| Andersons Property Development Ltd | Real estate | 2026 |
| Andreea Healthcare Professional Ltd | Health & social care | 2020 |
| Andrew Drive Limited | Transport & logistics | 2023 |
| Andrew Paxton Consultancy Services Ltd | Other services | 2021 |
| Andrews Gwynne LLP | | 2006 |
| Andro North Limited | Administrative & support | 2025 |
| Andy Blackburn Ltd | Construction | 2011 |
| Andy Larmouth Ltd | Arts & recreation | 2019 |
| Andy Liddle Associates Limited | Professional & scientific | 2009 |
| Andy Martin Maintenance Ltd | Manufacturing | 2025 |
| Anesty Court (Bishopton) Management Company Limited | Households | 1995 |
| Anglia Lingua Ltd | Information & communication | 2018 |
| Anglo-American Custom Cycle Ltd | Information & communication | 2003 |
| Angolcsomag Ltd | Transport & logistics | 2013 |
| Aniivé Ltd | Health & social care | 2026 |
| Animmersion UK Ltd | Information & communication | 2006 |
| Anisa Shezadi Nawaz Ltd | Health & social care | 2025 |
| Anita Frazer Ltd | Professional & scientific | 2013 |
| Anna Garofalo Consulting Limited | Professional & scientific | 2017 |
| Anoob Albinas Logistics Ltd | Transport & logistics | 2025 |
| Anscomb Civil Engineering Ltd | Construction | 2003 |
| Anthony Alan Foods Ltd | Manufacturing | 2001 |
| Anthonys Motor Services (Teesside) MOT Centre Ltd | Wholesale & retail | 2026 |
| Antlia (Services) Limited | Manufacturing | 2014 |
| Anton Innovation Ltd | Professional & scientific | 2017 |
| Antrobus Inspection Services Limited | Professional & scientific | 2010 |
| Anuyu Aesthetics Ltd | Health & social care | 2026 |
| AP COX Electrical Services Limited | Professional & scientific | 2011 |
| AP Support Assessments Ltd | Education | 2022 |
| AP the Coaching Physio Limited | Other services | 2025 |
| AP Turbine Services Limited | Professional & scientific | 2016 |
| AP03 FX Limited | Public administration | 2025 |
| Apex Bazaar Ltd | Wholesale & retail | 2024 |
| Apex Business Partners Ltd | Professional & scientific | 2023 |
| Apex Detailing Ltd | Wholesale & retail | 2026 |
| Apex Modular Systems Limited | Construction | 2013 |
| Apex Mouthguards Ltd | Health & social care | 2024 |
| Apex Supply and Logistics Ltd | Professional & scientific | 2023 |
| APH Builders Ltd | Construction | 2023 |
| API Microwave Limited | Manufacturing | 2008 |
| Aplu Energy Ltd | Construction | 2022 |
| Apollo Arts Ltd | Education | 2009 |
| Apollo Music Service Ltd | Education | 2011 |
| App North Ltd | Hospitality | 2025 |
| Appledorn Developments Limited | Construction | 2010 |
| Applethatch Property Consultants Limited | Real estate | 2020 |
| Appleton Homes Limited | Construction | 2017 |
| Appletree Day Care Ltd | Health & social care | 2020 |
| APS Cable Solutions Ltd | Construction | 2023 |
| Aqcart Ltd | Wholesale & retail | 2025 |
| Aquarius Design Studio Ltd | Arts & recreation | 2025 |
| Aquila Multi Services Ltd | Real estate | 2018 |
| Aquila Nova Holdings Limited | Professional & scientific | 2026 |
| Aquila Nova Property Limited | Real estate | 2026 |
| AR Property Capital Ltd | Real estate | 2026 |
| Aramil Ltd | Real estate | 2022 |
| Arauk Enterprises Limited | Wholesale & retail | 2023 |
| Arawinabi Ltd | Wholesale & retail | 2026 |
| ARB Property Group Ltd | Real estate | 2025 |
| ARB Property Trading Ltd | Real estate | 2024 |
| ARC Electrical Site Services Ltd | Construction | 2020 |
| ARC Plan & Design Ltd | Professional & scientific | 2026 |
| Arcane Archive Limited | Wholesale & retail | 2025 |
| Arch Building Supplies Limited | Extraterritorial | 1983 |
| Arch Land Ltd | Administrative & support | 2023 |
| Archer Developments Limited | Construction | 2023 |
| Archwade Limited | Water & waste | 2017 |
| Arctic Refrigeration (Bolton) Limited | Construction | 1993 |
| Ardash Ltd | Other services | 2026 |
| Ardex Enterprises Limited | Real estate | 2020 |
| Ardy/S Leisure Ltd | Other services | 2025 |
| Area North Training & Safety Services Limited | Professional & scientific | 2002 |
| Arena Technical Services Limited | Construction | 2003 |
| Argyle Access Ltd | Construction | 2024 |
| Arise 'N' Shine Services Ltd | Administrative & support | 2026 |
| Ariston Property Investments Ltd | Financial services | 2025 |
| ARK Healthcare Services Ltd | Health & social care | 2017 |
| ARK Personnel Ltd | Administrative & support | 2023 |
| ARL Financial Planning Ltd | Financial services | 2020 |
| Arlington Engineering Design Limited | Professional & scientific | 2006 |
| ARM Associates Limited | Real estate | 2025 |
| Armson Construction Ltd | Construction | 2015 |
| Armstrong Electrical (NE) Ltd | Construction | 2010 |
| Armstrong Safety NE Ltd | Professional & scientific | 2018 |
| Arnett Wind and Land Ltd | Construction | 2020 |
| Aroithai 168 Ltd | Hospitality | 2022 |
| ARP7 Consulting Ltd | Professional & scientific | 2023 |
| Arpan Anaesthetics Ltd | Health & social care | 2016 |
| Arrow Detailing Limited | Professional & scientific | 2001 |
| Arrowmark Road Markings Ltd | Construction | 2014 |
| Art of Elegance Ltd | Wholesale & retail | 2025 |
| Artesian Spring Limited | Wholesale & retail | 2024 |
| Arthouzz LLP | | 2022 |
| Artsbank Art Services Limited | Arts & recreation | 2010 |
| ARU ARU Ltd | Professional & scientific | 2014 |
| Arumalla Ltd | Health & social care | 2025 |
| AS IT Consultancy Ltd | Information & communication | 2025 |
| ASA Property Solutions Ltd | Construction | 2012 |
| ASA Roofing / Property Maintenance (N/E) Limited | Construction | 2004 |
| Asbestos Surveys and Removals Ltd | Administrative & support | 2016 |