| AL Appliances and Repairs Ltd | Wholesale & retail | 2020 |
| AL Roya AL Mustadaama Limited | Professional & scientific | 2025 |
| Alara YAZ Ltd | Hospitality | 2025 |
| Alarms 4 Scaffolding Limited | Construction | 2009 |
| Alarms ARE US Limited | Wholesale & retail | 2017 |
| Albany Leasing Limited | Administrative & support | 2026 |
| Albion Street Mast Limited | Real estate | 2011 |
| ALD Electrical Solutions Limited | Construction | 2025 |
| Aldenham Flat 5 Ltd | Real estate | 2025 |
| Alert 24/7 Security Ltd | Administrative & support | 2024 |
| ALG Spedition Ltd | Transport & logistics | 2022 |
| Alina Cars & Services Ltd | Wholesale & retail | 2026 |
| ALL About the Blue Limited | Hospitality | 2026 |
| ALL in Rental Solutions Ltd | Information & communication | 2023 |
| Allergy London Limited | Health & social care | 2016 |
| Almo Builders Ltd | Professional & scientific | 2024 |
| Alpha Smiles Ltd | Health & social care | 2025 |
| Alpha Systems Consulting Limited | Information & communication | 2024 |
| Alum International Ltd | Wholesale & retail | 2022 |
| Amac Electrical Solutions Ltd | Construction | 2021 |
| Amanova Ltd | Transport & logistics | 2025 |
| Amara Bespoke Ltd | Real estate | 2017 |
| Amara Ealing Ltd | Construction | 2024 |
| Amara Heritage Limited | Construction | 2025 |
| Amara House Ltd | Real estate | 2022 |
| Amara North London Limited | Real estate | 2024 |
| Amarion Art Ltd | Wholesale & retail | 2025 |
| Ambassador Group Ltd | Real estate | 2024 |
| Ambermed Limited | Professional & scientific | 2006 |
| Amcgt Nexus Ltd | Wholesale & retail | 2026 |
| Amco Electrical Services Ltd | Extraterritorial | 2021 |
| AMF Plumbing & Heating Limited | Construction | 2007 |
| Ammej Limited | Real estate | 2017 |
| AMS Design Limited | Professional & scientific | 2020 |
| Anaya & Alia Property Holdings Ltd | Real estate | 2019 |
| ANC Care Holdings Limited | Financial services | 2026 |
| ANC Care Limited | Financial services | 2018 |
| AND Beyond Records Limited | Information & communication | 2025 |
| Anda Investment Property Limited | Real estate | 2023 |
| Andorma Property Co. Limited | Real estate | 1964 |
| Andrena Furniture Ltd | Manufacturing | 1981 |
| Andreul Construct Limited | Construction | 2014 |
| Angels Properties Ltd | Real estate | 2024 |
| Anjani Properties Ltd | Real estate | 2018 |
| ANP Solutions Ltd | Information & communication | 2013 |
| ANS Property Group Ltd | Real estate | 2024 |
| Anso Skin Ltd | Other services | 2026 |
| Anteambulo Advisory Global Ltd | Professional & scientific | 2025 |
| Antene Satelit Londra Ltd | Information & communication | 2023 |
| Anthony Clifton Consulting (a C C) Limited | Professional & scientific | 2018 |
| Anton London Residential Ltd | Real estate | 2019 |
| Antonino-Stelian HAT Ltd | Transport & logistics | 2025 |
| Aosr Limited | Real estate | 2016 |
| AP Diagnostics Limited | Health & social care | 2014 |
| AP Tiling Services Limited | Other services | 2018 |
| APC Training Limited | Education | 2006 |
| APD Accountants Ltd | Professional & scientific | 2022 |
| Apex Tennis Coaching Ltd | Education | 2020 |
| Aphrodite Taverna Ltd | Hospitality | 2023 |
| Apical IT Solutions Limited | Information & communication | 2005 |
| APS Exteriors UK Ltd | Manufacturing | 2025 |
| AR & VS Limited | Wholesale & retail | 2015 |
| ARB (BMS Sevices) Limited | Administrative & support | 2008 |
| Archy Express Limited | Transport & logistics | 2015 |
| Argyle Care Limited | Financial services | 2021 |
| Arkley Scaffolding Ltd | Construction | 2020 |
| Arkley's Little Acorns Nursery Ltd | Education | 2013 |
| ARM Empire Ltd | Real estate | 2020 |
| Armakab Health Limited | Health & social care | 2025 |
| Armakab Ltd | Real estate | 2022 |
| Armar Bunker Services Limited | Administrative & support | 1999 |
| Art Consulting Limited | Administrative & support | 2026 |
| Artjunky Productions Limited | Information & communication | 2020 |
| ARW Specialist Building Contractors Limited | Construction | 2005 |
| Aryan Infotech UK Ltd | Wholesale & retail | 2025 |
| Arzoo Property Ltd | Real estate | 2023 |
| AS Trade Ltd | Wholesale & retail | 2025 |
| Ascend Properties & Investments Ltd | Real estate | 2020 |
| Ascension Combat League Ltd | Arts & recreation | 2025 |
| Ashish Investments Limited | Real estate | 2016 |
| Ashridge Wealth Management Limited | Financial services | 2017 |
| Asource Global Limited | Information & communication | 1988 |
| Aspiring Media Limited | Information & communication | 2021 |
| Aspiring Minds Limited | Professional & scientific | 2023 |
| Asrex Properties Ltd | Real estate | 2020 |
| Asset Time Invest Limited | Real estate | 2016 |
| AT63 Ltd | Professional & scientific | 2026 |
| ATA Marketing Limited | Wholesale & retail | 2020 |
| ATD Food Limited | Wholesale & retail | 2025 |
| ATG Basketball Ltd | Education | 2026 |
| Athelia Property Developments Limited | Real estate | 2019 |
| Athena Frozen Food Private Limited | Wholesale & retail | 2024 |
| Atkinson Appliance Repairs Ltd | Other services | 2026 |
| Atrstam Limited | Wholesale & retail | 2016 |
| Audio Visual Logix Ltd | Other services | 2011 |
| Audition Limited | Construction | 2021 |
| Auravive Ltd | Other services | 2026 |
| Aurum Consult Limited | Professional & scientific | 2025 |
| Aurum Dental Care UK Ltd | Health & social care | 2021 |
| Austin LEE Resourcing Limited | Administrative & support | 2011 |