| Antonia Mann Limited | Manufacturing | 2015 |
| Antonio Giovanni Limited | Other services | 1999 |
| Antonopoulos Services Limited | Transport & logistics | 2015 |
| Antony Retail Services Ltd | Wholesale & retail | 2022 |
| Antu Tech Limited | Wholesale & retail | 2026 |
| Antzworkers Limited | Construction | 2017 |
| Anupco Limited | Wholesale & retail | 1976 |
| Anvil Tooling Limited | Wholesale & retail | 2015 |
| Anxhelita Limited | Professional & scientific | 2026 |
| Anyit Limited | Information & communication | 2008 |
| Anything Print Limited | Extraterritorial | 2015 |
| Anytime Anywhere Couriers UK Ltd | Administrative & support | 2024 |
| AOF Associates Limited | Real estate | 2024 |
| Aoura Health Group Ltd | Health & social care | 2025 |
| AP Enviro Pest Ltd | Administrative & support | 2024 |
| Apex Build Anglia Limited | Construction | 2016 |
| Apex Catering Ltd | Hospitality | 2022 |
| Apex Cooling Solutions Limited | Wholesale & retail | 2002 |
| Apex Fleet Solutions Ltd | Wholesale & retail | 2025 |
| Apex Garden Ltd | Wholesale & retail | 2023 |
| Apex Roofing Anglia Limited | Construction | 2012 |
| Apexascent Sports Ltd | Extraterritorial | 2026 |
| APH Motor Works Ltd | Wholesale & retail | 2023 |
| APH Technology Ltd | Information & communication | 2024 |
| Aphrodite Enterprises Limited | Administrative & support | 2016 |
| APJ Property Limited | Real estate | 2023 |
| Aplus Mobile Ipswich Ltd | Other services | 2024 |
| Apollo Property Holdings Ltd | Real estate | 2019 |
| Apollo RF Consulting Limited | Information & communication | 2011 |
| Appcraft Limited | Information & communication | 2022 |
| Applaud Coffee Ipswich Limited | Hospitality | 2025 |
| Applaud Coffee Limited | Hospitality | 2018 |
| Appleby Social Work Limited | Health & social care | 2022 |
| Appledrive Ltd | Construction | 2023 |
| Applejack.Co.Uk Limited | Information & communication | 2000 |
| Applesquare Limited | Professional & scientific | 2015 |
| Appletree Aircon Services Ltd | Professional & scientific | 2022 |
| Applied Build Solutions Limited | Manufacturing | 2022 |
| Applyrapid Property Management Limited | Real estate | 1995 |
| Appmetize Ltd | Information & communication | 2020 |
| Appnalysis Limited | Information & communication | 2023 |
| Approsta Ltd | Information & communication | 2024 |
| Approved Relocation Limited | Real estate | 2018 |
| Apqs Services Limited | Professional & scientific | 2025 |
| Aptl Enterprises Ltd | Professional & scientific | 2013 |
| APW Training Limited | Health & social care | 2003 |
| AQ Accountancy Ltd | Professional & scientific | 2025 |
| AQ Traffic Solutions Ltd | Construction | 2025 |
| Aqua Force Cleaning Services Ltd | Administrative & support | 2025 |
| Aquae Sulis Investments Limited | Real estate | 2015 |
| Aquae Sulis Lending Limited | Financial services | 2022 |
| Aquae Sulis Management Limited | Real estate | 2015 |
| Aquagrain Limited | Manufacturing | 2016 |
| Aquamar (2001) Ltd | Administrative & support | 2001 |
| Aquasmart Solutions Ltd | Construction | 2024 |
| AQUATIX-2U Limited | Wholesale & retail | 2008 |
| Aquila Sites Ltd | Information & communication | 2024 |
| AR Dental Clinic Ltd | Health & social care | 2024 |
| AR17 Transport Ltd | Transport & logistics | 2019 |
| ARA Carpentry & Building Ltd | Construction | 2021 |
| Arachne Ecology Limited | Professional & scientific | 2012 |
| Arap (EN) Ltd | Hospitality | 2021 |
| Arax Global Limited | Information & communication | 2014 |
| ARB Services Ltd | Real estate | 2021 |
| Arbor Inns Ltd | Hospitality | 2019 |
| Arboriculture and Ecology Consultancy Limited | Professional & scientific | 2019 |
| Arboris Ltd | Information & communication | 1998 |
| ARC Delivery Solutions Limited | Administrative & support | 2024 |
| Arcape International Ltd | Professional & scientific | 2011 |
| Archer Healthcare Limited | Administrative & support | 2024 |
| Archer Offshore Limited | Administrative & support | 2023 |
| Archer Resourcing Ltd | Administrative & support | 2018 |
| Archer Robotics Limited | Administrative & support | 2023 |
| Archex Limited | Information & communication | 2025 |
| Archill Ltd | Construction | 2024 |
| ARCHITECT-4U Ltd | Professional & scientific | 2011 |
| Architekton Limited | Construction | 2014 |
| Archive Live Limited | Wholesale & retail | 2025 |
| Archway Carpets Limited | Wholesale & retail | 2003 |
| Arctic Commando Ltd | Professional & scientific | 2018 |
| Arcvio Ltd | Information & communication | 2025 |
| Ardealu Transport Ltd | Transport & logistics | 2019 |
| Ardega Limited | Administrative & support | 2005 |
| Ardent Lift Consultancy Ltd. | Construction | 2012 |
| Ardent OIL Resources Limited | Information & communication | 2021 |
| Arduino Chambers Ltd | Professional & scientific | 2023 |
| Ardy Property Limited | Real estate | 2024 |
| Area 86 Srls Ltd | Administrative & support | 2025 |
| Area Landscape Architects Limited | Administrative & support | 2006 |
| Area Vending Services Ltd | Wholesale & retail | 2022 |
| Areen Property Ltd | Real estate | 2026 |
| Areion Enforcement Services Ltd | Administrative & support | 2024 |
| Areion Security Services Ltd | Administrative & support | 2022 |
| ARF Stores Ltd | Wholesale & retail | 2024 |
| Argos Property Limited | Real estate | 2018 |
| Argussy Ltd | Wholesale & retail | 2025 |
| ARH Fitness Limited | Other services | 2005 |
| Arham Enterprizes Ltd | Wholesale & retail | 2025 |
| Arhani Ltd | Transport & logistics | 2025 |
| Aria Solutions Limited | Wholesale & retail | 2016 |