| Aspect Surveyors Limited | Real estate | 2010 |
| Aspect Wood Management Company Ltd | Administrative & support | 2018 |
| Aspen Place Residents Company Limited | Households | 2002 |
| Asquith House RTM Company Limited | Households | 2024 |
| Asset Leasing Limited | Extraterritorial | 2005 |
| Associated Lead Mills Ltd. | Wholesale & retail | 1997 |
| Associated Lead Products Ltd. | Wholesale & retail | 1997 |
| Assurability CIC | Professional & scientific | 2012 |
| Aston Court (Oldbury) Management Company Limited | Households | 2005 |
| Astonbury Manor (NO.2) Limited | Households | 1992 |
| Astor Place Management Company Limited | Households | 2006 |
| Asucaris Ltd | Real estate | 2021 |
| Asure Limited | Construction | 2024 |
| ATA Engineering Products Limited | Wholesale & retail | 2021 |
| ATD Group Holdings Limited | Financial services | 2022 |
| ATD Investments Plus Limited | Real estate | 2021 |
| ATD Structures Ltd | Construction | 2013 |
| Atelier DE Beaute Ltd | Wholesale & retail | 2026 |
| Athenia Close Management Limited | Households | 2001 |
| Atherley Fields (Southampton) Management Limited | Households | 1998 |
| Atlanta Rose Lettings Ltd | Real estate | 2022 |
| Attenboroughs (Accountants) Limited | Professional & scientific | 2016 |
| Attenboroughs Probate and Wills Ltd | Professional & scientific | 2018 |
| Audar Health Technology Ltd | Professional & scientific | 2025 |
| August International Ltd | Wholesale & retail | 2005 |
| Augustine's Well Residents Company Limited | Households | 2004 |
| Aura 77 Limited | Wholesale & retail | 2007 |
| Auro AI Ltd | Information & communication | 2025 |
| Autonomy Finance Ltd | Professional & scientific | 2022 |
| AVA Academy Ltd | Education | 2020 |
| Avanti & Co Developments Ltd | Construction | 2021 |
| Avenue Heights (Surbiton) Management Company Limited | Households | 2005 |
| Averie Limited | Education | 2012 |
| Avonhill Consulting Ltd | Professional & scientific | 2021 |
| AVS Solutions Ltd | Construction | 2021 |
| AWD Investments Limited | Real estate | 2023 |
| AWT Studios Ltd | Information & communication | 2016 |
| AYA Systems Ltd | Transport & logistics | 2024 |
| Ayes Management Company Limited | Households | 1995 |
| Ayko Creations Limited | Arts & recreation | 2021 |
| Ayurveda Awakening Ltd | Health & social care | 2024 |
| AZ Leases Ltd | Real estate | 2024 |
| B & H Cars of Herts Limited | Transport & logistics | 2024 |
| B B D Blinds Limited | Other services | 2002 |
| B P Car Repairs Ltd | Wholesale & retail | 2012 |
| B R L Group Limited | Professional & scientific | 2017 |
| B&H Executive Taxi Ltd | Transport & logistics | 2025 |
| B&T Vehicle Hire Limited | Administrative & support | 2023 |
| B. Thompson Limited | Wholesale & retail | 1953 |
| Baberties Ltd | Real estate | 2025 |
| Bacberg Consulting Limited | Professional & scientific | 2026 |
| Back Beach Fitness Limited | Arts & recreation | 2025 |
| Back Lane (Guiseley) Management Company Limited | Households | 2003 |
| Backes & Strauss Limited | Administrative & support | 2006 |
| BAD Berries Ltd | Professional & scientific | 2018 |
| Bader Heights (Tangmere) Management Company Limited | Households | 2015 |
| Bailey Green (Malpas) Management Company Limited | Households | 2025 |
| Bain and Balshaw Limited | Construction | 2007 |
| Bakers Fire Safety Consultancy Limited | Administrative & support | 2022 |
| Ballinteen Property Ltd | Real estate | 2024 |
| Balmoral Avenue (Beckenham) Management Company Limited | Households | 1995 |
| Baltic Quay Leaseholders Limited | Households | 2002 |
| Banana Lettings Ltd | Real estate | 2020 |
| Bangura Solutions Limited | Administrative & support | 2018 |
| Banks Bespoke Builds. Limited | Manufacturing | 2024 |
| Bannermans Catering Ltd | Manufacturing | 2018 |
| Banu Trans Ltd | Transport & logistics | 2019 |
| Barallen Creative Services Limited | Professional & scientific | 2011 |
| Barba Investments Ltd | Real estate | 2019 |
| Barbrook Estates Ltd | Real estate | 2026 |
| Bard & Blackwood Limited | Administrative & support | 1984 |
| Bard & Brazier Limited | Manufacturing | 1979 |
| Bardolph Aero Tooling Limited | Wholesale & retail | 2026 |
| Bargain Biker Bits Ltd | Wholesale & retail | 2024 |
| Barker BUS Limited | Wholesale & retail | 2013 |
| Barley Rise (Ashington) Management Company Limited | Households | 2004 |
| Barnes & Sons Electrical Services Limited | Construction | 2009 |
| Barracuda London Limited | Extraterritorial | 2015 |
| Barrett Road (Block B) Management Company Limited | Households | 1991 |
| Barrington Way (Hatfield) Management Company Limited | Households | 2004 |
| Barton Quarter (Horwich) Residents Management Company Limited | Households | 2022 |
| Basset Road Management Limited | Real estate | 2025 |
| Bassett Wood Mews Management Limited | Households | 1988 |
| Bath Place (Winchester) Limited | Households | 2005 |
| Bathroom Spare Parts Ltd | Wholesale & retail | 2023 |
| Bay Digital Consulting Limited | Professional & scientific | 2018 |
| Bben Property Services Limited | Financial services | 2015 |
| BCD Elite Security Ltd | Administrative & support | 2024 |
| BCM Trans Ltd | Transport & logistics | 2016 |
| BD Mortgage Group Ltd | Financial services | 2022 |
| BDA Pipe Work Services Limited | Construction | 2025 |
| BDW Properties Ltd | Real estate | 2018 |
| Beacon Business Group Ltd | Real estate | 2020 |
| Bealls Carpentry & Building Services Ltd | Construction | 2017 |
| Beaulieu Grange Residents Association Limited | Professional & scientific | 1998 |
| Beaumont Road Residents Management Limited | Households | 1988 |
| Beauty Buys Limited | Wholesale & retail | 2016 |
| Beauty Hair Products Limited | Wholesale & retail | 1988 |
| Beck ROW (Suffolk) Management Company Limited | Households | 2023 |
| Becket's Court Management Company Limited | Households | 2001 |