| AL Hidayah Asian Grocery Limited | Wholesale & retail | 2020 |
| AL Ltd | Extraterritorial | 2008 |
| Alan Martin Engineering Limited | Professional & scientific | 2017 |
| Alastar Limited | Administrative & support | 2025 |
| Albendan Limited | Real estate | 2017 |
| Alchemy Travel Limited | Administrative & support | 2016 |
| Aldbury Products Ltd. | Manufacturing | 2006 |
| Alden Accountancy Services Limited | Professional & scientific | 2000 |
| Alden Taxation Services Limited | Professional & scientific | 2000 |
| Alertsec Ltd | Information & communication | 2005 |
| Alex Graham Publishing Ltd | Information & communication | 2024 |
| Alexandr Star Ltd | Construction | 2023 |
| Alfa Bond Limited | Construction | 2021 |
| Alfred & Sons Limited | Professional & scientific | 2022 |
| Algek Flooring Limited | Construction | 2006 |
| ALI Supermarket Ltd | Wholesale & retail | 2009 |
| ALL Saints News & Wines Ltd | Wholesale & retail | 2021 |
| ALL SUB Ventures Limited | Hospitality | 2018 |
| Alliance Brazilian JIU Jitsu Ltd | Arts & recreation | 2026 |
| Almath Energy Limited | Energy | 2026 |
| ALN Carpentry Limited | Construction | 2025 |
| ALN Estates Management Ltd | Households | 2025 |
| ALN Group Holdings Ltd | Financial services | 2023 |
| Alphabio Control Limited | Professional & scientific | 2000 |
| Altano UK Limited | Financial services | 2024 |
| Although Digital Ltd | Professional & scientific | 2022 |
| Aluminati Network Group Limited | Wholesale & retail | 2003 |
| Alycidon Mews Management Company Limited | Extraterritorial | 2015 |
| Alysha Optical Ltd | Professional & scientific | 2017 |
| Amanda COX Interiors Limited | Professional & scientific | 2005 |
| Amazing Grace Network Ltd | Health & social care | 2020 |
| Ammos Catering Ltd | Hospitality | 2024 |
| AMO Racing Holdings Limited | Financial services | 2021 |
| AMO Racing Limited | Arts & recreation | 2003 |
| AMO Racing Stables Limited | Professional & scientific | 2022 |
| AMS (EA) Ltd | Construction | 2010 |
| AMY Murphy Racing Ltd. | Arts & recreation | 2016 |
| Andbash Ltd | Professional & scientific | 2023 |
| Anderson Developments (EA) Limited | Households | 2026 |
| Andre Webb Property Management Limited | Real estate | 2012 |
| Andrew Matthews Ltd | Wholesale & retail | 2009 |
| Andrew Pollard Ltd | Construction | 2002 |
| Anergreen Properties Limited | Real estate | 2003 |
| Angel Newmarket Limited | Professional & scientific | 2025 |
| Anglia Business Club Ltd | Other services | 2020 |
| Anglia Comedy Ltd | Arts & recreation | 2025 |
| Anglia Fabrication & Design Limited | Manufacturing | 1969 |
| Anglia Investors Limited | Financial services | 2024 |
| Anglia Landscaping Limited | Administrative & support | 2023 |
| Anglia OIL Tanks Ltd | Construction | 2012 |
| Anglia Surfacing Limited | Construction | 2025 |
| Anglia Towbars (Newmarket) Limited | Wholesale & retail | 2007 |
| Anglian HR Support Services Ltd | Administrative & support | 2026 |
| Anglian Precision Limited | Manufacturing | 1993 |
| Anna Hall Limited | Professional & scientific | 2012 |
| Anne Larkin Limited | Professional & scientific | 2015 |
| Another Dimension Limited | Information & communication | 1993 |
| Another Way Learning & Development Ltd | Education | 2015 |
| Anthony DE Grey Trellises Limited | Administrative & support | 1998 |
| Anthony Stroud Bloodstock Limited | Professional & scientific | 1986 |
| Anthrotek Ltd | Manufacturing | 2024 |
| Antler Construction Ltd | Construction | 2020 |
| AP Carpentry Services Ltd | Construction | 2020 |
| AP Ltd | Extraterritorial | 2009 |
| AP Studland Store Ltd | Wholesale & retail | 2019 |
| Apex Charlie Ltd | Extraterritorial | 2017 |
| Apex Outdoor Projects Ltd | Administrative & support | 2024 |
| Aphilia Community Care Ltd | Health & social care | 2026 |
| Apic System Design Limited | Construction | 2019 |
| Apical Landscaping Limited | Professional & scientific | 2018 |
| Aplas Window Solutions (ELY) Limited | Construction | 2025 |
| Aplas Window Solutions Limited | Construction | 2015 |
| App Street Limited | Information & communication | 2011 |
| Appliance Care & Repair Limited | Other services | 2012 |
| Aquaid Franchising Limited | Wholesale & retail | 1998 |
| AR Cafe Ltd | Hospitality | 2019 |
| AR Suffolk Limited | Wholesale & retail | 2019 |
| Aracom Industries Limited | Manufacturing | 2021 |
| Aracom Investments Limited | Construction | 2024 |
| Aragon Court Investments Limited | Real estate | 2001 |
| Arash Motor Company Limited | Manufacturing | 2000 |
| Arash Technologies Limited | Professional & scientific | 2020 |
| Arborfield Drive Management Ltd | Households | 2012 |
| ARC Pubs Ltd | Hospitality | 2022 |
| Arcada (NKT) Limited | Real estate | 2020 |
| Ardenfort Estates Ltd | Hospitality | 2025 |
| Ardross Court Management Limited | Households | 1989 |
| Argamia Bloodstock Limited | Administrative & support | 2011 |
| Arglo Limited | Financial services | 2024 |
| ARI AG Invest Ltd | Information & communication | 2025 |
| Aristo Balustrades Ltd | Construction | 2024 |
| Arlind Car Wash Limited | Administrative & support | 2024 |
| Arlo Imports Ltd | Administrative & support | 2026 |
| Arrowsmith Estates Ltd | Real estate | 2017 |
| Arrowsmith Insurance Services Limited | Extraterritorial | 1991 |
| Arstarios Contract Consulting Services Ltd | Professional & scientific | 2026 |
| Art Decodesign Limited | Wholesale & retail | 2004 |
| Artemis Studio Limited | Manufacturing | 2025 |
| Arvoda UK Limited | Wholesale & retail | 2023 |
| As&Sd Feast Ltd | Manufacturing | 2022 |