| Artisan Contractors (B'Ham) Limited | Construction | 2022 |
| Artisan Plant Services Limited | Administrative & support | 2018 |
| AS Hashmi Limited | Real estate | 2025 |
| AS Waste Solutions Limited | Water & waste | 2022 |
| As-Tech Systems Limited | Information & communication | 1996 |
| ASA Blurton Developments Ltd | Real estate | 2021 |
| ASA Medical Locums Ltd | Health & social care | 2015 |
| Asap Fire Safety Management Ltd | Professional & scientific | 2024 |
| ASC001-IIII Holdings Limited | Financial services | 2024 |
| ASC001-IIII Limited | Financial services | 2023 |
| ASC002-III Holdings Limited | Financial services | 2023 |
| ASC002-III Limited | Financial services | 2023 |
| ASC003-II Holdings Limited | Financial services | 2023 |
| ASC003-II Limited | Financial services | 2023 |
| ASC004-I Devco Limited | Construction | 2024 |
| ASC004-I Holdings Limited | Financial services | 2023 |
| ASC004-I Limited | Real estate | 2023 |
| ASC005 Holdings Limited | Financial services | 2023 |
| ASC005 Limited | Financial services | 2023 |
| ASC005B Limited | Construction | 2023 |
| ASC005C Limited | Construction | 2023 |
| ASC005D Limited | Construction | 2023 |
| ASC005E Limited | Construction | 2023 |
| ASC006 Holdings Limited | Financial services | 2023 |
| ASC006 Limited | Construction | 2023 |
| ASC006A Limited | Construction | 2022 |
| ASC5 Limited | Financial services | 2023 |
| Ascension Planning Limited | Professional & scientific | 2013 |
| Ascension Supplements Ltd | Wholesale & retail | 2026 |
| Ascent Accountancy Ltd | Professional & scientific | 2023 |
| ASE Cleaning & Maintenance Ltd | Administrative & support | 2005 |
| Aseo Limited | Wholesale & retail | 2014 |
| ASG Transport Ltd | Transport & logistics | 2010 |
| ASH Project Management Services Ltd | Construction | 2023 |
| ASH Tyres Ltd | Wholesale & retail | 2017 |
| Ashabana Limited | Health & social care | 2013 |
| Ashby Road Construction Limited | Construction | 2013 |
| Ashcliff Limited | Manufacturing | 1991 |
| Ashfall Ltd | Education | 2019 |
| Ashgreen Estates Limited | Extraterritorial | 2006 |
| Ashley Blake Limited | Transport & logistics | 2006 |
| Ashley James Solicitors Limited | Professional & scientific | 2013 |
| Ashleyeducationalservices Limited | Education | 2025 |
| Ashna W Properties Ltd | Real estate | 2025 |
| Ashoora Limited | Hospitality | 2019 |
| Ashta Management Consultancy Limited | Professional & scientific | 2016 |
| Ashton & Ebbutt Limited | Extraterritorial | 1965 |
| Ashton Ebbutt Holdings Limited | Extraterritorial | 1965 |
| Ashton Memorials Limited | Extraterritorial | 1973 |
| Ashton-Gray Consulting Ltd | Professional & scientific | 2017 |
| Ashtons (Brighton) Limited | Extraterritorial | 1944 |
| Ashwood Veterinary Clinic Limited | Professional & scientific | 2012 |
| Asia Manufacturing Limited | Manufacturing | 2015 |
| Asian Communications Network Ltd | Professional & scientific | 2024 |
| Asian Fire Service Association CIC | Education | 2024 |
| Asian Mini Market Ltd | Wholesale & retail | 2019 |
| Askelite Ltd | Information & communication | 1997 |
| Askillaun Consulting Ltd | Administrative & support | 2025 |
| Asla Automation Ltd | Manufacturing | 2019 |
| Asman PVT Ltd | Real estate | 2024 |
| Aspect Adventure Ltd | Education | 2023 |
| Aspect Management Company (Penkridge) Limited | Households | 2024 |
| Aspects Quality Services Ltd | Construction | 2015 |
| Aspire Consulting and Training Ltd | Professional & scientific | 2013 |
| Aspire Empire Ltd | Wholesale & retail | 2021 |
| Aspire People Limited | Administrative & support | 2004 |
| Aspire Project Management Limited | Construction | 2006 |
| Aspired Careers Limited | Administrative & support | 2025 |
| Aspirion Ltd | Wholesale & retail | 2024 |
| Aspt Associates Ltd | Professional & scientific | 2012 |
| Asquith Butler Limited | Manufacturing | 2003 |
| Assentia Ltd | Information & communication | 2011 |
| Assessment and Intervention Services Limited | Health & social care | 2022 |
| Asset North Ltd | Real estate | 2021 |
| Assist Construction Limited | Construction | 2024 |
| Assist Corporation Limited | Professional & scientific | 2008 |
| Assist Developments Limited | Construction | 2024 |
| Assist Homes Limited | Construction | 2025 |
| Assist International Group Limited | Professional & scientific | 2018 |
| Assist Oak Capital Limited | Real estate | 2025 |
| Assist Property Limited | Real estate | 2023 |
| Assist Supporting Accommodation CIC | Hospitality | 2025 |
| Associated Funeral Services Limited | Extraterritorial | 1983 |
| Associated Sports Qualifications LLP | | 2011 |
| Assured Care Southport Limited | Other services | 2016 |
| Assured Investment Services Ltd. | Real estate | 2017 |
| Assured Lifestyle Limited | Health & social care | 2007 |
| Astarfmclimatec Limited | Professional & scientific | 2023 |
| Astc Limited | Professional & scientific | 2015 |
| Asthetika Limited | Administrative & support | 2014 |
| Astley Funerals Limited | Extraterritorial | 1999 |
| Aston BIN Manufacturing Company Ltd | Manufacturing | 2015 |
| Aston Distribution Ltd | Wholesale & retail | 2021 |
| Aston Knowles Limited | Real estate | 2013 |
| Aston Park Grange Management Company Limited | Households | 2006 |
| Aston Property Investments Ltd | Real estate | 2021 |
| Aston Wood Golf Club Limited | Arts & recreation | 2012 |
| Astonhouse Holdings Limited | Real estate | 2024 |
| Astor, Straus & Guggenheim Ltd | Real estate | 2025 |
| Astria Marla Limited | Other services | 2014 |