| Ashnova Ltd | Information & communication | 2025 |
| Ashray Properties Limited | Real estate | 2021 |
| Ashvale Construction Services Ltd | Construction | 2020 |
| Asia UK Property Fund LLP | | 2010 |
| Aslan Fire Safety Services Limited | Administrative & support | 2016 |
| Aspire Group Property Developments Ltd | Construction | 2023 |
| Association of Women in the Arts | Other services | 2017 |
| Astl Sales Limited | Wholesale & retail | 2024 |
| Astonmoor Limited | Other services | 2025 |
| Astra Consulting Limited | Professional & scientific | 2013 |
| Atarbo Engineering Ltd | Construction | 2022 |
| ATE Civil & Structural Engineering Ltd | Construction | 2022 |
| Atelier - SM (Architects) Limited | Professional & scientific | 2004 |
| Atlas Global Logistics Ltd | Transport & logistics | 2016 |
| Attwood Services Limited | Energy | 2009 |
| Aurelia Investments Ltd | Real estate | 2025 |
| Austin Chapel Equity Release LLP | | 2009 |
| Austin Chapel Estate Planning LLP | | 2025 |
| Austin-Chapel Independent Financial Advisers LLP | | 2009 |
| Auto and Transport Ltd | Transport & logistics | 2026 |
| Avalon Group Ltd | Construction | 2022 |
| Avalon Pharma Consultancy Limited | Professional & scientific | 2019 |
| Aventurine Accounting Ltd | Professional & scientific | 2019 |
| Aventurine Accounting Solutions Ltd | Professional & scientific | 2014 |
| Aventus Consultants Ltd | Professional & scientific | 2023 |
| Avenue Improvements Ltd | Construction | 2021 |
| Avlis Porte Limited | Wholesale & retail | 2024 |
| AVM Joinery Ltd | | 2014 |
| Avonrose Ltd | Construction | 2020 |
| AWS Accountants (London) LLP | | 2024 |
| AWS Accountants Services Ltd | Administrative & support | 2024 |
| Axis Build Consulting Ltd | Professional & scientific | 2026 |
| Axis Photonics Limited | Wholesale & retail | 2001 |
| Ayaz Tailoring Limited | Manufacturing | 2017 |
| Ayuryama Wellness UK Ltd | Wholesale & retail | 2021 |
| Azure Roofing Ltd | Construction | 2013 |
| B & E Ltd | Hospitality | 2010 |
| B H Carpenters Limited | Construction | 2014 |
| B M Wells Consultancy Ltd | Professional & scientific | 2024 |
| B S K Builders Ltd | Construction | 2021 |
| B2 Live Events Ltd | Administrative & support | 2018 |
| Baby Sensory (Romford) Limited | Education | 2016 |
| Baby Sensory Brentwood Ltd | Education | 2017 |
| Baddow Consulting Ltd | Professional & scientific | 2014 |
| Bajib Limited | Construction | 2024 |
| Baker Consulting Services Limited | Professional & scientific | 2023 |
| Baldwins Farm (Essex) Ltd | Real estate | 2025 |
| Baldwins Farm Ltd | Real estate | 2025 |
| Balearic Drinks Ltd | Wholesale & retail | 2021 |
| Balfour Properties (Essex) Limited | Real estate | 2018 |
| Baltic and European Shipping Limited | Transport & logistics | 1988 |
| Banff Property Limited | Construction | 2022 |
| Bannerman Consulting Engineers Ltd. | Other services | 2002 |
| Bannister Procurement Limited | Administrative & support | 2007 |
| Banzac UK Limited | Wholesale & retail | 2018 |
| Barcia Virtual Solutions Ltd | Administrative & support | 2025 |
| Barford Industries Limited | Manufacturing | 2002 |
| Barn Life Ltd | Real estate | 2021 |
| Barnicle IT Limited | Information & communication | 2011 |
| Basil Business Ltd | Professional & scientific | 2019 |
| Batestone Limited | Professional & scientific | 2017 |
| Battlegate Limited | Real estate | 2022 |
| Bayo Driving College Limited | Education | 2017 |
| Baytree Court Opco Limited | Health & social care | 1994 |
| BC3 Investments Limited | Financial services | 2025 |
| BCE Productions Ltd | Professional & scientific | 2024 |
| BDL Logistics Ltd | Transport & logistics | 2018 |
| BDP Consulting Limited | Professional & scientific | 2011 |
| BEA Grocery Ltd | Hospitality | 2026 |
| Beacon and Oasis Ltd | Real estate | 2024 |
| Beaulah Care Limited | Health & social care | 2017 |
| Bee-Nutritious Ltd | Health & social care | 2020 |
| Beforeyourbuild Limited | Professional & scientific | 2026 |
| Behaviour Change Network Limited | Information & communication | 2022 |
| Bella Estates Limited | Households | 2023 |
| Bellanath Ltd | Real estate | 2020 |
| Belmont Trade and Commerce LLP | | 2007 |
| Belmont Trade Associates Limited | Professional & scientific | 2011 |
| Benson James Limited | Financial services | 2014 |
| Berbro Heights Limited | Real estate | 2022 |
| Berbro Properties Ltd | Real estate | 2022 |
| Berzan Cafe Ltd | Hospitality | 2018 |
| Best Choice Investment Ltd | Real estate | 2013 |
| Beta. Climbing Gear Limited | Manufacturing | 2025 |
| Better Build Property Group Ltd | Real estate | 2024 |
| Better Build Property Holdings Ltd | Real estate | 2025 |
| Better Build Property LLP | | 2026 |
| Better Build Property Services Ltd | Real estate | 2024 |
| Better Late Than Never Limited | Administrative & support | 2023 |
| Better Performance Services Ltd | Arts & recreation | 2023 |
| Better: Health & Performance Ltd | Health & social care | 2023 |
| Betty's Bits and Bobs Limited | Wholesale & retail | 2018 |
| BHE Consultants Ltd | Extraterritorial | 2011 |
| Big Blue Gazelle Limited | Professional & scientific | 2025 |
| Bilby Electrical Limited | Construction | 2014 |
| Birch Screeding Ltd | Construction | 2008 |
| Birmingham Business Park Properties LLP | | 2010 |
| Bitefull Limited | Hospitality | 2025 |
| BJC Studios Ltd | Arts & recreation | 2020 |
| Black Diamond Auto Logistics Ltd | Transport & logistics | 2026 |