| Amber U.P.V.C. Fabrications Limited | Wholesale & retail | 1995 |
| Amber U.P.V.C. Holdings Limited | Other services | 1995 |
| Amber U.P.V.C.Windows Limited | Wholesale & retail | 1993 |
| Ambition PS Ltd | Real estate | 2011 |
| Amblehurst Green (Billingshurst) Management Company Limited | Households | 2017 |
| AMD Aspects Limited | Construction | 2015 |
| AMD Therapy Ltd | Other services | 2022 |
| Amee Mcconnell Properties Ltd | Real estate | 2024 |
| Ameleo Limited | Real estate | 2021 |
| Amethyst Partners Ltd | Real estate | 2023 |
| Amethyst Securities Limited | Real estate | 2025 |
| Amex Executive Consulting Ltd | Professional & scientific | 2025 |
| AMG Restaurants Ltd | Hospitality | 2021 |
| Amgfish Ltd | Financial services | 2024 |
| Amicus Building Products Limited | Extraterritorial | 2013 |
| Amillan Holdings Limited | Financial services | 2023 |
| Amillan Limited | Information & communication | 1985 |
| Amin Fratelli Limited | Construction | 2006 |
| Amir Home Furniture Ltd | Manufacturing | 2024 |
| Amira's Pet Pamper Limited | Other services | 2019 |
| Amirtha & Akshaya Ltd | Health & social care | 2021 |
| Amispao Ltd | Wholesale & retail | 2025 |
| Amity Bloc Limited | Professional & scientific | 2019 |
| Amma Childcare Services Ltd | Health & social care | 2020 |
| Ammc Building and Groundworks Limited | Construction | 2021 |
| Amnova Properties Ltd | Real estate | 2025 |
| Amona Associates Ltd | Professional & scientific | 2025 |
| Amoryr Management Ltd | Arts & recreation | 2022 |
| AMP Building Maintenance Limited | Construction | 2023 |
| Ampa Associates Limited | Professional & scientific | 2003 |
| Amplify Marketing Agency Ltd | Administrative & support | 2016 |
| AMQ Investments Ltd | Real estate | 2025 |
| AMR Properties Ltd | Other services | 2014 |
| AMR Technologies Ltd | Professional & scientific | 2010 |
| AMS (Stonemasons) Limited | Manufacturing | 2016 |
| Amsa Group Ltd | Real estate | 2025 |
| Amstra Innovations Limited | Wholesale & retail | 2024 |
| Amuka Limited | Extraterritorial | 2014 |
| AMW Services (Midlands) Limited | Professional & scientific | 2018 |
| AMY Christie Ltd. | Manufacturing | 2006 |
| AMY Claire Consulting Ltd | Administrative & support | 2023 |
| AMZ Business Solutions Ltd | Administrative & support | 2025 |
| AMZ Residential Properties Ltd | Real estate | 2026 |
| Amzt Ltd | Professional & scientific | 2018 |
| Anaesthetic Solutions Midlands Limited | Health & social care | 2016 |
| Ananya Consultancy Solutions Limited | Information & communication | 2023 |
| Anay Software Consultancy Limited | Information & communication | 2013 |
| ANC Business Solutions Ltd | Information & communication | 2018 |
| Anchor Wealth Management Limited | Financial services | 2015 |
| Andalus Universal Ltd | Real estate | 2019 |
| Anderson Moores Veterinary Specialists Ltd. | Professional & scientific | 2005 |
| Andrew Parker Wealth Management Limited | Financial services | 2016 |
| Androu Properties Limited | Professional & scientific | 2006 |
| Andy CHU Design Limited | Professional & scientific | 2019 |
| Andy SAX Ltd | Information & communication | 2004 |
| Andy Thorne Fencing & Landscaping Ltd | Administrative & support | 2015 |
| Andyd Electrical Installations Ltd | Construction | 2014 |
| Anesis Homes Limited | Real estate | 2026 |
| Anew Consulting Ltd | Wholesale & retail | 2020 |
| Anfield Ltd | Other services | 2016 |
| Angel Enterprises Limited | Real estate | 1985 |
| Angels Assistance Ltd | Financial services | 2016 |
| Anglo Furnishings Ltd | Wholesale & retail | 2012 |
| Anglo Italian Arms (Holdings) Limited | Financial services | 2022 |
| Anglo Italian Arms Limited | Wholesale & retail | 2005 |
| Animal Kind Dog Training Ltd | Other services | 2017 |
| Animblusoul Limited | Information & communication | 2026 |
| Aniraj Limited | Wholesale & retail | 2021 |
| Anish Investments Limited | Real estate | 2020 |
| Aniyaana Ltd | Health & social care | 2021 |
| Aniz Visram Accountancy Services Limited | Professional & scientific | 2003 |
| Anmian Limited | Real estate | 2014 |
| Anna Louise Gowns Limited | Wholesale & retail | 2010 |
| Anna's Homes Ltd | Real estate | 2025 |
| Annapercydavis.Com Limited | Information & communication | 2014 |
| Annvor Limited | Wholesale & retail | 2017 |
| Ansrsa Ltd | Manufacturing | 2024 |
| Antela Limited | Hospitality | 2019 |
| Anthony Michael Construction Limited | Construction | 2010 |
| Anthony Verduyn Limited | Professional & scientific | 2022 |
| Anti-Ligature Lighting Company Limited | Wholesale & retail | 2024 |
| ANU Softech Ltd | Information & communication | 2019 |
| Anwar Enterprises Ltd | Health & social care | 2022 |
| ANY Floors Ltd | Wholesale & retail | 2010 |
| Anytime Mortgages Ltd | Financial services | 2023 |
| Anywhere Network Limited | Information & communication | 2007 |
| Aoaura Limited | Real estate | 2025 |
| AOS Developments Ltd | Real estate | 2024 |
| AP & MD Properties LLP | | 2023 |
| AP 95 Limited | Health & social care | 2020 |
| AP Accountants Ltd | Professional & scientific | 2020 |
| AP Finance and Consulting Ltd | Professional & scientific | 2020 |
| AP Management and Engineering Services Limited | Professional & scientific | 2018 |
| AP Property Sourcing Ltd | Real estate | 2025 |
| AP RAD Ltd | Health & social care | 2024 |
| APA Holdings (UK) Ltd | Professional & scientific | 2022 |
| APA Scaffolding Ltd | Construction | 2026 |
| Apache Cat Ltd | Health & social care | 2011 |
| Apal Properties Limited | Real estate | 2013 |
| Apalms Properties Limited | Real estate | 2014 |