| Apex Radio Systems Limited | Information & communication | 1990 |
| Apex Services NE Ltd | Construction | 2019 |
| Apex Smart Security Solutions Limited | Information & communication | 2025 |
| APH Hydraulic Engineering Ltd | Manufacturing | 2015 |
| Apix Nutrition Limited | Agriculture & fishing | 2018 |
| APM Cleaning & Repair Ltd. | Households | 2008 |
| Apok Building Services Ltd | Construction | 2012 |
| Apollo Plastics Limited | Manufacturing | 1978 |
| Apollo Studio Limited | Professional & scientific | 2021 |
| Apollomax Limited | Wholesale & retail | 1999 |
| Apollonia Construction Limited | Construction | 2021 |
| Apostu Ltd | Health & social care | 2013 |
| Apparel by Empress Ltd | Manufacturing | 2024 |
| Applause Enterprise Ltd | Administrative & support | 2022 |
| Applegate Hill Limited | Real estate | 2016 |
| Applied Technical Management Services Limited | Professional & scientific | 2015 |
| Approved Fire Doors Limited | Construction | 2024 |
| Appsatile Ltd | Information & communication | 2022 |
| Appsatile PM Ltd | Information & communication | 2023 |
| Appsatile Software Group Ltd | Information & communication | 2021 |
| April Egan Limited | Other services | 2012 |
| Aprograph Sign Systems Ltd | Manufacturing | 2006 |
| APT Facilities Limited | Administrative & support | 2014 |
| APT Property Options Limited | Real estate | 2019 |
| Aqua Bath Coatings Ltd | Professional & scientific | 2012 |
| Aqua TCG Limited | Wholesale & retail | 2026 |
| AR & FA Properties Ltd | Real estate | 2022 |
| AR Enterprise (NE) Limited | Health & social care | 2021 |
| AR Welding (NE) Ltd | Manufacturing | 2025 |
| Aramus Limited | Real estate | 2024 |
| Arborcon Ltd | Financial services | 2016 |
| ARC Cars (North East) Ltd | Wholesale & retail | 2014 |
| ARC Pro Design Solutions Ltd | Professional & scientific | 2008 |
| ARC Repair Limited | Manufacturing | 2017 |
| ARC Surgery Limited | Health & social care | 2021 |
| Arcaas Ltd | Real estate | 2023 |
| Arcadia Care NO1 Limited | Health & social care | 2021 |
| Arcadia Care NO2 Limited | Education | 2022 |
| Arcadia Education (Wolverhampton) Limited | Health & social care | 2022 |
| Arcadia Interactive Limited | Information & communication | 2024 |
| Arcadia Lifestyles Limited | Health & social care | 2021 |
| Arcadia Mining Limited | Health & social care | 2022 |
| Arcadia Property Group Limited | Real estate | 2021 |
| Arcadia Ventures Ltd | Health & social care | 2021 |
| Arcas Building Solutions Limited | Construction | 2013 |
| Arch 16 Limited | Hospitality | 2018 |
| Archer-Ip Limited | Professional & scientific | 2014 |
| Archers Decorators Limited | Construction | 2014 |
| Archspan Construction Ltd | Other services | 2014 |
| Arck Construction Ltd | Construction | 2017 |
| Arcon Cleaning Services Limited | Professional & scientific | 1978 |
| Ardallan Kitchen Ltd | Hospitality | 2022 |
| Ardor Hondo Limited | Wholesale & retail | 2025 |
| Ares Risk Ltd | Administrative & support | 2022 |
| Arezo Limited | Hospitality | 2025 |
| Ario Vape Ltd | Wholesale & retail | 2024 |
| Arissa Lifestyle Protection Specialists Ltd | Financial services | 2021 |
| Ariston Accountants Limited | Professional & scientific | 2011 |
| ARK (NE) Ltd | Manufacturing | 2024 |
| ARK Developments (NE) Ltd | Real estate | 2023 |
| ARK Telecom Ltd | Information & communication | 2017 |
| Armatus Oceanic Ltd | Professional & scientific | 2019 |
| Armourpost Limited | Manufacturing | 1991 |
| Armstrong Roofing Services Limited | Construction | 2011 |
| Armstrong Singh Ltd | Real estate | 2022 |
| Arnet Ltd. | Construction | 1998 |
| Arnet Safety Systems Limited | Construction | 2007 |
| ARP Design Holdings Limited | Financial services | 2016 |
| ARP Design Limited | Professional & scientific | 2003 |
| Arris Masonry NE Limited | Manufacturing | 2024 |
| Arrora Facilities Limited | Real estate | 2025 |
| Arrow Investments Limited | Real estate | 2007 |
| Arrowbond Investments Limited | Real estate | 2011 |
| Arrowsig Developments Ltd | Real estate | 2016 |
| Arrowsmith Property Limited | Real estate | 2024 |
| Artam Solutions Ltd | Real estate | 2025 |
| Artificial Grass NE Limited | Administrative & support | 2022 |
| Artima Homes Limited | Real estate | 2022 |
| Artistribe Ltd | Information & communication | 2023 |
| Artmother Ltd | Arts & recreation | 2021 |
| Arts Media Services (NE) Ltd | Professional & scientific | 2013 |
| Artyant Creations Ltd | Wholesale & retail | 2024 |
| AS & SM Kemp & SON Ltd | Agriculture & fishing | 2024 |
| AS a Matter of ACT Ltd | Arts & recreation | 2019 |
| ASA NE Ltd | Wholesale & retail | 2024 |
| Asad Usman Ltd | Wholesale & retail | 2026 |
| Asal Universal Ltd | Real estate | 2020 |
| Asbestos Audit Ltd | Professional & scientific | 2018 |
| Asbestos Building Consultants Ltd | Administrative & support | 2025 |
| Asbestos Surveying and Monitoring Limited | Professional & scientific | 2026 |
| Ascendant Lifts Limited | Manufacturing | 2003 |
| Asceros International Limited | Wholesale & retail | 2002 |
| Ascot Car Wash Ltd | Other services | 2019 |
| Ascot House Properties Ltd | Households | 2018 |
| Asghar Sports and Prestige Limited | Other services | 2006 |
| Ash's Window Cleaning Windows Gleaming Ltd | Administrative & support | 2023 |
| Ashco Property Investments Ltd | Real estate | 2021 |
| Ashcroft Engineering Limited | Manufacturing | 2013 |
| Ashdale Electrical Solutions Ltd | Construction | 2021 |
| Ashfield Court Freehold Management Company Limited | Households | 2023 |