| Andrew Francis Maintenance Contractors Ltd | Construction | 2014 |
| Andrew James Enforcement Limited | Administrative & support | 2003 |
| Andrew James Holdings Limited | Real estate | 2005 |
| Andrew James Property Limited | Construction | 2005 |
| Andrew S Jones Solutions Limited | Professional & scientific | 2015 |
| Andrew Scott Ltd. | Construction | 1946 |
| Andrew Wedlake Electrical Limited | Construction | 2011 |
| Andrew's Landscape Design Ltd | Administrative & support | 2004 |
| Andrewb Software Development Limited | Information & communication | 2024 |
| Andrews & Kent Carpenters Limited | Manufacturing | 2020 |
| Andrews Capital Limited | Real estate | 2018 |
| Andy Cabs Limited | Transport & logistics | 2025 |
| Andyforker Ltd | Professional & scientific | 2015 |
| ANE Law Limited | Extraterritorial | 2011 |
| Anesca Limited | Professional & scientific | 2014 |
| Angel Chambers Limited | Real estate | 2007 |
| Angel Dance Company Ltd | Education | 2020 |
| Angela Limited | Wholesale & retail | 2021 |
| Angelcarecymru Ltd | Health & social care | 2025 |
| Angelcarewales Ltd | Health & social care | 2018 |
| Angell PUB Co Ltd | Hospitality | 2024 |
| Angels 2015 Ltd | Other services | 2015 |
| Angies Snack Shack Ltd | Hospitality | 2023 |
| Angletop Limited | Real estate | 1994 |
| Angus Medical Limited | Health & social care | 2026 |
| Animal and Garden Supplies Ltd | Wholesale & retail | 2011 |
| Anitya Systems Ltd | Information & communication | 2022 |
| ANN Physiocare Limited | Information & communication | 2012 |
| Anna Kosowska Ltd | Health & social care | 2023 |
| Anneddfa Consulting Ltd | Professional & scientific | 2024 |
| Annielou Ltd | Information & communication | 2025 |
| Annjohnproperty Ltd | Real estate | 2025 |
| Anns Crane Hire Limited | Administrative & support | 2024 |
| Annwen Limited | Information & communication | 2020 |
| Another Salon Limited | Other services | 2019 |
| Anroch Limited | Hospitality | 2017 |
| ANS and Eden Properties Limited | Real estate | 2023 |
| Ansar Helping Hands | Other services | 2019 |
| ANT Complete Heat Ltd | Wholesale & retail | 2025 |
| ANT Supplies Limited | Wholesale & retail | 2010 |
| Antebellum 42 Ltd | Hospitality | 2023 |
| Antelope Trading Limited | Extraterritorial | 2009 |
| Anthony D. Bates Partnership LLP | | 2009 |
| Anthony Inkin & Paul Deans Limited | Other services | 2006 |
| Anthony's Garage Ltd | Wholesale & retail | 2021 |
| Anti-Damp Limited | Wholesale & retail | 2024 |
| Antlin Plumbing & Heating Limited | Construction | 2011 |
| Anton Developments Limited | Construction | 1994 |
| Anton Homes Limited | Construction | 2001 |
| Anton Property Holdings Limited | Real estate | 2000 |
| Antonio's Art Gallery Limited | Wholesale & retail | 2019 |
| Antonios Film Catering Ltd | Hospitality | 2022 |
| Anubis Software Ltd | Information & communication | 2024 |
| Anvil Flat Roofing Limited | Construction | 2024 |
| Anvil Roofing Limited | Construction | 2021 |
| Anxiety Support Wales CIC | Education | 2021 |
| ANY Training Group Ltd | Education | 2022 |
| Anytime Cars Limited | Wholesale & retail | 2018 |
| AO Accountancy Services Limited | Professional & scientific | 2024 |
| AO GAS Ltd | Construction | 2019 |
| AOM Solutions Limited | Professional & scientific | 2016 |
| Aonb Property Ltd | Construction | 2025 |
| AOS Consultancy Ltd | Professional & scientific | 2025 |
| Aotea Design Ltd | Professional & scientific | 2012 |
| Apache Tyres Ltd | Manufacturing | 2016 |
| Apartment 119 Limited | Administrative & support | 2012 |
| Apartment 6 Ltd | Wholesale & retail | 2018 |
| Apco Installations Ltd | Administrative & support | 2016 |
| Apex Anaesthetic Solutions Limited | Health & social care | 2026 |
| Apex Custom Carpentry Ltd | Construction | 2025 |
| Apex Industrial Cleaning Solutions Ltd | Administrative & support | 2025 |
| Apex Technical & Construction Ltd | Manufacturing | 2015 |
| Apexion Couriers Ltd | Transport & logistics | 2026 |
| APH Mechanical Engineering Services Limited | Professional & scientific | 2026 |
| APH Systemcare Ltd | Administrative & support | 2008 |
| API Financial Services Limited | Financial services | 2015 |
| Apollo Contractors Ltd | Manufacturing | 2015 |
| Apollo Property Trading Ltd | Real estate | 2019 |
| Apollo Scaffolding Wales Limited | Construction | 2015 |
| Apollo SPV Ltd | Real estate | 2022 |
| Apollonia Finance Corp Limited | Other services | 2025 |
| Apotheca Limited | Extraterritorial | 2001 |
| Appear Online Limited | Professional & scientific | 2023 |
| Appearlogic Limited | Transport & logistics | 2021 |
| Apple Developments (Swansea) Limited | Real estate | 2008 |
| Apple Invest Limited | Real estate | 2017 |
| Applebeck Limited | Information & communication | 2018 |
| Appliance Express Contracts Ltd | Manufacturing | 2013 |
| Appliance Team (Swansea) Limited | Other services | 2006 |
| Applied Artists and Makers Co Ltd. | Arts & recreation | 2001 |
| Applied Control Systems Ltd | Manufacturing | 2013 |
| Applied Post Tensioning Solutions Limited | Administrative & support | 2008 |
| Applied Property Investments Ltd | Real estate | 2026 |
| Appos Systems Ltd | Information & communication | 2019 |
| Approved Property Solutions Ltd | Construction | 2018 |
| Aprc Ltd | Professional & scientific | 2015 |
| Apro Building Limited | Manufacturing | 2024 |
| Apropos Software Ltd. | Information & communication | 2018 |
| Aptoa Ltd | Professional & scientific | 2019 |
| AQK Limited | Wholesale & retail | 2001 |