| 'Dio'N Plesio? CYF | Extraterritorial | 2003 |
| 18 West END Parade Management Company Limited | Real estate | 2007 |
| 20 Westend Parade (Management) Limited | Extraterritorial | 2016 |
| 3E Smart Control Ltd | Construction | 2006 |
| 7I Insights Ltd | Professional & scientific | 2023 |
| A Lloyd Construction Ltd | Construction | 2020 |
| A Star Barbers Pwllheli Ltd | Other services | 2022 |
| A&A Properties & Construction Ltd | Construction | 2024 |
| AA Properties & Accommodation Ltd | Real estate | 2025 |
| AB Owain Properties CYF | Real estate | 2023 |
| Abererch Sands Holiday Centre Limited | Hospitality | 1967 |
| Abersoch Apparel Limited | Wholesale & retail | 2026 |
| Abersoch Beach Cafe & Shop Limited | Hospitality | 2013 |
| Abersoch Boardrider Limited | Wholesale & retail | 2003 |
| Abersoch Boat Works Limited | Manufacturing | 2023 |
| Abersoch Brewing Company Ltd | Manufacturing | 2022 |
| Abersoch Coffee Company Limited | Manufacturing | 2024 |
| Abersoch Deli Limited | Wholesale & retail | 2010 |
| Abersoch Dental Care Limited | Health & social care | 2010 |
| Abersoch Hire Ltd | Administrative & support | 2019 |
| Abersoch Marine and Charter Limited | Manufacturing | 2018 |
| Abersoch Moorings Limited | Agriculture & fishing | 2005 |
| Abersoch Sailing School Ltd | Wholesale & retail | 2012 |
| Abersoft Technology Limited | Professional & scientific | 2026 |
| Acoia CYF | Manufacturing | 2021 |
| Adeiladwaith Richard Williams Construction Ltd | Construction | 2025 |
| Adeiladwr GJ Builder Ltd | Construction | 2019 |
| Adeiladwyr Nefyn Builders CYF. | Construction | 2024 |
| Adeiladwyr North Wales Builders Ltd | Construction | 2024 |
| Adventures PER Mare Limited | Wholesale & retail | 2023 |
| Aesthetica North Wales Ltd | Other services | 2025 |
| AJ Swift Ltd | Wholesale & retail | 2019 |
| Albert Holiday Lettings CYF | Hospitality | 2020 |
| Alwyn Roberts Electricians Limited | Construction | 2016 |
| Amanda Williams (Pwllheli) Limited | Construction | 2015 |
| Anno's Africa Limited | Arts & recreation | 2009 |
| AP Prentis CYF | Administrative & support | 2019 |
| AR Jones Electrical Limited | Energy | 2013 |
| ARA Cabins Limited | Hospitality | 2022 |
| Arfon Hughes Limited | Professional & scientific | 2003 |
| ARTISAN7 Ltd | Real estate | 2015 |
| Arvonia Fish and Chips Limited | Hospitality | 2013 |
| Arwel Holiday Cottage Limited | Real estate | 2024 |
| Arwel W Williams CYF | Construction | 2012 |
| Attractions of Snowdonia | Professional & scientific | 2011 |
| Aviso Ltd | Professional & scientific | 2022 |
| Aztechs Limited | Information & communication | 2009 |
| B J Marine (U.K.) Ltd | Wholesale & retail | 2014 |
| B. Gaskell (Footwear) Limited | Wholesale & retail | 1959 |
| Bachellaeth CYF | Agriculture & fishing | 2026 |
| Bacstal PAC | | 2015 |
| Bacstal Partners Limited | Information & communication | 2002 |
| Bailey Wallace Ltd | Hospitality | 2026 |
| Balcony Solutions Ltd | Construction | 2018 |
| Bara Beru Byth Limited | Financial services | 2024 |
| Barber O1NE Ltd | Other services | 2024 |
| Barmouth Food Court Limited | Hospitality | 2023 |
| Beach View Abersoch Ltd | Hospitality | 2016 |
| Becws Glanrhyd CYF | Manufacturing | 2023 |
| Becws Islyn Aberdaron CYF | Manufacturing | 2024 |
| Becws Islyn Bakery Ltd | Manufacturing | 2012 |
| Becws Islyn Pwllheli CYF | Manufacturing | 2024 |
| BEE Property Services Ltd | Administrative & support | 2022 |
| Beeline Holiday Lets Limited | Real estate | 2019 |
| Bellfeast Limited | Households | 1978 |
| Bespoke Joinery North Wales Limited | Construction | 2012 |
| Big Game Hospitality Ltd | Hospitality | 2025 |
| Bluewater Marine ( North Wales) Ltd | Manufacturing | 2012 |
| Bluewater Marine Management Ltd | Professional & scientific | 2012 |
| BOB Jones Windows Technician Limited | Administrative & support | 2003 |
| Bodvel Hall CNC Ltd | Hospitality | 2022 |
| Bolmynydd CYF | Hospitality | 2021 |
| Bombay Joes Limited | Hospitality | 2025 |
| Bombay Joes Restaurant Ltd | Hospitality | 2025 |
| Booths Cleaning Services Limited | Administrative & support | 2010 |
| Brainsby Promotions Limited | Hospitality | 2023 |
| Brighter Futures Partnership Limited | Information & communication | 2000 |
| Bron Fedw Hydro Scheme Limited | Energy | 2005 |
| Brook Cottage Holidays Limited | Hospitality | 2020 |
| Brook Cottage Shepherd Huts Ltd | Hospitality | 2025 |
| Bryn Hafan Management Company Limited | Administrative & support | 2004 |
| Bryn Helyg Limited | Agriculture & fishing | 2020 |
| Bryn Noddfa CYF. | Hospitality | 2019 |
| Bryn Villa Farm Ltd | Extraterritorial | 2016 |
| Bull Bay Leisure Limited | Hospitality | 2025 |
| BWM Estates Limited | Administrative & support | 2015 |
| Bwydydd Madryn Foods CYF | Wholesale & retail | 2012 |
| Bythynod Bronmiod Ltd | Real estate | 2023 |
| C Evans Electrical Ltd | Construction | 2011 |
| C&L Breaks Limited | Hospitality | 2026 |
| C.S & G Ltd | Construction | 2006 |
| CAD Utilities Diversions Ltd | Professional & scientific | 2025 |
| Cadarn CYF | Professional & scientific | 2016 |
| Cadernid Construction CYF | Construction | 2024 |
| CAE Capel CYF | Construction | 2021 |
| Caepen Limited | Energy | 2015 |
| Caffi Largo CYF | Hospitality | 2015 |
| Caffi Siop Plas CYF | Hospitality | 2025 |
| Calibra Engineering Ltd. | Professional & scientific | 2016 |
| Cambrian Software (UK) Limited | Information & communication | 1994 |