| Autoreel Limited | Manufacturing | 1985 |
| Autorooms Group Holdings Limited | Financial services | 2026 |
| Autorooms Ltd | Professional & scientific | 2024 |
| Autos and Services Limited | Other services | 2019 |
| Autos Clinic Ltd | Wholesale & retail | 2025 |
| Autosave (Nottingham) Ltd | Wholesale & retail | 2023 |
| Autosave Motorist Centre Ltd | Wholesale & retail | 2023 |
| Autosave Motorist Discount Limited | Wholesale & retail | 1977 |
| Autoteam UK Limited | Wholesale & retail | 2026 |
| Autotech Cars Ltd | Wholesale & retail | 2019 |
| Autowave Group Limited | Financial services | 2021 |
| Autowave Holdings Limited | Real estate | 2020 |
| Autowave Limited | Wholesale & retail | 2013 |
| Autowave Trading Limited | Wholesale & retail | 2016 |
| Autriva Ltd | Information & communication | 2025 |
| Auxano Ltd | Information & communication | 2019 |
| Auxo Holdings Ltd | Financial services | 2021 |
| AV 4 Home Ltd | Professional & scientific | 2007 |
| AV Cleaners Ltd | Construction | 2023 |
| AV Conference Events Ltd | Administrative & support | 2024 |
| AV Properties 1 Limited | Real estate | 2022 |
| AV Tomson Holdings Ltd | Financial services | 2024 |
| AVA Acquisitions Ltd | Real estate | 2021 |
| AVA Network Services Ltd | Information & communication | 2021 |
| AVA Tech Electrical Services Limited | Construction | 2019 |
| AVA Wealth Ltd | Financial services | 2024 |
| Avacado Ltd | Real estate | 2020 |
| Avag Limited | Financial services | 2021 |
| Avail Collective Ltd | Information & communication | 2022 |
| Avail Group UK Limited | Wholesale & retail | 2018 |
| Available Storage Ltd | Transport & logistics | 2004 |
| Availiant Solutions Limited | Professional & scientific | 2006 |
| Avalon London Projects Ltd | Construction | 2025 |
| Avam Cuts Ltd | Other services | 2025 |
| Avant Data Ltd | Construction | 2022 |
| Avant Design Services Ltd | Professional & scientific | 2022 |
| Avanta Plumbing and Heating Limited | Construction | 2015 |
| Avanti Eco Homes Ltd | Construction | 2024 |
| Avanti Homecare (Holdings) Limited | Financial services | 2020 |
| Avanti Homecare (Ripley) Limited | Health & social care | 2020 |
| Avanti Homecare (Training) Limited | Health & social care | 2020 |
| Avanti Homecare Limited | Health & social care | 2018 |
| Avanti Print Limited | Manufacturing | 2012 |
| Avanti Solar Homes Limited | Construction | 2018 |
| AVB Group Limited | Wholesale & retail | 2026 |
| AVB Logistics Limited | Transport & logistics | 2024 |
| Avec Topco Limited | Professional & scientific | 2017 |
| Avenca Environmental Services Limited | Professional & scientific | 2021 |
| Avenex Consultancy Group Ltd | Information & communication | 2026 |
| Avenue C Ltd | Professional & scientific | 2023 |
| Avenue Hotel (Grantham) Limited | Hospitality | 2006 |
| AVENUE29 Limited | Information & communication | 2017 |
| Avenuepoint Limited | Construction | 2005 |
| AVENUES2WORK Ltd | Education | 2018 |
| Avenya Ltd | Wholesale & retail | 2026 |
| Averill Land Limited | Agriculture & fishing | 1999 |
| Averlon Global (UK) Ltd | Professional & scientific | 2024 |
| Avero Capital Ltd | Real estate | 2025 |
| Avero Projects Ltd | Construction | 2025 |
| Averroes Acquisition Ltd | Real estate | 2021 |
| Avery Dennison Retail Information Services UK Limited | Manufacturing | 1984 |
| Avery's Childminding Ltd | Health & social care | 2025 |
| Avery-Crofts Management Company Limited | Construction | 2024 |
| Aves Mantra Ltd | Transport & logistics | 2022 |
| Avgorou 2 Limited | Administrative & support | 2024 |
| AVH Eco Services Limited | Construction | 2013 |
| AVI Hospitality Ltd | Hospitality | 2024 |
| Avianorth Aviation Consulting Ltd | Education | 2023 |
| Aviation Economics Limited | Professional & scientific | 1994 |
| Aviator Tech Limited | Wholesale & retail | 2024 |
| Avica HR Limited | Professional & scientific | 2019 |
| Avicenna Sanatio LLP | | 2012 |
| Avid IT Consulting Limited | Information & communication | 2023 |
| Avidacare Ltd | Financial services | 2025 |
| Avira Constructions Ltd | Construction | 2024 |
| AVL Business Advisory Limited | Professional & scientific | 2013 |
| AVO Invents Limited | Professional & scientific | 2015 |
| Avois Ltd | Professional & scientific | 2025 |
| Avon Ridge Properties Ltd | Construction | 2022 |
| Avondale Advisory Limited | Professional & scientific | 2019 |
| Avonfray Limited | Administrative & support | 2025 |
| Avontrent Limited | Information & communication | 2013 |
| Avontrent Property Limited | Real estate | 2017 |
| AVS Joinery Limited | Construction | 2026 |
| AVS Total Security Ltd | Administrative & support | 2022 |
| AVT & Partners Ltd | Financial services | 2024 |
| Avtala Consulting Ltd | Professional & scientific | 2023 |
| Avtech Services Limited | Information & communication | 2011 |
| Avuno Ltd | Wholesale & retail | 2026 |
| Avvia Ltd | Professional & scientific | 2014 |
| AW & TB Holdings Ltd | Financial services | 2025 |
| AW & UA Holdings Ltd | Financial services | 2025 |
| AW Agri Limited | Agriculture & fishing | 2026 |
| AW Brickwork and Building Services Ltd | Construction | 2024 |
| AW Code Solutions Ltd | Information & communication | 2025 |
| AW Motor Group Ltd | Wholesale & retail | 2024 |
| AW Plumbing Ltd | Construction | 2018 |
| AW Property International Limited | Real estate | 2011 |
| AW Residential Limited | Real estate | 2021 |
| AW Summit Holdings Ltd | Financial services | 2026 |