| Adam Wareham Actuarial Consulting Limited | Financial services | 2010 |
| Adamas Consult Ltd | Professional & scientific | 2025 |
| Adasr Solutions Limited | Information & communication | 2024 |
| Addison LEE Enterprises PVT Ltd | Administrative & support | 2025 |
| Addo Play Limited | Professional & scientific | 2015 |
| Adept Building Services Limited | Construction | 1996 |
| Adimpra Consulting Limited | Information & communication | 2022 |
| Aditya Services Ltd | Wholesale & retail | 2008 |
| Advance Driver Management Ltd | Arts & recreation | 2022 |
| Advanced New Media Group Ltd | Information & communication | 2026 |
| AF Fitness Group Ltd | Administrative & support | 2023 |
| AG Developers Limited | Construction | 2026 |
| AG Internet Services Limited | Real estate | 2013 |
| AG IT Consultancy Limited | Information & communication | 2017 |
| Agam Associates Limited | Real estate | 2021 |
| Agastya Consulting Limited | Financial services | 2023 |
| Agencytech Ltd | Manufacturing | 2025 |
| Agility Financial Solutions Ltd | Administrative & support | 2009 |
| Agincourt Partners Ltd | Information & communication | 2015 |
| Agmaw Consulting Ltd | Professional & scientific | 2025 |
| Ah.Denner Consultancy Ltd | Professional & scientific | 2026 |
| AHA Cafe Ltd | Hospitality | 2017 |
| Ahpl Consultants Limited | Information & communication | 2015 |
| AIB Medical Services Ltd | Health & social care | 2017 |
| AIM High Consultancy Limited | Professional & scientific | 2022 |
| AJD Housing Ltd | Real estate | 2020 |
| AJF Ltd | Information & communication | 2014 |
| AK Lincoln Ltd | Wholesale & retail | 2023 |
| AK Liverpool Limited | Wholesale & retail | 2018 |
| AK Stunt Production Limited | Information & communication | 2023 |
| AKG Consulting Limited | Information & communication | 2009 |
| Akkuvi Limited | Real estate | 2025 |
| AKM Holding Limited | Real estate | 2018 |
| Akms Properties Limited | Real estate | 2023 |
| Akms Retail Limited | Wholesale & retail | 2023 |
| Akosoft Ltd | Information & communication | 2014 |
| Akshara Estates Ltd | Real estate | 2020 |
| Akshoman Investments Ltd | Real estate | 2024 |
| AL52 Ltd | Real estate | 2020 |
| Alcara Enterprises Ltd | Arts & recreation | 2010 |
| Alco Glass Systems Limited | Manufacturing | 1998 |
| Alexander Grace Homes (Land Assets) Ltd | Administrative & support | 2010 |
| Alexander Jones International Limited | Administrative & support | 2009 |
| ALI Hearn Interiors Ltd | Wholesale & retail | 2012 |
| ALL County Driveways Ltd | Construction | 2025 |
| ALL My Needs UK Ltd | Wholesale & retail | 2019 |
| ALL on the Wall Ltd | Wholesale & retail | 2020 |
| Allday Smith Design Ltd | Information & communication | 2014 |
| Alloura Limited | Professional & scientific | 2017 |
| Allpoints Executive Hire Ltd | Transport & logistics | 2019 |
| Allsoptv Ltd | Information & communication | 2023 |
| Allt Power Limited | Agriculture & fishing | 2009 |
| ALM Renovations Ltd | Extraterritorial | 2023 |
| Alpha Capital Projects Limited | Construction | 1997 |
| Alphabase Investments Limited | Construction | 1979 |
| Alpi Limited | Professional & scientific | 2001 |
| ALT Edit Limited | Information & communication | 2013 |
| ALT Perspective Consulting Ltd | Professional & scientific | 2025 |
| Altanis Global Limited | Wholesale & retail | 2026 |
| Alteva Advisory Ltd | Information & communication | 2026 |
| Altitude Startups Ltd | Information & communication | 2022 |
| Altonpride Limited | Construction | 1989 |
| Aman Technologies Limited | Information & communication | 2013 |
| Amaya Spa (Amersham) Ltd | Other services | 2019 |
| Amaze Film Services Ltd | Professional & scientific | 2021 |
| Amberley Design Limited | Professional & scientific | 2025 |
| Amberley Innovations Limited | Information & communication | 2020 |
| Amberson Property Investment Co. Limited | Real estate | 1999 |
| Amberstand Limited | Other services | 2026 |
| Ambrit Consulting Limited | Information & communication | 2013 |
| AMC Logistics Limited | Professional & scientific | 2002 |
| AMD Sales & Marketing Ltd | Professional & scientific | 2022 |
| Amdox Property Ltd | Real estate | 2025 |
| Amersham Accountancy Limited | Professional & scientific | 2013 |
| Amersham Chiropractic Clinic Limited | Health & social care | 2008 |
| Amersham Coaching Ltd | Arts & recreation | 2021 |
| Amersham Commercial Park Limited | Administrative & support | 2011 |
| Amersham Court (Commercial) Limited | Extraterritorial | 2017 |
| Amersham Court Limited | Extraterritorial | 2017 |
| Amersham Cricket Club Limited | Arts & recreation | 2020 |
| Amersham Cricket Club Members Limited | Arts & recreation | 2020 |
| Amersham Gardening Ltd | Arts & recreation | 2020 |
| Amersham Health & Fitness Limited | Arts & recreation | 2017 |
| Amersham International Motors Limited | Wholesale & retail | 2026 |
| Amersham Logistics Ltd | Transport & logistics | 2024 |
| Amersham Mangal Ltd | Hospitality | 2018 |
| Amersham MOT Station Limited | Wholesale & retail | 2018 |
| Amersham Motor Works Ltd | Wholesale & retail | 2025 |
| Amersham Multi Trade Centre Ltd | Wholesale & retail | 2023 |
| Amersham Museum Limited | Arts & recreation | 1984 |
| Amersham Physios Ltd | Other services | 2021 |
| Amersham Prestige Limited | Wholesale & retail | 2020 |
| Amersham Restaurants Limited | Hospitality | 2023 |
| Amersham School | Education | 2011 |
| Amersham Vehicle Hire Ltd | Administrative & support | 2025 |
| Amersham Wine Club Ltd | Wholesale & retail | 2025 |
| Amersham Wine Merchants Ltd | Wholesale & retail | 2025 |
| Amerstone Ltd | Real estate | 2019 |
| Amim NO 1 LP | | 2011 |
| Amlets Park Limited | Real estate | 2012 |