited | Administrative & support | 2015 |
| BCS (QS) Ltd | Professional & scientific | 2025 |
| BCS Building Services Ltd | Construction | 2025 |
| BCS Support Services Ltd | Construction | 2024 |
| Bcsl Solutions Limited | Professional & scientific | 2010 |
| BCW Sports Services Limited | Arts & recreation | 2012 |