| Automation Consultants Limited | Information & communication | 2000 |
| Automotive Talent Partners Ltd | Administrative & support | 2025 |
| Automotive UK Limited | Professional & scientific | 2002 |
| Autonomy Systems Limited | Information & communication | 1995 |
| Autopixel 360 Ltd | Information & communication | 2026 |
| Autos Assist Ltd | Other services | 2018 |
| Autosigns & Graphics Ltd | Professional & scientific | 2022 |
| Autovibe Solutions Ltd | Transport & logistics | 2024 |
| AV Cleaning Solutions Ltd | Administrative & support | 2025 |
| AV Semantic Limited | Information & communication | 2013 |
| Av-It Strategy Consultancy Ltd | Information & communication | 2013 |
| AV8ION Global Limited | Administrative & support | 2018 |
| AVA Drive Ltd | Wholesale & retail | 2026 |
| AVA Gold Ltd | Wholesale & retail | 2026 |
| AVA IT Consultants Limited | Information & communication | 2009 |
| AVA Property Ltd | Real estate | 2026 |
| Avaa Properties Limited | Real estate | 2018 |
| Avaa Retail Limited | Wholesale & retail | 2026 |
| Avaan Properties Limited | Real estate | 2023 |
| Avada Collectibles Ltd | Wholesale & retail | 2023 |
| Availability Consulting Limited | Information & communication | 2010 |
| Avala Partners Ltd | Information & communication | 2025 |
| Avalon Information Services Ltd | Information & communication | 2017 |
| Avalon Residents Management Company Limited | Households | 2005 |
| Avaltec Limited | Other services | 2011 |
| Avan Motors Ltd | Wholesale & retail | 2020 |
| Avantgarde Consulting (UK) Limited | Information & communication | 2009 |
| Avanti Cycling Ltd | Education | 2014 |
| Avanti Cycling Trust CIC | Arts & recreation | 2018 |
| Avanti Recruitment Ltd | Administrative & support | 2009 |
| Avantica Houses Ltd | Real estate | 2020 |
| Avantus Business Solutions Limited | Financial services | 2005 |
| Avantus Employee Benefits Limited | Information & communication | 2003 |
| Avantus HR Limited | Information & communication | 2014 |
| Avantus Limited | Information & communication | 2017 |
| Avantus People Solutions Limited | Information & communication | 2017 |
| Avantus Resources Limited | Information & communication | 2014 |
| Avantus Systems Limited | Information & communication | 2013 |
| Avantus Technology Limited | Extraterritorial | 2014 |
| Avat Ltd | Administrative & support | 2002 |
| Avatar Accounting & Taxation Ltd | Extraterritorial | 2018 |
| Avatid Limited | Information & communication | 2025 |
| AVD Computer Services Limited | Wholesale & retail | 2000 |
| Avec SKI Limited | Wholesale & retail | 2024 |
| Aveillant Limited | Manufacturing | 2011 |
| Avenell Project Management Limited | Administrative & support | 2015 |
| Aventis Pharma Holdings Limited | Financial services | 1999 |
| Aventis Pharma Limited | Wholesale & retail | 1980 |
| Avents Paddock Ltd | Construction | 2026 |
| Avenue Autobody Limited | Wholesale & retail | 2003 |
| Avenue Court (Tadworth) Management Company Limited | Households | 1989 |
| Averbrian Investments,Limited | Real estate | 1937 |
| Avery Clifton Limited | Administrative & support | 2014 |
| AVI Transport and Logistics Limited | Transport & logistics | 2026 |
| Avian Infotech Ltd | Information & communication | 2010 |
| Aviate Pro Limited | Professional & scientific | 2017 |
| Aviation Sales Limited | Wholesale & retail | 2018 |
| Aviation, Advice and Consulting Limited | Transport & logistics | 2010 |
| Avilah Foods Limited | Hospitality | 2015 |
| Avimo Middle East Limited | Professional & scientific | 1969 |
| Avimo Pension Trustees Limited | Extraterritorial | 2011 |
| Avinaya Technologies Limited | Information & communication | 2024 |
| Aviscanary Ltd | Information & communication | 2025 |
| Avish Technologies Ltd | Information & communication | 2024 |
| Aviskaar Enterprises Ltd | Information & communication | 2015 |
| Avista Corporate Services UK Limited | Professional & scientific | 2017 |
| AVJ Repair Ltd | Wholesale & retail | 2020 |
| AVK Consulting Services Limited | Information & communication | 2010 |
| AVK Innovations Ltd | Information & communication | 2017 |
| AVL Furniture Ltd | Manufacturing | 2020 |
| Avni Consultancy Services Limited | Information & communication | 2024 |
| Avni Medical Limited | Health & social care | 2022 |
| Avni Properties Limited | Real estate | 2019 |
| Avocet Energy LLP | | 2023 |
| Avolaunch Technologies Ltd | Information & communication | 2023 |
| Avon Asset Holdings Ltd | Real estate | 2018 |
| Avondale Foot Care & Beauty Ltd | Other services | 2023 |
| AVR Global Ltd | Real estate | 2025 |
| AVR International Limited | Information & communication | 2004 |
| AVR Technologies Ltd | Information & communication | 2016 |
| Avro Health Ltd | Wholesale & retail | 2023 |
| AVS Developments Limited | Real estate | 2024 |
| AVS Info Ltd | Information & communication | 2026 |
| AVS Info Systems Limited | Information & communication | 2017 |
| Avsar Investments Limited | Real estate | 2021 |
| Avvale Ltd | Professional & scientific | 2023 |
| Avyay Consulting Services Limited | Information & communication | 2017 |
| Avyor Ltd | Water & waste | 2024 |
| AW Cleaning Services Limited | Administrative & support | 2025 |
| AW Design and Development Limited | Professional & scientific | 2018 |
| AWA Financial Solutions Limited | Financial services | 2004 |
| AWA London Ltd | Wholesale & retail | 2021 |
| Awah Services Limited | Other services | 2015 |
| Award Recruitment Ltd | Administrative & support | 2014 |
| Awardaroo! Ltd | Information & communication | 2005 |
| Awarded Customer Relationship Management Technologies Limited | Information & communication | 2011 |
| Awaters Limited | Extraterritorial | 2023 |
| Awaylise Limited | Hospitality | 2021 |
| Aways on Time Limited | Transport & logistics | 2019 |
| AWB TEK Ltd | Information & communication | 2014 |