| Automotrade Ltd | Extraterritorial | 2023 |
| Automove Logistics Ltd | Transport & logistics | 2025 |
| Autonaire Limited | Information & communication | 2025 |
| Autono-Med Limited | Wholesale & retail | 1997 |
| Autonomy Motor Sports Club Limited | Health & social care | 2009 |
| Autopfect Holdings Limited | Financial services | 2026 |
| Autopoint Guiseley Ltd | Wholesale & retail | 2023 |
| Autopsy Cover Limited | Health & social care | 2019 |
| Autorotation Technology Ltd | Information & communication | 2017 |
| Autosave (Yeadon) Limited | Wholesale & retail | 2026 |
| Autoshift Transport Ltd | Transport & logistics | 2026 |
| Autospeed Limited | Wholesale & retail | 2018 |
| Autostrade Limited | Wholesale & retail | 2025 |
| Autostrasse Limited | Wholesale & retail | 1997 |
| Autotopia Ltd | Wholesale & retail | 2023 |
| Autovitalia Ltd | Wholesale & retail | 2025 |
| Autovivendi Group Limited | Administrative & support | 2025 |
| Autowide Ltd | Information & communication | 2018 |
| Autrax Limited | Wholesale & retail | 2025 |
| Autumn and MAY Jewellery Designs Ltd | Wholesale & retail | 2016 |
| Autumn and MAY Toiletries Limited | Extraterritorial | 2001 |
| Autumn HR Consulting Ltd | Administrative & support | 2020 |
| Auty Square Management Company Limited | Households | 2015 |
| Auxerre Platforms Holding Limited | Professional & scientific | 2024 |
| Auxesis Ltd | Real estate | 2020 |
| Auxetec Limited | Professional & scientific | 2020 |
| Auxth Limited | Information & communication | 2022 |
| AV Care Services Limited | Health & social care | 2013 |
| AV Specialist Services Ltd | Health & social care | 2024 |
| AV Support 247 Limited | Administrative & support | 2022 |
| AVA Healthcare Ltd | Hospitality | 2020 |
| AVA Logistic Ltd | Wholesale & retail | 2023 |
| Avadanei Ltd | Transport & logistics | 2025 |
| Avadanei Removals Ltd | Transport & logistics | 2025 |
| Avagrace Couture Limited | Wholesale & retail | 2014 |
| Avahope Limited | Financial services | 2025 |
| Avalon Benefits Limited | Administrative & support | 2025 |
| Avalon Media Services Limited | Professional & scientific | 2000 |
| Avalon Strategies Limited | Administrative & support | 2025 |
| Avalon Tailoring Ltd | Other services | 2012 |
| Avalon Tech Ltd | Information & communication | 2025 |
| Avam Events Ltd | Administrative & support | 2024 |
| Avana Group Ltd | Wholesale & retail | 2018 |
| Avana Property Group Ltd | Real estate | 2025 |
| Avannaata Properties Ltd | Real estate | 2024 |
| Avant Bustle Limited | Information & communication | 2025 |
| Avant Coatings Limited | Construction | 2005 |
| Avant Garden Solutions Limited | Administrative & support | 2024 |
| Avant-Tout (Management Services) Limited | Professional & scientific | 2012 |
| Avanta Care Ltd | Administrative & support | 2012 |
| Avanta Care Perm Limited | Administrative & support | 2019 |
| Avanta Holdings Ltd | Wholesale & retail | 2017 |
| Avanta UK Holdings Limited | Financial services | 2021 |
| Avanta UK Limited | Construction | 2000 |
| Avantgarde CTS Limited | Health & social care | 2024 |
| Avanti Accounting Solutions Limited | Professional & scientific | 2020 |
| Avanti Imports Limited | Wholesale & retail | 2018 |
| Avantifix Ltd | Wholesale & retail | 2019 |
| Avantifix Properties Limited | Real estate | 2000 |
| Avantis Integrated Services Ltd | Professional & scientific | 2026 |
| Avantra Services Ltd | Professional & scientific | 2023 |
| Avanza Associates Ltd | Other services | 2017 |
| Avarian Limited | Real estate | 2020 |
| Avart Ltd | Transport & logistics | 2017 |
| Avba Homes Limited | Real estate | 2020 |
| AVC Camper Conversions Ltd | Wholesale & retail | 2024 |
| AVC Consult Ltd | Other services | 2025 |
| AVC Study Education Ltd | Education | 2024 |
| Avencia Group Limited | Administrative & support | 2025 |
| Avenfield Property Management Ltd | Real estate | 2024 |
| Avenida Properties Ltd | Real estate | 2024 |
| Avenite Ltd | Manufacturing | 2024 |
| Aventia Ltd | Wholesale & retail | 2023 |
| Aventra IT Technologies Ltd | Information & communication | 2025 |
| Aventurine House Ltd | Health & social care | 2022 |
| Aventus Fire Systems Ltd | Construction | 2018 |
| Avenue Properties Limited | Construction | 2009 |
| AVENUE3 Limited | Information & communication | 2020 |
| Avenza Trading UK Ltd | Wholesale & retail | 2026 |
| Average to Medium Chat Ltd | Wholesale & retail | 2026 |
| Averagedream Limited | Wholesale & retail | 2014 |
| Averit Ltd | Extraterritorial | 2019 |
| Averleigh & Sons Ltd | Wholesale & retail | 2026 |
| Averroes Constructions Limited | Construction | 2020 |
| Avery and Walters Limited | Professional & scientific | 2012 |
| Avery Fairbank Limited | Administrative & support | 2021 |
| Avery Fairbank London Ltd | Administrative & support | 2026 |
| Avetix Group Ltd | Administrative & support | 2022 |
| Avey Ltd | Public administration | 2026 |
| Avi's Hand Car Wash Ltd | Other services | 2021 |
| Avia Group Limited | Construction | 2016 |
| Aviation Consultants Ltd | Other services | 2021 |
| Avid Bidco Limited | Financial services | 2019 |
| Avid Insurance Services Limited | Financial services | 2003 |
| Avid Midco Limited | Financial services | 2019 |
| Avid Technologies Limited | Information & communication | 2015 |
| Avid Topco Limited | Financial services | 2019 |
| Avie Consulting Limited | Construction | 2012 |
| Avie Holdings 25 Limited | Construction | 2025 |
| Avie Holdings Ltd | Construction | 2019 |