| Apex Build Pro Ltd | Construction | 2024 |
| Apex Facilities Management Ltd | Households | 2020 |
| Apex Foods Essex Ltd | Hospitality | 2026 |
| Apex Remedial Therapy Ltd | Health & social care | 2025 |
| APJ Contractors Ltd | Construction | 2019 |
| APO Systems Limited | Construction | 2025 |
| Apollo 17 Ltd | Professional & scientific | 2021 |
| Apostille Office UK Limited | Professional & scientific | 2023 |
| Apostolic Action Chapel | Other services | 2008 |
| Apostolic Evangelical Church (UK) | Other services | 2005 |
| App Accountax Ltd | Professional & scientific | 2024 |
| Apploom Studio Ltd | Information & communication | 2024 |
| Apres SKI Party Ltd | Hospitality | 2023 |
| April 10 Limited | Other services | 2019 |
| APS Goods Ltd | Wholesale & retail | 2024 |
| Aqeeq Company Limited | Wholesale & retail | 2022 |
| AQF Trading Limited | Professional & scientific | 2014 |
| Aqua Forum Ltd | Professional & scientific | 2023 |
| Aqua Locums Ltd | Professional & scientific | 2011 |
| Aquanex UK Ltd | Other services | 2025 |
| AQUARIOUS7 Ltd | Wholesale & retail | 2023 |
| Aquil Ltd | Professional & scientific | 2015 |
| AR Kitchen Ltd | Hospitality | 2025 |
| Aravion Signs & Blinds Limited | Wholesale & retail | 2013 |
| Arcadia Riverside Conferences Ltd | Hospitality | 2024 |
| Architecting Link Limited | Administrative & support | 2015 |
| Archlaw Solicitors Ltd | Professional & scientific | 2024 |
| Archtrend Limited | Professional & scientific | 1996 |
| Arcila Records Ltd | Information & communication | 2025 |
| ARD Stylist Limited | Manufacturing | 2021 |
| Arden Day Ltd | Construction | 2023 |
| Arfan Mobile Mechanic Ltd | Wholesale & retail | 2025 |
| Argon & Krypton Consulting Ltd | Professional & scientific | 2022 |
| Argon-Krypton Homes Limited | Real estate | 2017 |
| Ariana Clothing Limited | Wholesale & retail | 2019 |
| Ariana Laundry Services Ltd | Administrative & support | 2025 |
| Arimar Ltd | Transport & logistics | 2026 |
| Ariston Development Ltd. | Education | 2013 |
| Ariston Logistics Ltd | Transport & logistics | 2026 |
| Ariston Professional Cleaners Limited | Administrative & support | 2024 |
| ARK Angel Ltd | Real estate | 2011 |
| ARK Letting and Property Management Limited | Real estate | 2018 |
| Arkare Limited | Wholesale & retail | 2025 |
| Arks Imports & Exports Limited | Wholesale & retail | 2025 |
| Arkume Limited | Wholesale & retail | 2025 |
| ARM Business Ltd | Manufacturing | 2025 |
| Armadi Art Limited | Construction | 2020 |
| Armani Wisnia Properties Ltd | Real estate | 2026 |
| Armin Consultancy Limited | Information & communication | 2019 |
| Armssolution Ltd | Wholesale & retail | 2020 |
| ARN Express Transport Ltd | Transport & logistics | 2026 |
| Arnos Grove Food Centre Limited | Wholesale & retail | 2018 |
| Aroma Facilitate Management Ltd. | Administrative & support | 2016 |
| Arrs Consultancy Limited | Professional & scientific | 2021 |
| ARS Enterpise UK Ltd | Transport & logistics | 2021 |
| Arsalan Property Estates Limited | Real estate | 2017 |
| Arsber Ltd | Households | 2018 |
| Arsh Deals Limited | Wholesale & retail | 2026 |
| Arsh Foods Ltd | Hospitality | 2024 |
| Arso Motor Ltd | Wholesale & retail | 2022 |
| Art Look Ltd | Other services | 2023 |
| Artbit Solutions Ltd | Information & communication | 2026 |
| Artech Consultancy Ltd | Wholesale & retail | 2018 |
| Arteflow Projects Ltd | Professional & scientific | 2026 |
| Arthur Facilities Services Limited | Administrative & support | 2017 |
| Artic Construct Ltd | Construction | 2025 |
| Artisan Meats Ltd | Manufacturing | 2025 |
| Artist and Scientist Limited | Hospitality | 2023 |
| Artistic Expressions Murals Ltd | Arts & recreation | 2025 |
| Artistruct Ltd | Construction | 2025 |
| ARY Constraction Ltd Ltd | Administrative & support | 2025 |
| Arzignano Chiampo Peace Foundation Ltd | Other services | 2022 |
| AS Commerce Limited | Wholesale & retail | 2012 |
| AS Construction Ltd | Construction | 2024 |
| AS Decor Ltd | Construction | 2021 |
| Asaa Constructions Limited | Construction | 2025 |
| Asad Car Rentals Limited | Administrative & support | 2024 |
| Asama Limited | Wholesale & retail | 2024 |
| Asan J Properties Ltd | Real estate | 2021 |
| Asante’S Grill&Catering Ltd | Hospitality | 2026 |
| ASB Team Ltd | Construction | 2021 |
| Ascent GLO Ltd | Administrative & support | 2017 |
| ASD Consulting Limited | Hospitality | 2013 |
| ASF Immigration Services Ltd | Professional & scientific | 2025 |
| Asfcrew Ltd | Construction | 2020 |
| ASH Car Clinic Ltd | Wholesale & retail | 2025 |
| Asha Parade Ltd | Hospitality | 2024 |
| Ashalie Company Ltd | Health & social care | 2022 |
| Ashdown RTM Company Limited | Households | 2021 |
| Ashley Devon Corporation Ltd | Professional & scientific | 2025 |
| Ashoka London Limited | Education | 2022 |
| Ashti Property Ltd | Construction | 2023 |
| Ashurst Building Services Limited | Professional & scientific | 2024 |
| Ashurst Operations and Services Limited | Information & communication | 2024 |
| Ashvans Ltd | Transport & logistics | 2026 |
| Asian Food Store Ltd | Wholesale & retail | 2020 |
| Asian Trade Fair Limited | Hospitality | 2019 |
| Asiatic Limited | Wholesale & retail | 2008 |
| Asiatic Properties Limited | Real estate | 2020 |
| Asim E.Com Ltd | Wholesale & retail | 2025 |