| Alderson House Events Limited | Hospitality | 2026 |
| Alex International Solutions Ltd | Other services | 2012 |
| Alex Selby Health & Fitness Ltd | Arts & recreation | 2018 |
| Alexander Pittaway Ltd | Professional & scientific | 2013 |
| Alfie Fish & Chips Limited | Hospitality | 2022 |
| Alice Cargo Service Ltd | Extraterritorial | 2024 |
| Alisgp Trading Co., Ltd | Wholesale & retail | 2021 |
| Alison Johnson Artist Limited | Arts & recreation | 2021 |
| Alita Import and Export Co., Ltd | Administrative & support | 2019 |
| ALL - Round Gifts Co., Limited | Wholesale & retail | 2023 |
| ALL Equipment Finance Ltd | Financial services | 2021 |
| ALL for One Digital Ltd | Information & communication | 2024 |
| Allema International Limited | Other services | 2016 |
| Allesley Holdings Limited | Financial services | 2024 |
| Alliance Wire Forming Tech Co., Ltd | Administrative & support | 2019 |
| Allstar Industry Ltd | Wholesale & retail | 2019 |
| Allworks Construction Limited | Construction | 2006 |
| Almarose Limited | Hospitality | 2019 |
| Alnialam Limited | Financial services | 2013 |
| Alon Properties Limited | Real estate | 2021 |
| Alpha Offshore Limited | Administrative & support | 2023 |
| Alpha Prospects Limited | Administrative & support | 2006 |
| Alphatech Engineering Products Limited | Professional & scientific | 1994 |
| Alpine Court (Kenilworth) Limited | Households | 1963 |
| Alta Vigo Ltd | Information & communication | 2025 |
| Alto Hearing Kenilworth Ltd | Wholesale & retail | 2023 |
| ALU+ Limited | Manufacturing | 2005 |
| ALU+ Powder Coating Limited | Manufacturing | 2008 |
| Alve Components Ltd | Wholesale & retail | 2015 |
| Alvis Cars Limited | Manufacturing | 2009 |
| Alwalton Hill Peterborough LLP | | 2010 |
| AM Investco Limited | Real estate | 2024 |
| Ambleside Cottages Limited | Hospitality | 2018 |
| AME Forklifts Ltd | Manufacturing | 2017 |
| Amesla Medical Ltd | Health & social care | 2022 |
| Amigo Industry and Trade Co., Ltd. | Professional & scientific | 2019 |
| AMJ Strip OUT Limited | Water & waste | 2020 |
| AML Installations Ltd | Construction | 2015 |
| Amlifecoaching Limited | Health & social care | 2019 |
| Ampac Holding Ltd | Extraterritorial | 1999 |
| AMR Financial Planning Ltd | Professional & scientific | 2024 |
| Anchorgate Property Ltd | Real estate | 2026 |
| Angel International Trade Co., Limited | Administrative & support | 2015 |
| Angela Reed Limited | Wholesale & retail | 2007 |
| Angelcrest Limited | Other services | 2025 |
| Angelice Industry & Trade Co., Limited | Wholesale & retail | 2018 |
| Anji CBL INT Co., Ltd | Extraterritorial | 2014 |
| Anno Smithy Ltd | Extraterritorial | 2016 |
| Anron Enterprise Limited | Extraterritorial | 2018 |
| Ansui | Financial services | 2018 |
| Antelope Motor Cycle Club (Coventry) Limited(The) | Arts & recreation | 1952 |
| Antigo Ltd. | Wholesale & retail | 2014 |
| Anton Construction Limited | Construction | 2013 |
| Anton Gerard Limited | Construction | 2012 |
| Apex Controls Ltd | Other services | 2012 |
| Apex Geotechnical Services Ltd | Professional & scientific | 2021 |
| Apian Consultancy Limited | Information & communication | 2016 |
| Apkpur Limited | Professional & scientific | 2019 |
| Aplasco Industry Co., Ltd | Extraterritorial | 2017 |
| Apollo (Cadcam) Ltd | Information & communication | 2026 |
| Applepippincowshed Management Ltd | Real estate | 2022 |
| APPLIC8 Limited | Manufacturing | 2001 |
| Applied Diamond (Products) Limited | Construction | 1996 |
| Aqua Mechanical Ltd | Construction | 2017 |
| Aquapal Co., Ltd | Administrative & support | 2022 |
| Aquarius Interiors Limited | Manufacturing | 2014 |
| AR HR Consult Limited | Administrative & support | 2013 |
| ARB Matters Limited | Professional & scientific | 2012 |
| Arbortrack Systems Limited | Professional & scientific | 1996 |
| Arbour Network Solutions Limited | Professional & scientific | 2017 |
| Archigiano Design Limited | Extraterritorial | 2018 |
| Archihope (UK) Ltd | Extraterritorial | 2019 |
| Archways Care Ltd | Health & social care | 2003 |
| Arcobaleno Limited | Administrative & support | 1997 |
| Arden's Cafe (Kenilworth) Ltd | Hospitality | 2024 |
| Arden:Twenty Limited | Information & communication | 2017 |
| Ardmona Global Ltd | Professional & scientific | 2019 |
| Arera International Trading Limited | Administrative & support | 2014 |
| Arete Events Limited | Arts & recreation | 2023 |
| Aristo (U.K) Garment Limited | Administrative & support | 2012 |
| Ariston Appliances (Italy) Co., Ltd. | Extraterritorial | 2017 |
| Arktri Ltd | Wholesale & retail | 2024 |
| Arlington Associates Limited | Professional & scientific | 2023 |
| Armona International Limited | Wholesale & retail | 2018 |
| Armorial Properties Ltd | Real estate | 2022 |
| Aromflex Limited | Real estate | 1998 |
| Arraheeq Community Centre Ltd | Other services | 2011 |
| Artichoke Consulting Limited | Health & social care | 2026 |
| Asdm Infotech Limited | Information & communication | 2015 |
| Asdm Property Limited | Real estate | 2020 |
| Ashow Ventures Ltd | Real estate | 2021 |
| Asia Source Co., Limited | Administrative & support | 2020 |
| Asiabest Furniture Co., Ltd | Administrative & support | 2017 |
| Aspec Consultancy Limited | Professional & scientific | 2008 |
| Aspire Safety Technology Co., Ltd. | Extraterritorial | 2017 |
| Assist EV Limited | Manufacturing | 2021 |
| Association of Drainage Authorities | Information & communication | 2014 |
| Astar Harvest Ltd | Extraterritorial | 2018 |
| Astara Limited | Education | 2001 |
| Asys Engineering Ltd | Professional & scientific | 2019 |