| Anston Homes Ltd | Construction | 2020 |
| Anthony a Walker Ltd | Professional & scientific | 2019 |
| ANY Name Will DO Ltd | Other services | 2025 |
| Anything Goes CIC | Wholesale & retail | 2019 |
| Apache Metals Ltd | Water & waste | 2020 |
| Apan Trading Ltd | Wholesale & retail | 2026 |
| Apbranded Limited | Hospitality | 2018 |
| Apcyw Ltd | Wholesale & retail | 2022 |
| Apex Point Logistics Ltd | Transport & logistics | 2025 |
| Apex Protects Ltd | Administrative & support | 2023 |
| APH Executive Travel Limited | Transport & logistics | 2017 |
| APL Trading Ltd | Wholesale & retail | 2024 |
| APM Grimsby Ltd | Real estate | 2018 |
| Apollo Joinery Services Ltd | Construction | 2019 |
| Applejack (GY) Ltd | Other services | 2015 |
| Appleleaf Accountancy and Tax Limited | Professional & scientific | 2016 |
| Appleleaf Limited | Extraterritorial | 2019 |
| Applewick Properties Ltd | Real estate | 2022 |
| Applytical Limited | Information & communication | 2023 |
| Appoint Consulting Limited | Administrative & support | 2018 |
| Approved Property Buyers Ltd | Real estate | 2013 |
| APR Management Ltd | Other services | 2012 |
| Aqua Flow Bathrooms & Plastics Limited | Wholesale & retail | 2019 |
| Aqua Kinetics Ltd | Wholesale & retail | 2011 |
| Aquacrest (UK) Limited | Manufacturing | 1995 |
| Aramuthan Limited | Wholesale & retail | 2025 |
| Arata Digital Ltd | Information & communication | 2026 |
| ARC Construction Solutions Limited | Construction | 2019 |
| ARC Electrical & Instrument Services Ltd | Construction | 2023 |
| Arcadia Healthcare Limited | Administrative & support | 2012 |
| Arcadia Recruitment Limited | Health & social care | 1994 |
| Arcadia Trading Europe Limited | Agriculture & fishing | 2002 |
| Arcam Services Ltd | Professional & scientific | 2021 |
| Archcroft Limited | Hospitality | 2012 |
| Archiem Limited | Health & social care | 2023 |
| Arcteq Ltd | Manufacturing | 2014 |
| Arctic Breeze Fish Products Limited | Manufacturing | 1947 |
| ARD Property Developments Ltd | Construction | 2026 |
| Ardd Property Ltd | Real estate | 2009 |
| Area 2 Area Limited | Wholesale & retail | 2000 |
| Arena Airsoft Ltd | Arts & recreation | 2009 |
| Arfat Trading Ltd | Wholesale & retail | 2023 |
| Argon (Grimsby) Limited | Hospitality | 2026 |
| Argot Services Ltd | Professional & scientific | 2024 |
| ARH Joinery Limited | Construction | 2016 |
| ARIA2025 Ltd | Hospitality | 2025 |
| Arian News Ltd | Other services | 2023 |
| Ariksempire Limited | Wholesale & retail | 2026 |
| Arinka Travel Ltd | Administrative & support | 2024 |
| Arion Catering Limited | Hospitality | 2022 |
| ARK Meridian Ltd | Administrative & support | 2012 |
| Arkitect Hair Extension Academy Limited | Education | 2016 |
| Arloss Ltd | Professional & scientific | 2026 |
| Arminsi Limited | Wholesale & retail | 2025 |
| Armourtex Cycles Limited | Wholesale & retail | 2017 |
| Armstrong Co-Ordination Ltd | Construction | 2020 |
| ARN Electrical Ltd | Construction | 2022 |
| Arne Fabrications Limited | Manufacturing | 2011 |
| Arran Joinery Limited | Construction | 2003 |
| Arrows Consulting Ltd | Professional & scientific | 2000 |
| ARS Trans Ltd | Transport & logistics | 2016 |
| Art to Heart Art Gallery and Grocery Ltd | Wholesale & retail | 2025 |
| ART4GIFT Ltd | Wholesale & retail | 2019 |
| ARTEMIS2 Investments Ltd | Financial services | 2026 |
| Arthur Burton Limited | Real estate | 1965 |
| Artisan Addison Limited | Manufacturing | 2025 |
| Artisan Brushworks Ltd | Construction | 2025 |
| Arumukum Ltd | Wholesale & retail | 2026 |
| Arundel Produce Ltd | Wholesale & retail | 2024 |
| Aryan Cash and Carry Ltd | Wholesale & retail | 2022 |
| ASA Property Services Limited | Other services | 2015 |
| Ascend Payroll Limited | Professional & scientific | 2021 |
| Ascend PSG Limited | Professional & scientific | 2025 |
| Ascend Safety Ltd | Other services | 2026 |
| Ascension Academy Ltd | Education | 2018 |
| Ascent Bath & Body Ltd | Manufacturing | 2021 |
| ASD Enterprises Limited | Extraterritorial | 2012 |
| Asefi Limited | Real estate | 2020 |
| ASF Transport Ltd | Transport & logistics | 2017 |
| ASH Barbers Limited | Other services | 2018 |
| ASH Interiors & Drylining Ltd | Construction | 2016 |
| Ashby Building Services Limited | Construction | 2002 |
| Ashdena & Co Ltd | Professional & scientific | 2026 |
| Ashford & Company Limited | Professional & scientific | 1995 |
| Ashford Associates Properties Limited | Real estate | 1997 |
| Ashlar Developments Lincs Ltd | Real estate | 2026 |
| Ashley Morris Joinery Ltd | Construction | 2021 |
| Ashleymccue.Services Ltd | Manufacturing | 2025 |
| Ashworth Controls Ltd | Manufacturing | 2023 |
| Asian Remedies Ltd | Wholesale & retail | 2023 |
| Asiatic Texture Limited | Wholesale & retail | 2019 |
| Asideus Ltd | Information & communication | 2025 |
| ASK Albert Ltd | Information & communication | 2025 |
| ASK Medical Services Ltd | Health & social care | 2018 |
| ASK4VAN Transport Ltd | Transport & logistics | 2024 |
| Askel Property Investments Ltd | Real estate | 2025 |
| Askerton Homes Limited | Construction | 2011 |
| ASM PVT Limited | Transport & logistics | 2017 |
| ASP Builders and Developers Limited | Construction | 2006 |
| Aspect Blinds Installations Ltd | Construction | 2024 |