| ALL Seasons Healthcare Ltd | Health & social care | 2024 |
| ALL Wales Cleaning Solutions Ltd | Administrative & support | 2025 |
| Alltwen Farm Limited | Agriculture & fishing | 2025 |
| Allweddi Morgans Ltd | Real estate | 2020 |
| Alous Care Limited | Health & social care | 2022 |
| ALP Property Management Ltd. | Real estate | 2002 |
| Alpenglow Candles Ltd | Wholesale & retail | 2023 |
| ALS Cleaning Services Ltd | Administrative & support | 2016 |
| Altavale Japan Ltd | Professional & scientific | 2024 |
| Alwen Equine and Livestock Nutrition Limited | Agriculture & fishing | 2021 |
| AM DRO Consulting and Events Ltd | Professional & scientific | 2022 |
| Amlwg Limited | Agriculture & fishing | 1988 |
| Amped PCR Ltd | Professional & scientific | 2022 |
| Amric Limited | Hospitality | 2004 |
| Anatalya Foods Limited | Hospitality | 2024 |
| Anchoress Musings Group Ltd | Health & social care | 2020 |
| Andker Ltd | Arts & recreation | 2014 |
| Andres Place Limited | Hospitality | 2024 |
| Ani-Bendod Ltd | Wholesale & retail | 2021 |
| Animals in Need (WLS) Limited | Wholesale & retail | 2010 |
| Annals of Botany Company | Information & communication | 1903 |
| Annwn Marketing Limited | Professional & scientific | 2026 |
| Annwyl Properties Limited | Real estate | 2018 |
| Anthony Motors Limited | Wholesale & retail | 1979 |
| Aquarius Asset Management Ltd | Real estate | 2026 |
| Arbcore Ltd. | Agriculture & fishing | 2012 |
| Arbmech Ltd | Administrative & support | 2018 |
| Arcitekbio Ltd | Professional & scientific | 2018 |
| Arfc Commercial Limited | Hospitality | 2019 |
| ARI Pers UK Holdings Ltd | Financial services | 2026 |
| Aridma Property Doctors Ltd | Construction | 2024 |
| Art Body Mind Limited | Health & social care | 2022 |
| ASB Repairs Limited | Wholesale & retail | 2025 |
| Asil Catering Ltd | Hospitality | 2019 |
| ASJ Exterior Solutions Ltd | Administrative & support | 2026 |
| Atebol Cyfyngedig | Information & communication | 2003 |
| Auto Finance Limited | Other services | 2011 |
| Autocraft ARC Management Services Limited | Wholesale & retail | 2011 |
| AVE Developments Ltd | Construction | 2019 |
| AVE Properties Limited | Other services | 2015 |
| AW Accounting Limited | Professional & scientific | 2023 |
| AZA Aber Ltd | Hospitality | 2026 |
| B. C. Development Limited | Real estate | 1999 |
| B1 Barber Ltd | Other services | 2026 |
| Baba Jerk Ltd | Extraterritorial | 2020 |
| Baba Yummy Cafe Ltd | Hospitality | 2025 |
| Bakavathi Trading Ltd | Wholesale & retail | 2015 |
| Ballard Offshore Properties Ltd | Real estate | 2018 |
| Ballard Properties UK Limited | Real estate | 2009 |
| Banner Plumbing Limited | Construction | 2016 |
| Baravin Aberystwyth CYF | Hospitality | 2012 |
| Barbara & Betty Catering Ltd | Hospitality | 2026 |
| Battle Horse Ltd | Manufacturing | 2021 |
| Bay Wash Laundrette Ltd | Administrative & support | 2024 |
| BBF Vehicle Services Limited | Wholesale & retail | 2011 |
| BDW Consultancy Limited | Construction | 2013 |
| Beech Tree Lakes Ltd | Hospitality | 2019 |
| Being UK Ltd | Health & social care | 2022 |
| Belle VUE Aberystwyth Ltd | Hospitality | 2023 |
| Berner Management Consultants Ltd | Construction | 2018 |
| Berw Limited | Information & communication | 1988 |
| Best Self Storage Limited | Transport & logistics | 2025 |
| Beulah Sire Reference Co. Ltd. | Agriculture & fishing | 1997 |
| Bicton Construction Limited | | 1992 |
| Big Wave - TON Fawr CIC | Administrative & support | 2024 |
| Birchill Access Consultancy Ltd | Professional & scientific | 2014 |
| Blakemore & Co Ltd | Hospitality | 2008 |
| Bliss Scaffolding Ltd | Construction | 2017 |
| Blue Sky 7 Investments Ltd | Real estate | 2021 |
| Boca Properties Ltd | Real estate | 2018 |
| Boldridge Global Ltd | Administrative & support | 2025 |
| Borth and Ynyslas Golf Club (Trading) Limited | Arts & recreation | 2023 |
| Borth and Ynyslas Golf Club,Limited(The) | Arts & recreation | 1912 |
| Boswell Technical Services Ltd. | Professional & scientific | 2017 |
| Botanega Ltd | Agriculture & fishing | 2024 |
| Bragdy NI CYF | Manufacturing | 2023 |
| Bramblewood Rentals Limited | Administrative & support | 2025 |
| Breedon Management Limited | Information & communication | 2017 |
| Briallyn Ltd | Real estate | 2015 |
| Brian Roberts Building Limited | Construction | 2006 |
| Brightwires Ltd | Construction | 2025 |
| Brookglen Holdings Ltd | Construction | 2018 |
| Brookglen Systems Limited | Construction | 1996 |
| Bryn Eithin CYF | Real estate | 2008 |
| Brynderw Halls Limited | Real estate | 2021 |
| Brynrheidol Management Company Limited | Real estate | 2015 |
| Brynymor Management Company Limited | Real estate | 1987 |
| Building Controls Maintenance Holdings Limited | Construction | 2024 |
| BY Alana Limited | Manufacturing | 2015 |
| C C Aberystwyth Limited | Professional & scientific | 2017 |
| C J Holdings Limited | Real estate | 2022 |
| Cactws CYF | Wholesale & retail | 2016 |
| Cadence West CIC | Health & social care | 2025 |
| Cae'R Ysgol Management Limited | Households | 2016 |
| Caer Keys Ltd | Hospitality | 2013 |
| Caffi #27 Ltd | Hospitality | 2025 |
| Caffi Sgwar CYF | Hospitality | 2024 |
| Caffi Y Gornel CYF | Hospitality | 2023 |
| Calban's Limited | Real estate | 2025 |
| Calch a Chlai Limited | Construction | 2025 |