| Amir Portfolio Ltd | Real estate | 2024 |
| Amnis Electrical Ltd | Construction | 2020 |
| AMY Daniels Property Investment Limited | Real estate | 2020 |
| ANA Portfolio Ltd | Real estate | 2014 |
| Anchored Beacon Limited | Administrative & support | 2025 |
| Anderson Carriage Company Limited | Extraterritorial | 2010 |
| Anderson Mckay Ltd | Real estate | 2018 |
| Andover Variety Store Ltd | Wholesale & retail | 2022 |
| Andrew's Pvcu Supplies Ltd | Wholesale & retail | 2000 |
| Andys Haircare Limited | Wholesale & retail | 2024 |
| Angel Hair & Beauty Salon Ltd | Other services | 2012 |
| Animal Trainer's Workshops Ltd | Other services | 2025 |
| Anito V Limited | Wholesale & retail | 2019 |
| Aniya & Adriel Homes Ltd | Real estate | 2026 |
| Anna Car Wash Ltd | Administrative & support | 2025 |
| Annapurna Property Limited | Real estate | 2024 |
| Anny Superstore Ltd | Wholesale & retail | 2017 |
| ANS Prosper Ltd | Transport & logistics | 2024 |
| Ansell & Clarke LLP | | 2009 |
| ANT in the Room Ltd | Professional & scientific | 2023 |
| Ant's Flying Ants Limited | Information & communication | 2018 |
| Anthony Sieben Ltd | Arts & recreation | 2020 |
| Anugraha Bullion Ltd | Wholesale & retail | 2023 |
| Anugraha Gold House Ltd | Wholesale & retail | 2025 |
| Anugraha Homes PVT Ltd | Real estate | 2024 |
| Anugraha Watches Limited | Wholesale & retail | 2022 |
| Any-Base Any-Place Limited | Other services | 2018 |
| AOE Energy Ltd | Construction | 2023 |
| AP Gardens Ltd | Administrative & support | 2025 |
| AP GRG Ltd | Real estate | 2025 |
| APD Studio Ltd | Information & communication | 2007 |
| Apex Direct Mail Limited | Manufacturing | 2003 |
| Apex Service Ltd | Administrative & support | 2014 |
| Apolo Consultancy Services Limited | Information & communication | 2017 |
| Apothecary of Artemis Ltd | Wholesale & retail | 2024 |
| Apple Moving Ltd | Administrative & support | 2018 |
| Apple Tree Grove Management Limited | Households | 2025 |
| Applok Ltd | Information & communication | 2025 |
| April Construction Limited | Construction | 2025 |
| April Tellam Ltd | Other services | 2025 |
| APS Media Ltd | Financial services | 2021 |
| Aptli Limited | Information & communication | 2022 |
| Aquajen Environmental Services Ltd | Water & waste | 2021 |
| Aquastay Limited | Extraterritorial | 2021 |
| Arcadia Cleaning Services Limited | Administrative & support | 2003 |
| Arcadia Studio Limited | Professional & scientific | 2014 |
| Archi Soft Ltd | Information & communication | 2020 |
| Arclith Ltd | Professional & scientific | 2026 |
| Arcom (Holdings) Limited | Information & communication | 1998 |
| Arcom IT Limited | Information & communication | 1995 |
| Areace Consultancy Limited | Administrative & support | 2021 |
| Arena Cars Limited | Wholesale & retail | 2001 |
| Ares Automotive Ltd | Wholesale & retail | 2025 |
| Arian Stores Limited | Wholesale & retail | 2006 |
| Aribas Property Holding Ltd | Real estate | 2026 |
| ARK, Home of God's Children Ministries | Other services | 2023 |
| Armstrong Services Limited | Professional & scientific | 2015 |
| Army Golf Club Limited | Hospitality | 2020 |
| Army Rugby Union Trust | Arts & recreation | 2012 |
| Army Winter Sports Association | Arts & recreation | 2011 |
| ARN Estate Ltd | Real estate | 2025 |
| ARO Services Ltd | Construction | 2016 |
| Artemis Apothecary Ltd | Wholesale & retail | 2024 |
| Artemis Candles Ltd | Wholesale & retail | 2021 |
| Artemis Crafts Ltd | Wholesale & retail | 2022 |
| Arthur Street Property Limited | Real estate | 2018 |
| Arunsini Limited | Construction | 2018 |
| Aryaiman Limited | Real estate | 2025 |
| AS Family Ltd | Real estate | 2024 |
| AS Rental Cars Ltd | Administrative & support | 2025 |
| AS Tihm Ltd | Real estate | 2022 |
| ASH Church Mews Association RTM Company Limited | Extraterritorial | 2024 |
| ASH Church Mews Ltd | Real estate | 2020 |
| ASH Convenience Store Limited | Wholesale & retail | 2024 |
| ASH House Vets Limited | Professional & scientific | 2010 |
| ASH Lodge Close Management Company Ltd | Households | 2021 |
| ASH Road Service Centre Limited | Wholesale & retail | 2021 |
| ASH Street Management Company Limited | Administrative & support | 2012 |
| ASH Vale Metal Recycling Ltd | Wholesale & retail | 2019 |
| ASH Vale Wines Ltd | Wholesale & retail | 2024 |
| Ashbourne Court Residential Care Home Limited | Health & social care | 2004 |
| Ashir Holdings Ltd | Real estate | 2019 |
| Ashir Jewellery Limited | Wholesale & retail | 2017 |
| Ashla & Co Limited | Arts & recreation | 2025 |
| Ashley Sales & Marketing Ltd | Wholesale & retail | 2026 |
| Ashpyr Ltd | Real estate | 2020 |
| Ashworth Communications Limited | Information & communication | 2004 |
| Asia Oriental Super Market Ltd | Wholesale & retail | 2024 |
| Asian Fast Food Ltd | Hospitality | 2022 |
| Asian Grocery Ltd | Wholesale & retail | 2010 |
| Asiaoriental Store Limited | Wholesale & retail | 2013 |
| Asjchippy Ltd | Hospitality | 2023 |
| Asmaratraders Ltd | Wholesale & retail | 2020 |
| Asset Finance and Management (Solutions) Limited | Extraterritorial | 2004 |
| Asset Lettings Limited | Real estate | 2008 |
| Asset Review Consulting Limited | Professional & scientific | 2017 |
| Association of Slovak Schools & Communities UK CIC | Education | 2024 |
| AST Cafe Ltd | Hospitality | 2023 |
| Asteron Ltd | Education | 2025 |
| ASV Best Build Ltd | Construction | 2024 |