| Amcm Mechanical Ltd | Construction | 2019 |
| Ameirro Ltd | Wholesale & retail | 2024 |
| Amelia Care Limited | Health & social care | 2022 |
| Amex Project Management Ltd. | Professional & scientific | 2017 |
| AMH Mobile Smart Repairs Limited | Wholesale & retail | 2021 |
| Amyka International Ltd | Wholesale & retail | 2025 |
| Anaari Retail Ltd | Wholesale & retail | 2024 |
| Anagke & Daughters Limited | Information & communication | 2011 |
| Ancestral Pet Supplements Limited | Wholesale & retail | 2025 |
| Andrew Curphey Theatre Company Ltd | Arts & recreation | 2012 |
| Andrew Murray Associates Limited | Professional & scientific | 2015 |
| ANF Housing Ltd | Real estate | 2024 |
| Angel Bakes Ltd | Manufacturing | 2025 |
| Angel Dust (Widnes) Ltd | Wholesale & retail | 2020 |
| Angel Youth Support Ltd | Health & social care | 2026 |
| Angela Denise Solutions Ltd | Professional & scientific | 2020 |
| Animal Teach Ltd | Education | 2021 |
| Anke Interiors Ltd | Manufacturing | 2026 |
| Antcfitness Ltd | Arts & recreation | 2026 |
| Antonine Hub Limited | Real estate | 2023 |
| Antrobus Properties NW Ltd | Real estate | 2024 |
| Apex Infrastructure AI Limited | Information & communication | 2026 |
| Apex Pipeline Services Limited | Professional & scientific | 2026 |
| Apex Roofing Solutions Ltd | Construction | 2021 |
| Apexridge Auto Group Limited | Wholesale & retail | 2024 |
| API Medical Limited | Health & social care | 2018 |
| APO Learning Ltd | Professional & scientific | 2025 |
| Apokra Ltd | Health & social care | 2014 |
| Apph Aviation Services Limited | Manufacturing | 1985 |
| Apph Nottingham Limited | Manufacturing | 1987 |
| Applecore-It Ltd | Information & communication | 2009 |
| Appleton Utility Holdings Ltd | Financial services | 2019 |
| Appliance Spare Parts UK Ltd | Wholesale & retail | 2020 |
| Apricus Holdings NW Limited | Financial services | 2024 |
| Aqib Solutions Ltd | Wholesale & retail | 2025 |
| Aqua Valets NW Ltd | Administrative & support | 2024 |
| Aquabond Limited | Manufacturing | 2002 |
| AR Plumbing Heating and GAS Services Ltd | Construction | 2025 |
| ARC Brickwork Limited | Construction | 2013 |
| Arch Motors Limited | Manufacturing | 2015 |
| Arcs Marketing Limited | Information & communication | 2025 |
| Arcus Eco Ltd | Wholesale & retail | 2024 |
| Ardelean & SON Limited | Transport & logistics | 2017 |
| Aribilola Ventures Ltd | Administrative & support | 2025 |
| ARK (Facility and Property) Services Limited | Construction | 2003 |
| ARM (NW) Ltd | Transport & logistics | 2021 |
| Armitt Group Limited | Transport & logistics | 2015 |
| ARN Trans Ltd | Transport & logistics | 2018 |
| Arriveconnected Ltd | Information & communication | 2023 |
| ARU Consulting Limited | Administrative & support | 2019 |
| Arven Industrial Chemicals Limited | Manufacturing | 1982 |
| Arvia Water Technologies Limited | Professional & scientific | 2021 |
| Asbestos Associated UK Ltd | Water & waste | 2012 |
| ASC Handling Limited | Transport & logistics | 2013 |
| Ascent Arboriculture Ltd | Administrative & support | 2020 |
| ASH Wood Joinery NW Ltd | Construction | 2022 |
| Ashaj Worldwide Ltd | Extraterritorial | 2025 |
| Ashe Morris Ltd | Professional & scientific | 2000 |
| Ashe Morris Trustee Ltd | Administrative & support | 2008 |
| Ashgate Park Logistics Ltd | Transport & logistics | 2022 |
| Ashley Martin Photography Limited | Professional & scientific | 2014 |
| Ashleys and Co Garage Services Ltd | Manufacturing | 2010 |
| Ask'O Jewellers Limited | Wholesale & retail | 2004 |
| Aspire People Solutions Limited | Administrative & support | 2024 |
| Assent Financial Services Limited | Financial services | 2013 |
| Asset Lifecycle Solutions (North) Limited | Water & waste | 2022 |
| Asset Lifecycle Solutions Limited | Water & waste | 2022 |
| Associated GAS Commercial Ltd | Real estate | 2022 |
| Astburyco Ltd | Real estate | 2022 |
| Astech Projects Limited | Professional & scientific | 1995 |
| Aster Accountants Limited | Professional & scientific | 2013 |
| Astmoor Bridge Garage Limited | Wholesale & retail | 2012 |
| Astranordic Research Ltd | Professional & scientific | 2025 |
| Astrius Holdings Limited | Financial services | 2020 |
| Astrius Limited | Professional & scientific | 2018 |
| Astrius Midlands Limited | Other services | 2023 |
| Atherton Plant Services Limited | Manufacturing | 2021 |
| Athru Consulting Ltd | Wholesale & retail | 2019 |
| Atkins Cottle Electrical Ltd | Professional & scientific | 2013 |
| Atlantis Farm Ltd | Wholesale & retail | 2022 |
| Atlcollectibles Ltd | Wholesale & retail | 2025 |
| ATN Electrical Contractors Limited | Construction | 2020 |
| Auto Club International Ltd | Transport & logistics | 2025 |
| Automotive Horizon Ltd | Administrative & support | 2019 |
| AV Control Systems Limited | Manufacturing | 2006 |
| Avant Movable Walls Ltd | Construction | 2020 |
| Avant Property Group Ltd | Construction | 2022 |
| Avant Property Services Ltd | Real estate | 2026 |
| Avant Risk Management Limited | Administrative & support | 2014 |
| Aviation Servicing Company Ltd | Transport & logistics | 2008 |
| Awakened Company Limited | Wholesale & retail | 2019 |
| Axle Weight Technology Limited | Manufacturing | 1991 |
| Axscend Group Limited | Financial services | 2007 |
| Axscend Limited | Manufacturing | 2001 |
| Axtax Accountants Limited | Professional & scientific | 2013 |
| Axtax Company Services Ltd | Professional & scientific | 2018 |
| Axtax Wages & Pensions Ltd | Professional & scientific | 2018 |
| Axtec Business Services LLP | | 2013 |
| Axtec International Limited | Professional & scientific | 2010 |
| Axtec LLP | | 2010 |