| Alliance Cooling Services West Midlands Ltd | Construction | 2023 |
| Allied Securities Limited | Real estate | 1999 |
| Allinall Events Limited | Professional & scientific | 2013 |
| Allo Ltd | Wholesale & retail | 2020 |
| Alloquy Limited | Professional & scientific | 2015 |
| Alloy Link Limited | Professional & scientific | 2015 |
| Allton Estates Limited | Real estate | 1930 |
| Allums Jewellers Ltd | Manufacturing | 2004 |
| Allusa Limited | Administrative & support | 2007 |
| ALO Electronics Limited | Professional & scientific | 2025 |
| Alpha Photo Supplies Limited | Professional & scientific | 2006 |
| Alpharhythm Limited | Professional & scientific | 2010 |
| Alpharunning Ltd | Wholesale & retail | 2021 |
| Alton Property Management Limited | Real estate | 1959 |
| Altor Consulting Limited | Mining & quarrying | 2020 |
| ALX Events Limited | Hospitality | 2019 |
| Alyciem Ltd | Information & communication | 2025 |
| AM 2 PM Group Holdings Limited | Administrative & support | 2016 |
| AM 2 PM Recruitment Services (Nationwide) Limited | Administrative & support | 2024 |
| AM 2 PM Recruitment Services Limited | Administrative & support | 2018 |
| AM 2 PM Recruitment Solutions (Birmingham) Limited | Administrative & support | 2006 |
| AM 2 PM Staff Solutions Limited | Administrative & support | 2018 |
| AM 2 PM Training Limited | Administrative & support | 2022 |
| AM Advisory Ltd. | Professional & scientific | 2016 |
| AM Capital Investments Limited | Real estate | 2019 |
| AM Online Resourcing Ltd | Professional & scientific | 2009 |
| AM Resourcing Ltd | Other services | 2007 |
| AMA Garage Services Limited | Wholesale & retail | 2019 |
| Aman Sunner Ltd | Other services | 2021 |
| Amaryllis Consulting Ltd | Construction | 2003 |
| Amazigh Travel and Tours Limited | Other services | 2018 |
| Ambition Personal Training Ltd | Arts & recreation | 2017 |
| AMC Servicing Solutions Limited | Wholesale & retail | 2012 |
| Amethyst Advisory Limited | Education | 2014 |
| Amethyst Marketing Ltd | Professional & scientific | 2012 |
| Amethyst Networks Ltd | Information & communication | 2015 |
| AMG Developments (NW) Ltd | Extraterritorial | 2023 |
| Amington Developments Limited | Real estate | 2001 |
| AML Construction Group Limited | Construction | 2019 |
| Amorartis Bidco Limited | Professional & scientific | 2021 |
| Amorartis Midco Limited | Professional & scientific | 2021 |
| Amos Building Services Limited | Construction | 2013 |
| AMP Eleven Ltd | Professional & scientific | 2026 |
| Amphiris Limited | Professional & scientific | 2026 |
| Ample Ventures Ltd | Real estate | 2022 |
| AMR Media Services Ltd | Professional & scientific | 2023 |
| Amrail (Midlands) Limited | Transport & logistics | 2017 |
| Amspire Ltd | Real estate | 2024 |
| AMT Maintenance Group Ltd | Construction | 2025 |
| Amtrain (Midlands) Limited | Education | 2003 |
| Amtsy Limited | Manufacturing | 2018 |
| AMY Boulden Golf Limited | Arts & recreation | 2015 |
| ANC Attachments Ltd | Wholesale & retail | 2024 |
| Anchor Security Systems Ltd | Manufacturing | 2023 |
| Anco Construction Solutions Ltd | Construction | 2013 |
| Anda Associates Limited | Professional & scientific | 2021 |
| Anderson Catering Ltd | Hospitality | 2017 |
| Andesign Graphics Ltd | Professional & scientific | 2025 |
| Andremio Limited | Professional & scientific | 2023 |
| Andrew Downing-Booth Holdings Limited | Financial services | 2026 |
| Andrew Downing-Booth Lettings Limited | Real estate | 2022 |
| Andrew Downing-Booth Limited | Real estate | 2019 |
| Andrew Foster Consulting Limited | Professional & scientific | 2019 |
| Andy Shaw Developments Ltd | Real estate | 2015 |
| Angel Over My Shoulder Ltd | Wholesale & retail | 2016 |
| Anglo Dutch Connection Limited | Administrative & support | 2017 |
| Animal Exposure Limited | Information & communication | 2020 |
| Animal Matters Ltd | Professional & scientific | 2018 |
| Animinders Ltd | Agriculture & fishing | 2025 |
| Anisa Morridadi Ltd | Professional & scientific | 2024 |
| ANR Site Solutions Limited | Administrative & support | 2024 |
| Ansh Enterprise Ltd | Wholesale & retail | 2013 |
| Ansons Solicitors Limited | Professional & scientific | 2015 |
| Ansons Trust Corporation Limited | Administrative & support | 2024 |
| Anthony D.Harris & Sons Leisure Limited | Arts & recreation | 1975 |
| Anthony John Salons Limited | Other services | 2011 |
| Antiblanks Limited | Information & communication | 2010 |
| Antiference Limited | Wholesale & retail | 1938 |
| Antifragile Enterprises Ltd | Professional & scientific | 2021 |
| Antonia Evans Limited | Education | 2023 |
| Anzuzs Limited | Real estate | 2022 |
| AP Electrical Installations Ltd | Construction | 2025 |
| AP Group Investments Ltd | Financial services | 2025 |
| AP Property Investment Holdings Ltd | Real estate | 2025 |
| AP Wireless (UK) Limited | Real estate | 2011 |
| AP Wireless II (UK) Limited | Real estate | 2012 |
| Apache Product Solutions Limited | Manufacturing | 2021 |
| Apag Limited | Financial services | 2015 |
| APE Group Ltd | Real estate | 2022 |
| Apex Electrical Midlands Ltd | Construction | 2024 |
| Apex Environmental Limited | Agriculture & fishing | 2013 |
| Apex Sport Lounge Limited | Wholesale & retail | 2025 |
| APM Logistics Midlands Limited | Transport & logistics | 2025 |
| Appealing Abodes Ltd | Real estate | 2024 |
| Application Solutions (Electronics and Vision) Limited | Information & communication | 2007 |
| Applied Electric Services Midland Limited | Energy | 2015 |
| Applied Minerals Limited | Wholesale & retail | 2012 |
| Applied Search Technology Limited | Information & communication | 2004 |
| Applio Limited | Information & communication | 2007 |
| Approach Shots Ltd | Wholesale & retail | 2023 |