| Alef London Limited | Professional & scientific | 2023 |
| ALG Decorators Ltd | Construction | 2023 |
| Algar Property Management Ltd | Real estate | 2022 |
| Algar Road Management Limited | Households | 2022 |
| Alhamd Foods Ltd | Hospitality | 2024 |
| Alhuda Transport Ltd | Transport & logistics | 2019 |
| Alice Barat Limited | Information & communication | 2016 |
| Alicefit Ltd | Arts & recreation | 2025 |
| Alif Parfums Limited | Wholesale & retail | 2024 |
| Alison Campbell Associates Ltd | Professional & scientific | 2011 |
| Aliyans Imaging Limited | Health & social care | 2020 |
| ALL Homes Investments Ltd | Real estate | 2017 |
| ALL Spice 'N' Nice Ltd | Hospitality | 2025 |
| Allen Care Ltd | Health & social care | 2015 |
| Allergic Media Limited | Information & communication | 2025 |
| Allestate Properties Ltd | Real estate | 1998 |
| Allied Tricore Services Ltd | Transport & logistics | 2025 |
| Alln Limited | Information & communication | 2023 |
| Allrounder Limited | Real estate | 1999 |
| Alma Medical Limited | Health & social care | 2016 |
| Almondspring Ltd | Information & communication | 2019 |
| ALP Training Limited | Education | 2018 |
| Alpas Psychology Ltd | Health & social care | 2019 |
| Alpencare Limited | Real estate | 2008 |
| Alpha Sculptoris Ltd | Manufacturing | 2022 |
| Alphabet Daycare Limited | Health & social care | 2024 |
| Alphashape Limited | Health & social care | 2014 |
| Alphaville Construction Ltd | Construction | 2019 |
| Alpine AI Ltd | Information & communication | 2025 |
| Althurst Limited | Real estate | 1999 |
| Alvir Ltd | Construction | 2022 |
| Always & Forever Limited | Wholesale & retail | 1998 |
| ALZAK7 Ltd | Wholesale & retail | 2026 |
| AM Electrics ETC Ltd | Construction | 2014 |
| AM Screeds Ltd | Construction | 2023 |
| Amana Homes Ltd | Hospitality | 2024 |
| Amax Retrofit Limited | Professional & scientific | 2022 |
| Amber Key Property Solutions Ltd | Real estate | 2023 |
| Ambifest Ltd | Administrative & support | 2024 |
| Ambreen Consultancy Limited | Professional & scientific | 2025 |
| AMC Motors Group Ltd | Wholesale & retail | 2024 |
| AMC Motors Solutions Ltd | Wholesale & retail | 2024 |
| Amena Legal Services Limited | Professional & scientific | 2026 |
| Ameris Homes Ltd | Real estate | 2022 |
| Ames Always Limited | Wholesale & retail | 2024 |
| Amex Foods Limited | Extraterritorial | 2019 |
| Amex Retail Limited | Extraterritorial | 2019 |
| Amex Worldwide Limited | Extraterritorial | 2019 |
| AMI Care Properties Limited | Real estate | 2025 |
| AMI Home Care Limited | Health & social care | 2017 |
| Amjad Farooq Ltd | Wholesale & retail | 2026 |
| AML Beauty Limited | Wholesale & retail | 2026 |
| Amojet Ltd | Health & social care | 2026 |
| Amreece Limited | Wholesale & retail | 2026 |
| Amui Venture Limited | Professional & scientific | 2015 |
| ANA Prime Estate Limited | Real estate | 2024 |
| ANA Property Investments Limited | Real estate | 2017 |
| ANA Trida Well-Being Ltd | Other services | 2020 |
| Anac Thai Limited | Hospitality | 2025 |
| Anaesthetico Limited | Health & social care | 2023 |
| Anak Thai Limited | Hospitality | 2025 |
| Anand Real Eastate Limited | Households | 2022 |
| Anchor Relocation Ltd | Professional & scientific | 2024 |
| Anda BA Ltd | Professional & scientific | 2024 |
| Andmore London Ltd | Wholesale & retail | 2024 |
| Andrastar Limited | Financial services | 2007 |
| Andres Construction Ltd | Construction | 2017 |
| Andrew Fisher Consulting Limited | Financial services | 2024 |
| Angel Steelfixing Ltd | Construction | 2024 |
| Angelina Colarusso Limited | Manufacturing | 2006 |
| Angelov 84 Ltd | Other services | 2020 |
| Anglo Arabian Foods Limited | Extraterritorial | 2015 |
| Angylite Limited | Health & social care | 2019 |
| ANI Systems Robotics & Automation Services Ltd | Administrative & support | 2016 |
| Anjna Limited | Wholesale & retail | 2023 |
| Ankamarka Ltd | Wholesale & retail | 2021 |
| Anly Limited | Wholesale & retail | 2026 |
| Annggik Limited | Real estate | 2025 |
| Anro Accounting Solutions Limited | Professional & scientific | 2012 |
| Anro Financial Planning Limited | Financial services | 2018 |
| Ansh Stores Ltd | Wholesale & retail | 2024 |
| Anshika Communications Limited | Wholesale & retail | 2018 |
| Antelj Management Ltd | Financial services | 2016 |
| Anthony James Manser Limited | Real estate | 1998 |
| Antique Rugs Ltd | Manufacturing | 2019 |
| Antonix Technologies Ltd | Information & communication | 2026 |
| AOK Fitness Limited | Other services | 2017 |
| AP PM Solutions Ltd | Information & communication | 2025 |
| Apex Arthur Consultants Ltd | Professional & scientific | 2026 |
| Apex Premier Limited | Construction | 2021 |
| Apollo Industry Ltd | Wholesale & retail | 2024 |
| Apollo Photographers Limited | Professional & scientific | 1983 |
| Apollo Properties UK Limited | Real estate | 2009 |
| App & Web Innovations Ltd | Information & communication | 2012 |
| Appindex Limited | Information & communication | 2021 |
| Aprilsep Limited | Administrative & support | 2012 |
| Aqsah Khan Ltd | Other services | 2020 |
| Aqua Depot Ltd | Agriculture & fishing | 2014 |
| Aqua Distributors Ltd | Wholesale & retail | 2025 |
| Aquabella London Ltd | Wholesale & retail | 2009 |