| 040423 Limited | Hospitality | 2023 |
| 08112018 Ltd | Hospitality | 2018 |
| 1-33 Llys Newydd RTM Company Ltd | Households | 2024 |
| 1111RECRUITMENT Ltd | Administrative & support | 2025 |
| 1111RECRUITMENTSOLUTIONS Ltd | Administrative & support | 2026 |
| 1ST Choice Transport Ltd | Transport & logistics | 2005 |
| 2 Sisters Property Ltd | Households | 2025 |
| 24.5 Degree Limited | Hospitality | 2025 |
| 25 Sport Ltd | Arts & recreation | 2025 |
| 271 Clinical Services Ltd | Health & social care | 2024 |
| 2J Homes Limited | Real estate | 2025 |
| 3 M'S Timberframe & Carpentry Limited | Construction | 2009 |
| 3035 Records Ltd | Wholesale & retail | 2025 |
| 360 Property & Lettings Group Ltd | Real estate | 2022 |
| 38 HBG Ltd | Real estate | 2025 |
| 3C Hill Management Limited | Households | 2014 |
| 3K'S Engineering Partners LLP | | 2022 |
| 3M'S Carpentry Limited | Manufacturing | 2023 |
| 420 DNA Trading Ltd | Wholesale & retail | 2020 |
| 44 Property Ltd | Real estate | 2025 |
| 4REAL Estate Limited | Real estate | 2023 |
| 4U Barber Shop Ltd | Other services | 2025 |
| 5JS Property Limited | Real estate | 2013 |
| 82 Commercial Street Limited | Real estate | 2017 |
| A & K Installations Limited | Manufacturing | 2017 |
| A & P Spuds Ltd | Wholesale & retail | 2015 |
| A and D Imaging Ltd | Professional & scientific | 2018 |
| A Clean Touch Ltd | Administrative & support | 2020 |
| A Flight to Remember Ltd | Other services | 2025 |
| A G Celak Limited | Transport & logistics | 2023 |
| A R Carpentry & Installations Limited | Manufacturing | 2022 |
| A R Jones Agricultural Services Ltd | Other services | 2023 |
| A to Z Insurance Services Ltd | Financial services | 2012 |
| A W L Digital Limited | Wholesale & retail | 2010 |
| A&Cda Ltd | Administrative & support | 2026 |
| A&M Contractors (Wales) Limited | Construction | 2005 |
| A&N Lifestyle Express Ltd | Wholesale & retail | 2020 |
| A-Z Electrical Install Limited | Construction | 2015 |
| A1 Interiors (SW) Limited | Construction | 2019 |
| A1 Recovery & Mechanical Ltd | Transport & logistics | 2026 |
| Abbey Driveways Llanelli Limited | Construction | 2024 |
| Abbey Masonry and Restoration Limited | Manufacturing | 2001 |
| Abbie Dodd Photography Ltd | Professional & scientific | 2025 |
| ABC Money Forex Ltd | Financial services | 2021 |
| ABC Money Ltd | Financial services | 2018 |
| Aberhealth Ltd | Health & social care | 2025 |
| Abertawe Engineering Services Ltd | Professional & scientific | 2010 |
| Abertawe Property Group Limited | Real estate | 2024 |
| Absolutemotocross Limited | Administrative & support | 2017 |
| Acacia People Partners Limited | Extraterritorial | 2023 |
| Access Autolocksmith Ltd | Administrative & support | 2021 |
| Acct Limited | Transport & logistics | 2018 |
| Ace Llanelli Limited | Hospitality | 2018 |
| Ace Swansea Limited | Hospitality | 2025 |
| Achddu Villa Ltd | Real estate | 2018 |
| Acmp UK Chapter Ltd | Other services | 2018 |
| Acop Group Limited | Education | 2008 |
| Acop Hire Limited | Extraterritorial | 2014 |
| Acorn 3000 Limited | Administrative & support | 2014 |
| Acorn Timber Craft Ltd | Manufacturing | 2023 |
| Across the NET Ltd | Information & communication | 2018 |
| Action Surveillance and Cctv Limited | Administrative & support | 2009 |
| Acumen Fire Protection Specialists (Afps) Ltd | Professional & scientific | 2019 |
| Adam YN YR Ardd CYF. | Manufacturing | 2020 |
| Adatrys AI Limited | Information & communication | 2025 |
| Adeilad Ltd | Real estate | 2015 |
| Adept GRP Enclosures Ltd | Other services | 2022 |
| Adepta Consulting Limited | Professional & scientific | 2023 |
| Adfeilion Ltd | Wholesale & retail | 2025 |
| Adfusion Limited | Professional & scientific | 2021 |
| Adnan Tikka House Ltd | Hospitality | 2025 |
| ADP Cleaning Services Ltd | Administrative & support | 2023 |
| ADS Rentals Ltd | Real estate | 2021 |
| ADU Ltd | Real estate | 2025 |
| Advanced AI Marketing Ltd | Information & communication | 2026 |
| Advanced Electronic Systems Limited | Manufacturing | 2004 |
| Advanture Enterprises Ltd | Wholesale & retail | 2024 |
| Aeon GB Limited | Construction | 2007 |
| Aesthetically Green Ltd | Other services | 2024 |
| Aesthetics Facial Cosmetics Ltd | Other services | 2025 |
| AF & Sons Property Ltd | Real estate | 2025 |
| AFA Works Ltd | Professional & scientific | 2025 |
| Affinity Flux Media Group Limited | Professional & scientific | 2018 |
| Agile Agenda Limited | Information & communication | 2023 |
| Agriview Ltd | Administrative & support | 2026 |
| AIL Gyfle-Second Chance Ltd | Manufacturing | 2015 |
| Ailcyfle C.I.C. | Hospitality | 2026 |
| Air Conditioning Swansea Limited | Energy | 2013 |
| AJ Ramsden Ltd | Professional & scientific | 2026 |
| AJ121 Ltd | Other services | 2026 |
| AJB Transport Limited | Transport & logistics | 2024 |
| Ajbp Ltd | Construction | 2018 |
| AJR Inns Limited | Hospitality | 2020 |
| AK Health & Life Ltd | Financial services | 2025 |
| AKM Technology Ltd | Professional & scientific | 2012 |
| AKS Dental Limited | Health & social care | 2022 |
| AL Morgan Properties Ltd | Real estate | 2025 |
| AL Salsa Limited | Arts & recreation | 2013 |
| Alana Bakes Ltd | Manufacturing | 2024 |
| ALC Mortgages Limited | Financial services | 2025 |