| Auto Enhancements Limited | Wholesale & retail | 2025 |
| Auto Express Centre Limited | Wholesale & retail | 2017 |
| Auto German Specialists Ltd | Wholesale & retail | 2020 |
| Auto Keys Derby Ltd | Wholesale & retail | 2024 |
| Auto Locksmith Express Limited | Wholesale & retail | 2023 |
| Auto Merchant Ltd | Wholesale & retail | 2021 |
| Auto Pass Derby Ltd | Education | 2025 |
| Auto Tradesman 1 Ltd | Wholesale & retail | 2024 |
| Auto Tradesman Ltd | Wholesale & retail | 2020 |
| Auto-Tech Diagnostics Ltd | Wholesale & retail | 2024 |
| Autogyn Ltd | Manufacturing | 2019 |
| Autokraft (UK) Limited | Professional & scientific | 2008 |
| Autoles Ltd | Construction | 2016 |
| Autolux Tinting Solutions Ltd | Wholesale & retail | 2023 |
| Automation Products Limited | Wholesale & retail | 2009 |
| Automech (Midlands) Ltd | Wholesale & retail | 2011 |
| Automotion Cars Limited | Wholesale & retail | 2012 |
| Autonext Ltd | Wholesale & retail | 2015 |
| Autonomy Healthcare Limited | Health & social care | 2011 |
| Autonomy Innovations Limited | Health & social care | 2026 |
| Autonomy Securities Limited | Health & social care | 2011 |
| AUTOROOMS34 Ltd | Wholesale & retail | 2020 |
| Autosense Derby Ltd | Wholesale & retail | 2024 |
| Autotech Installations Ltd | Wholesale & retail | 2021 |
| Autotechz (UK) Limited | Wholesale & retail | 2012 |
| Autumn Residential Care Limited | Health & social care | 2025 |
| AUX Group Limited | Financial services | 2020 |
| Auxilium Partnership Limited | Financial services | 2018 |
| AV Palace Limited | Real estate | 2026 |
| AV Resilience Ltd | Wholesale & retail | 2010 |
| AVA Consultants International Ltd. | Professional & scientific | 2016 |
| AVA Solutions Training & Consultancy Ltd | Professional & scientific | 2021 |
| Available Car Limited | Wholesale & retail | 2001 |
| Available Properties Limited | Construction | 2007 |
| Available Vehicles Limited | Extraterritorial | 2000 |
| Avance Clinic Limited | Extraterritorial | 2019 |
| Avant Recovery Services Ltd | Transport & logistics | 2021 |
| Avant-Gardesign Limited | Manufacturing | 2012 |
| Avantgarde Digital Limited | Information & communication | 2015 |
| Avanti IT Services Limited | Information & communication | 2012 |
| Avasmile MIX Ltd | Transport & logistics | 2024 |
| AVATAR261 Limited | Information & communication | 2014 |
| AVC Living Holdings Ltd | Financial services | 2025 |
| AVC Living Ltd | Real estate | 2025 |
| Avengers Properties Limited | Real estate | 2022 |
| Avenue Construction Ltd | Construction | 2023 |
| Avenue Gardens Management Company Limited | Households | 2007 |
| Avenue Impact Development CIC | Health & social care | 2023 |
| Avenue Impact Limited | Information & communication | 2015 |
| Avenza by Driving Experts Ltd | Education | 2026 |
| Avero Health Ltd | Health & social care | 2025 |
| Avicenna Health Group Ltd | Financial services | 2025 |
| Avicenna’S Apothecary Ltd | Manufacturing | 2023 |
| Avigail Residence Limited | Real estate | 2023 |
| Avnai Properties Ltd | Real estate | 2024 |
| AVS Decorators Limited | Construction | 2023 |
| AVS15 Limited | Other services | 2026 |
| Avsmith Limited | Health & social care | 2013 |
| AVT Windows Ltd | Construction | 2023 |
| Avykax Ltd | Information & communication | 2026 |
| AW & Sons Developments Ltd | Construction | 2019 |
| AW Consultants Limited | Professional & scientific | 2023 |
| AW Derby Properties Limited | Real estate | 2020 |
| AW Midlands Limited | Information & communication | 2020 |
| Awac Land Investment Ltd | Real estate | 2021 |
| Awac Property Investment Ltd | Real estate | 2020 |
| Awami Group Ltd | Financial services | 2023 |
| Awami Travel Ltd | Transport & logistics | 2022 |
| Awba Ltd | Real estate | 2026 |
| AWD Development Solutions Ltd | Professional & scientific | 2014 |
| AWG Holdings Ltd | Construction | 2025 |
| Awillis Rail Limited | Manufacturing | 2023 |
| Awlaad Estates Limited | Real estate | 2026 |
| Awnr Ltd | Real estate | 2020 |
| AWP Plumbing & Heating Ltd | Construction | 2015 |
| Awpm Solutions Limited | Professional & scientific | 2019 |
| AWR (UK) Limited | Information & communication | 2011 |
| AWR Accountants & Business Advisors LLP | | 2010 |
| AWR Accountants Ltd | Professional & scientific | 2014 |
| AWR Engineering (UK) Ltd | Manufacturing | 2014 |
| AWR Estate Management Ltd | Real estate | 2017 |
| AWR Group Ltd | Financial services | 2021 |
| AWR Housing Ltd | Real estate | 2025 |
| AWR Property Holding Ltd | Real estate | 2021 |
| AWR Surgical Instruments Ltd | Administrative & support | 2016 |
| AWS Bidco Limited | Water & waste | 2020 |
| AWS Consult Ltd | Professional & scientific | 2026 |
| AWS Finco Limited | Water & waste | 2020 |
| AWS Maans UK Ltd | Wholesale & retail | 2020 |
| AWS Midco Limited | Water & waste | 2020 |
| AWS Topco Limited | Water & waste | 2020 |
| AX11 Enterprises Ltd | Wholesale & retail | 2024 |
| Axec Consulting Ltd | Professional & scientific | 2024 |
| Axiom Consultancy Services Ltd | Information & communication | 2025 |
| Axiom Supported Living Limited | Health & social care | 2018 |
| Axion IT Services Limited | Administrative & support | 2012 |
| Axis Accounting & Consulting Limited | Professional & scientific | 2026 |
| Axisnova Ltd | Information & communication | 2026 |
| AXN Building & Roofing LLP | | 2026 |
| Axxiom Digital Limited | Information & communication | 2021 |