| Altitude Business Consultancy and Training Limited | Professional & scientific | 2013 |
| Ambarya International PVT Ltd | Wholesale & retail | 2025 |
| Amems Siteline Boring & Machining Ltd | Real estate | 2015 |
| AML Health Ltd | Health & social care | 2021 |
| AMP Medical Solutions Ltd | Health & social care | 2026 |
| Amsb Properties Ltd | Real estate | 2019 |
| Andrew Evans Industrial Roofing and Cladding Limited | Construction | 2017 |
| Andrew James Property Surveyors and Valuers Ltd | Professional & scientific | 2013 |
| Andrew Nevil Riley Ltd | Transport & logistics | 2013 |
| Andy Bell Properties Limited | Real estate | 2018 |
| Andy Dent Limited | Transport & logistics | 2012 |
| Angel Coffee Shop Limited | Hospitality | 2024 |
| Angel Trust Trading Limited | Water & waste | 2023 |
| Anjalinas Health Limited | Health & social care | 2022 |
| ANR Retail Store Ltd | Wholesale & retail | 2023 |
| ANT Brown Limited | Hospitality | 2015 |
| Anthony Shoulder Roofing Ltd | Construction | 2015 |
| Antony Iveson Management Services Limited | Professional & scientific | 2019 |
| APD Electrotech Ltd | Construction | 2012 |
| Apex Hospitality Collective Limited | Hospitality | 2025 |
| Apex Photography.Com Limited | Professional & scientific | 2026 |
| Apperley View Management Ltd | Households | 2023 |
| Aquacktic Swim School Ltd | Arts & recreation | 2011 |
| AR Electrical (NE) Ltd | Construction | 2022 |
| Araby Law and Ethics Ltd | Administrative & support | 2025 |
| Arbeia Investments Limited | Real estate | 2024 |
| Architectural Design Workshop Ltd | Professional & scientific | 2010 |
| Areteshop Ltd | Wholesale & retail | 2022 |
| Armiger Joinery Limited | Construction | 2004 |
| Armour Clad UK NE Ltd | Construction | 2026 |
| Armstrong Electrical Engineering Ltd | Construction | 2025 |
| Armstrong Fabrication Limited | Manufacturing | 2025 |
| Armstrong Holdings Northern Limited | Other services | 2021 |
| Armstrong’S Sweet Treats Ltd | Hospitality | 2021 |
| Arran Court (Bishop Auckland) Limited | Real estate | 2004 |
| Arrelleff Ltd | Other services | 2018 |
| Arrow Cars Ripon Ltd | Transport & logistics | 2025 |
| Arrow Commercial Limited | Construction | 1988 |
| Arthur Heseltine Limited | Transport & logistics | 1973 |
| AS Plasterers Ltd | Construction | 2022 |
| ASA Roofing & Groundwork’S Ltd | Construction | 2026 |
| Ashbrooke Stud Ltd. | Agriculture & fishing | 2019 |
| Ashburn Engineering Ltd | Manufacturing | 2019 |
| Ashcare Solutions Limited | Health & social care | 2017 |
| ASL (Highway Electrical) Training Limited | Other services | 2013 |
| ASL Powerstream Services Limited | Administrative & support | 2009 |
| Asmag UK Limited | Extraterritorial | 2008 |
| Asna C&C Limited | Wholesale & retail | 2023 |
| Asna Spice House Limited | Wholesale & retail | 2024 |
| Aspen Energy Services Ltd | Construction | 2023 |
| Aspire Home Improvements N.E Limited | Construction | 2019 |
| Aspire Homes N.E Limited | Real estate | 2019 |
| Aspire Roofing NE Ltd | Construction | 2024 |
| Aspire Roofing Services Northern Ltd | Construction | 2023 |
| Aspirex Global Consulting Ltd | Professional & scientific | 2024 |
| Aspyrian Labs Ltd | Information & communication | 2024 |
| Asquith Interiors Limited | Manufacturing | 2015 |
| Assets Specialists Ltd | Wholesale & retail | 2020 |
| Atag Design Ltd | Manufacturing | 2023 |
| ATD Agri Ltd | Agriculture & fishing | 2023 |
| Atech Transport Limited | Transport & logistics | 2021 |
| Athelstan Property Services Limited | Households | 2015 |
| Athelstane Crescent Management Company Limited | Households | 2014 |
| Athena Sports Academy Limited | Arts & recreation | 2013 |
| Atlas Accommodation Limited | Hospitality | 2023 |
| Atlas Property Sourcing Ltd | Administrative & support | 2026 |
| Atlas Taxis Management Limited | Administrative & support | 2015 |
| Atozspice Ltd | Hospitality | 2026 |
| ATR Caravan Sales Limited | Wholesale & retail | 2008 |
| Atra Property Ltd | Real estate | 2024 |
| Attain BES Limited | Construction | 2021 |
| Attuned Communications & Marketing Limited | Information & communication | 2022 |
| ATV North Limited | Manufacturing | 2003 |
| Auckland Alehouses Ltd | Hospitality | 2026 |
| Auckland Brewer Limited | Hospitality | 2021 |
| Auckland C2P Design Ltd | Professional & scientific | 2019 |
| Auckland Car Valeting Centre Ltd | Other services | 2022 |
| Auckland Cycle Works Ltd | Manufacturing | 2023 |
| Auckland Decorators Ltd | Construction | 2022 |
| Auckland Dental Practice Limited | Health & social care | 2007 |
| Auckland Developments Ltd | Construction | 2025 |
| Auckland Electrical & Security Systems Limited | Construction | 2006 |
| Auckland Housing Limited | Real estate | 2020 |
| Auckland Interiors Ltd | Construction | 2021 |
| Auckland Panda Limited | Hospitality | 2021 |
| Auckland Property Estates Limited | Real estate | 2003 |
| Auckland Scaffolding Ltd | Construction | 2016 |
| Auckland Scientific Limited | Professional & scientific | 2017 |
| Auckland Sheet Metal Limited | Manufacturing | 1999 |
| Auckland Sunbed Hire Limited | Administrative & support | 2016 |
| Auckland Taxis Ltd | Transport & logistics | 2025 |
| Auckland Travel Ltd | Transport & logistics | 2020 |
| Auckland Youth and Community Centre Limited | Arts & recreation | 2006 |
| Auckside Motors Ltd | Wholesale & retail | 2002 |
| Audio Visual and Networking Services Ltd | Construction | 2018 |
| Aurora Stone Limited | Manufacturing | 2024 |
| Austin Gladwell Ltd | Financial services | 2026 |
| Auto & Engine Services Ltd | Wholesale & retail | 2025 |
| Automotive Solutions North East Limited | Wholesale & retail | 2026 |
| Autoworksba Ltd | Professional & scientific | 2025 |