| 121MED Ltd | Transport & logistics | 2021 |
| 121MED Training Ltd | Education | 2025 |
| 14 Morgan Street Ltd | Real estate | 2025 |
| 1ST Class Body Repairs Ltd | Wholesale & retail | 2016 |
| 21ST Century Fogs Limited | Wholesale & retail | 2019 |
| 29 Market Street RTM Company Limited | Households | 2025 |
| 2D Building Contractors Ltd | Construction | 2010 |
| 3 Star Catering Ltd | Hospitality | 2018 |
| 3D RUG Shop Ltd | Wholesale & retail | 2024 |
| 3EA Ltd | Real estate | 2018 |
| 4MATIX Limited | Administrative & support | 2011 |
| 4OCUS Limited | Wholesale & retail | 2014 |
| 71 TBR & Co CYF | Hospitality | 2022 |
| 888 Consultancy Ltd | Professional & scientific | 2019 |
| A M Supplier Ltd | Wholesale & retail | 2019 |
| A Spray Paintworks Limited | Wholesale & retail | 2021 |
| A Tale of Ltd | Information & communication | 2023 |
| A Wardhaugh Consulting Ltd | Professional & scientific | 2024 |
| A.C.K. Farming Limited | Agriculture & fishing | 2021 |
| A1 Book Keeping (Bridgend) Ltd | Professional & scientific | 2010 |
| A2H Live Limited | Administrative & support | 2020 |
| A2H Live Properties Limited | Real estate | 2026 |
| Abacoustics Limited | Administrative & support | 2008 |
| Abason Limited | Real estate | 2023 |
| ABC of Opera Ltd | Information & communication | 2016 |
| ABC of Opera Productions Ltd | Arts & recreation | 2018 |
| ACB Training Ltd | Professional & scientific | 2013 |
| Accountable South Wales Limited | Professional & scientific | 2011 |
| ACT (Accept, Challenge & Transform) Fitness Ltd | Manufacturing | 2019 |
| ACT Community Ltd | Administrative & support | 2023 |
| Active Construction Projects Ltd | Construction | 2019 |
| Active Self Defence UK Ltd | Arts & recreation | 2014 |
| AD Services (Cardiff) Ltd | Administrative & support | 2010 |
| Adamrbaker Scouting Ltd | Arts & recreation | 2024 |
| Adrian Curtis Limited | Professional & scientific | 2017 |
| Advent Box Company Ltd | Wholesale & retail | 2025 |
| Adwill Associates Limited | Administrative & support | 2016 |
| Aesthetic Perm Skin Ltd | Other services | 2025 |
| Afon Community Dance C.I.C. | Arts & recreation | 2024 |
| AGT Holdings Limited | Financial services | 2023 |
| Aimanic Ltd | Information & communication | 2024 |
| AIS Retailers Ltd | Wholesale & retail | 2024 |
| Akol Care Ltd | Construction | 2020 |
| Alan Johns Media Ltd | Manufacturing | 2025 |
| Alex Glew Music Ltd | Education | 2024 |
| Alterations Suite Ltd | Manufacturing | 2024 |
| Altitude Wellness Clinic Ltd | Health & social care | 2025 |
| Alyse Marie Laing Limited | Extraterritorial | 2025 |
| Amility Services Ltd | Wholesale & retail | 2025 |
| Ammonite Yarns Ltd | Wholesale & retail | 2015 |
| AMY Clarke Limited | Information & communication | 2015 |
| Anderton Legal Services Ltd | Professional & scientific | 2019 |
| Anvil Auto Care Limited | Hospitality | 1995 |
| AP Accounting Solutions Limited | Professional & scientific | 2014 |
| AP Dine-In Ltd | Hospitality | 2025 |
| Apex Print and Display Ltd | Manufacturing | 2026 |
| Apex Race Rooms Ltd | Manufacturing | 2023 |
| Apex Windscreens Limited | Wholesale & retail | 2025 |
| Apglan CYF | Arts & recreation | 2021 |
| App Electrical Ltd | Construction | 2021 |
| Appletree Kitchens Ltd | Wholesale & retail | 2011 |
| APW Facilities Ltd | Construction | 2009 |
| Arbitrary Ventures Ltd | Information & communication | 2022 |
| Ardal Leagues Southern Ltd | Arts & recreation | 2020 |
| Arena Supplies Limited | Manufacturing | 1992 |
| Argoed Quarry Ltd | Extraterritorial | 2009 |
| Arlais Ltd | Professional & scientific | 2026 |
| Artisanal Homes Ltd | Construction | 2024 |
| Artwork With Aluminium and Glass Limited | Construction | 2019 |
| AS( (Wales) Ltd | Wholesale & retail | 2016 |
| Ascend Stays Ltd | Households | 2026 |
| Aspin Roofing Specialists Ltd | Construction | 2018 |
| Aspire TEC Limited | Manufacturing | 2025 |
| Assesswell Social Work Ltd | Health & social care | 2025 |
| AST Decorators Ltd | Construction | 2025 |
| Athlete Career Connect Ltd | Administrative & support | 2023 |
| Atlion Games Ltd | Wholesale & retail | 2026 |
| Atomic Talent Ltd | Administrative & support | 2023 |
| ATT Capital Limited | Construction | 2024 |
| AU Interiors Ltd | Construction | 2026 |
| Auto Garage Limited | Wholesale & retail | 2015 |
| Automaster (South Wales) Limited | Wholesale & retail | 2003 |
| Automotive (South Wales) Ltd | Extraterritorial | 2011 |
| Autospray Paint Supplies Limited | Wholesale & retail | 2014 |
| Avanti Change Ltd | Professional & scientific | 2025 |
| Azzurro Sky Limited | Information & communication | 2011 |
| B D Gurner Holdings Ltd | Financial services | 2023 |
| B&J Topshop Ltd | Wholesale & retail | 2024 |
| Backstedt Sports Ltd | Wholesale & retail | 2014 |
| Badger Property & Investment Limited | Real estate | 2024 |
| Barbacoa Bar and Tapas Ltd | Hospitality | 2025 |
| Bargain Blinds (Wales and South West) Limited | Manufacturing | 2013 |
| Bark Hotel Ltd | Extraterritorial | 2022 |
| Barrington Investments Limited | Professional & scientific | 2005 |
| Bartlett Technologies Limited | Information & communication | 2014 |
| BAV Logistics Ltd | Wholesale & retail | 2022 |
| Beef IT UP Ltd | Hospitality | 2021 |
| Behavioural Education Ltd | Education | 2019 |
| Bella Road Services Ltd | Transport & logistics | 2016 |
| Bella's Boutique Ltd | Other services | 2025 |