| Atrophy Games Ltd | Information & communication | 2022 |
| Atterbury Thomas Consulting Limited | Professional & scientific | 2011 |
| Atticus Investment Holdings Ltd | Financial services | 2023 |
| Atticus Properties II Ltd | Real estate | 2025 |
| Atticus Properties Ltd | Real estate | 2023 |
| Attractive Marketing Limited | Other services | 2011 |
| AU Yeung Consulting Ltd | Information & communication | 2024 |
| Audas International Management Consultancy Limited | Professional & scientific | 2005 |
| Augurer Limited | Professional & scientific | 2022 |
| Auguru Limited | Financial services | 2022 |
| Augustine Nominees Ltd. | Professional & scientific | 2016 |
| Augustine Private Client Services Limited | Administrative & support | 2015 |
| Augustine Tax Limited | Professional & scientific | 2021 |
| Austec Fleet Services Ltd | Wholesale & retail | 2014 |
| Auto Body Language Limited | Wholesale & retail | 1994 |
| Autoeurope (Properties) Limited | Real estate | 1989 |
| Autoeurope (UK) Ltd | Manufacturing | 2015 |
| Available Lawyers Ltd | Information & communication | 2014 |
| Avalt Limited | Financial services | 2026 |
| Avante Marketing Limited | Professional & scientific | 2016 |
| Avanti Refurb Services Limited | Construction | 2019 |
| Avoca Systems Consulting Limited | Professional & scientific | 2026 |
| Avocado Audio Visual Services Ltd | Administrative & support | 2014 |
| AWB Surveyors Ltd | Construction | 2020 |
| Axiom Oxford Medical Ltd | Health & social care | 2025 |
| AXO Consulting Ltd | Professional & scientific | 2025 |
| Ayacare Limited | Wholesale & retail | 2025 |
| Azah Properties Ltd | Real estate | 2023 |
| Azlan Data Limited | Information & communication | 2026 |
| B.M. Equine Services Limited | Administrative & support | 2003 |
| B.R.L. Estates Limited | Real estate | 1995 |
| Babeease Ltd | Manufacturing | 2025 |
| Back to the Past Limited | Extraterritorial | 2009 |
| Backup Accounting Limited | Professional & scientific | 2025 |
| Bakehouse Communications Limited | Professional & scientific | 2009 |
| Baker Wilkins & Smith (Bahrain) Limited | Professional & scientific | 2021 |
| Baker Wilkins & Smith Holdings Limited | Professional & scientific | 2018 |
| Baker Wilkins and Smith Limited | Professional & scientific | 2008 |
| Baker Wilkins Limited | Professional & scientific | 2018 |
| Baker's Radio Limited | Wholesale & retail | 1961 |
| Balance Media Ltd | Information & communication | 2007 |
| Balanced Resources Limited | Professional & scientific | 2010 |
| Baldock Energy Ltd | Professional & scientific | 2019 |
| Ballamy & Partners Limited | Professional & scientific | 2013 |
| Ballamy LLP | | 2013 |
| Ballen Homes Ltd | Construction | 2011 |
| Bandmode Computers Limited | Information & communication | 1990 |
| Bansha (UK) Limited | Real estate | 2000 |
| Baqland Ltd | Water & waste | 2020 |
| Barde Building Consultants Limited | Construction | 2026 |
| Barentz UK Limited | Wholesale & retail | 1983 |
| Barkworth Associates Limited | Professional & scientific | 2011 |
| Barlin Investments Limited | Professional & scientific | 1977 |
| Barnes Electrical Limited | Construction | 2002 |
| Barnham Solutions Ltd | Professional & scientific | 2014 |
| Bars Contractors Southern Ltd | Construction | 2011 |
| Barvet Limited | Professional & scientific | 2017 |
| Basil's of Reigate Ltd | Hospitality | 2024 |
| Bathroom and Plumbing Superstore Limited | Wholesale & retail | 2004 |
| Bathroom and Plumbing Supplies Limited | Wholesale & retail | 2018 |
| Baton App Ltd | Transport & logistics | 2025 |
| Batten Architectural Ltd | Construction | 2025 |
| Bay Fish Bar Ltd | Hospitality | 2019 |
| BB City Ltd | Other services | 2022 |
| Bbak Business Holding Ltd | Financial services | 2026 |
| Bbak Business Ltd | Education | 2024 |
| Bchmp Owners Limited | Households | 1998 |
| BDE Partnership Ltd | Construction | 2025 |
| BDL (Ascot) Limited | Construction | 2010 |
| BE Different Limited | Professional & scientific | 2003 |
| Beach HUT Films Limited | Information & communication | 2005 |
| Beacon Travel Ltd | Administrative & support | 2011 |
| Beaconhouse Educational Services Limited | Administrative & support | 2003 |
| Beaconhouse Educational Support Services Ltd | Education | 2023 |
| Bear IP Ltd | Professional & scientific | 2025 |
| Bearbridge Tax Recruitment Ltd | Administrative & support | 2025 |
| Beaufort (Limes) Limited | Construction | 2021 |
| Beaufort Homes Limited | Construction | 2019 |
| Beauty Status Ltd | Other services | 2022 |
| Beaverbrook Properties Ltd | Real estate | 2024 |
| Bedferret Ltd | Information & communication | 2018 |
| Bedford Bailey Limited | Professional & scientific | 2017 |
| Beech BJ Build Ltd | Construction | 2023 |
| Beechmount Procurement Services Limited | Professional & scientific | 2023 |
| Beecholme (Welwyn) Management Company Limited | Households | 2022 |
| Beesley Estates Limited | Real estate | 2023 |
| Behind the Lines (MS M T Roberts) Limited | Professional & scientific | 2013 |
| Beltane Close Residents Limited | Households | 2013 |
| BEN Billy & Sing's Company Ltd | Administrative & support | 2025 |
| Ben's Production Company Limited | Information & communication | 2012 |
| Benriches Nominees Limited | Extraterritorial | 1976 |
| Benting Mead Limited | Households | 2025 |
| Bern Pet Foods Limited | Wholesale & retail | 2009 |
| Beroea Limited | Health & social care | 2010 |
| Bespoke Business Software Ltd | Information & communication | 2017 |
| Best Coulsdon Tailor Ltd | Other services | 2026 |
| Bettahomes Limited | Wholesale & retail | 2003 |
| Betty and Bertie Ltd | Wholesale & retail | 2024 |
| Beulah CT Albert Road RTM Company Ltd | Households | 2024 |
| Bewm Ltd | Professional & scientific | 2024 |