| Austin Trueman Holdings Limited | Professional & scientific | 1989 |
| Authentic Therapy & Training Limited | Health & social care | 2023 |
| Auto ARC Limited | Wholesale & retail | 2024 |
| Auto Body Rescue Ltd | Wholesale & retail | 2021 |
| Auto Dealerz Ltd | Wholesale & retail | 2025 |
| Auto Q Ltd | Wholesale & retail | 2025 |
| Autocure Repairs and Diagnostics Ltd | Wholesale & retail | 2019 |
| Autodonor Ltd | Wholesale & retail | 2014 |
| Automeds Aylesbury Ltd | Wholesale & retail | 2023 |
| Automotive Paint Refinishing Solutions Limited | Wholesale & retail | 2021 |
| Autosport UK Ltd | Wholesale & retail | 2006 |
| Autosrepair Ltd | Wholesale & retail | 2025 |
| Autozonesmart UK Ltd | Wholesale & retail | 2018 |
| Autumn Holdings Ltd | Real estate | 2025 |
| Avance Projects Ltd | Information & communication | 2025 |
| Avant-Garde Interiors Limited | Construction | 2012 |
| Avanti Salon Limited | Other services | 2013 |
| AVE Maria Limited | Health & social care | 2014 |
| Avego Limited | Wholesale & retail | 2024 |
| Avenna THF Ltd | Health & social care | 2017 |
| Aventuro Brands Ltd | Wholesale & retail | 2025 |
| Aventus Design Ltd | Professional & scientific | 2003 |
| Averoworks Limited | Information & communication | 2026 |
| Averroes One Limited | Wholesale & retail | 2021 |
| Avery IT Consultancy Limited | Information & communication | 2017 |
| Avidity Science Limited | Professional & scientific | 1997 |
| Avighna Technology Limited | Administrative & support | 2016 |
| Avocet Event Management Ltd | Administrative & support | 2014 |
| Avon 1968 Limited | Extraterritorial | 2014 |
| Avonbeg Construction Ltd | Professional & scientific | 2011 |
| Avonbridge Limited | Professional & scientific | 2018 |
| AVR Carpets and Flooring Ltd | Construction | 2026 |
| Avrs Consultancy Ltd | Professional & scientific | 2010 |
| AVS Added Value Solutions UK, Ltd | Professional & scientific | 2014 |
| Avviq Consulting Limited | Professional & scientific | 2019 |
| AW IT Support Limited | Information & communication | 2013 |
| Awakening Therapy and Development Services Ltd | Health & social care | 2023 |
| Awan Enterprise Ltd | Real estate | 2017 |
| Away and Home UK Ltd | Wholesale & retail | 2022 |
| AWC Design Ltd | Information & communication | 2025 |
| Awkwardly Social Limited | Professional & scientific | 2025 |
| AWM Healthcare Limited | Health & social care | 2022 |
| Awta Homes Ltd | Real estate | 2023 |
| AWW Services Limited | Administrative & support | 2016 |
| Axatax Pest Control Limited | Professional & scientific | 2010 |
| Axial Vision Solutions Ltd | Information & communication | 2013 |
| Axle Media Limited | Professional & scientific | 2025 |
| AXS Heating Limited | Construction | 2024 |
| AYA Fashion Ltd | Wholesale & retail | 2024 |
| Ayan Grill Ltd | Hospitality | 2024 |
| Ayeina Ltd | Wholesale & retail | 2025 |
| Aylesbury Accountancy Limited | Extraterritorial | 2019 |
| Aylesbury Accountants Ltd | Professional & scientific | 2016 |
| Aylesbury Advance Auto Ltd | Wholesale & retail | 2025 |
| Aylesbury Adventure Golf Ltd. | Arts & recreation | 2019 |
| Aylesbury African Cash & Carry Limited | Wholesale & retail | 2021 |
| Aylesbury Air Conditioning Limited | Energy | 2002 |
| Aylesbury Bathroom Centre Ltd | Wholesale & retail | 2019 |
| Aylesbury BBQ and Events Ltd | Hospitality | 2024 |
| Aylesbury BED and Furniture Centre Limited | Households | 2017 |
| Aylesbury Box Company Limited | Manufacturing | 1986 |
| Aylesbury Buckinghamshire Plumbing and Heating Ltd | Construction | 2023 |
| Aylesbury Building Services Limited | Construction | 2005 |
| Aylesbury Canal Society Limited | Arts & recreation | 2009 |
| Aylesbury Chicken Limited | Hospitality | 2024 |
| Aylesbury Connect Ltd | Transport & logistics | 2024 |
| Aylesbury Counselling Ltd | Health & social care | 2014 |
| Aylesbury Dairy Ltd | Wholesale & retail | 2020 |
| Aylesbury Drum School Ltd | Education | 2024 |
| Aylesbury Drycleaners Ltd | Other services | 2016 |
| Aylesbury Electrical Services Limited | Construction | 1977 |
| Aylesbury Express Freight Limited | Transport & logistics | 2016 |
| Aylesbury Exterior Cleaning Limited | Administrative & support | 2025 |
| Aylesbury Fast Food Ltd | Hospitality | 2025 |
| Aylesbury Fencing Limited | Administrative & support | 2003 |
| Aylesbury Flooring Limited | Wholesale & retail | 1990 |
| Aylesbury Foods Ltd | Hospitality | 2024 |
| Aylesbury Football Academy Ltd | Arts & recreation | 2023 |
| Aylesbury Fusion Ltd | Hospitality | 2025 |
| Aylesbury Gadget Exchange Limited | Wholesale & retail | 2020 |
| Aylesbury Gadgets Limited | Wholesale & retail | 2025 |
| Aylesbury Gardening Ltd | Administrative & support | 2021 |
| Aylesbury Gates Ltd | Extraterritorial | 2018 |
| Aylesbury Glazing Repairs Ltd | Other services | 2016 |
| Aylesbury Golf Centre Limited | Arts & recreation | 1990 |
| Aylesbury Grammar School | Education | 2011 |
| Aylesbury Granulation Services Ltd | Water & waste | 2014 |
| Aylesbury Gymnastics Academy (AGA) | Arts & recreation | 2008 |
| Aylesbury Health and Wellness Limited | Health & social care | 2025 |
| Aylesbury High School | Education | 2011 |
| Aylesbury Lawyers Ltd | Professional & scientific | 2022 |
| Aylesbury Masonic Hall,Limited | Other services | 1947 |
| Aylesbury Mobile Car Wash Ltd | Administrative & support | 2025 |
| Aylesbury MOT Centre Limited | Wholesale & retail | 2000 |
| Aylesbury Motor Group Ltd | Wholesale & retail | 2021 |
| Aylesbury Motors Ltd | Wholesale & retail | 2017 |
| Aylesbury Performance Centre Limited | Wholesale & retail | 2015 |
| Aylesbury Pizza Ltd | Hospitality | 2024 |
| Aylesbury Plant Hire Ltd | Administrative & support | 2012 |
| Aylesbury Property Group Ltd | Real estate | 2023 |