| 01211379 Limited | Wholesale & retail | 1975 |
| 11 Stanhope Road Limited | Households | 2003 |
| 2GAM Cyfyngedig | Information & communication | 2004 |
| 6 Clement Avenue Management Limited | Households | 2004 |
| A Jones Civil Engineering Limited | Construction | 2013 |
| A.W. Engineering (Darwen) Limited | Manufacturing | 2002 |
| Aberconwy Towbars and Trailers Limited | Wholesale & retail | 1996 |
| Abermaw GAS Heating Ltd. | Construction | 2003 |
| Abersoch & District Trade & Tourism Limited | Other services | 1995 |
| Abersoch Boatyard Limited | Wholesale & retail | 1973 |
| Agau Limited | Professional & scientific | 2007 |
| Allwedd Ltd | Professional & scientific | 2007 |
| Alpineering Ltd | Manufacturing | 2013 |
| Amcen Felinheli CYF | Construction | 2011 |
| Amison Associates Limited | Administrative & support | 2002 |
| Anderson Tree Specialists Limited | Agriculture & fishing | 2006 |
| Anglesey Caterers Limited | Real estate | 1959 |
| Antur Waunfawr | Manufacturing | 1984 |
| April Court Management Company Limited | Hospitality | 1995 |
| Arfon Rewinds Limited | Manufacturing | 2000 |
| Arfon Roberts A'I Gwmni Cyfyngedig | Wholesale & retail | 2004 |
| Arthur M. Harrisson Limited | Administrative & support | 2010 |
| Arvonia Coaches Ltd. | Administrative & support | 1992 |
| Atkin Groundworks Ltd | Construction | 2006 |
| Autosales Systems Ltd | Information & communication | 2005 |
| Awakened Development Ltd | Information & communication | 2021 |
| Awen Meirion Cyfyngedig | Wholesale & retail | 1972 |
| Aykroyd & Sons Limited | Wholesale & retail | 1932 |
| B. Jones & Sons Limited | Construction | 2006 |
| Bailey Telecommunications Limited | Information & communication | 2020 |
| Baileys and Partners Service Company LLP | | 2014 |
| Bala & District Motor Club Limited | Arts & recreation | 1992 |
| Bala Event Management Ltd | Hospitality | 2022 |
| Ballymurphy Films Ltd | Administrative & support | 2017 |
| Beardmore & Co Ltd | Financial services | 2001 |
| Beatons Accountants Limited | Professional & scientific | 1998 |
| Beaumaris Legion Ltd | Households | 2007 |
| Bengalheritage Cats Limited | Agriculture & fishing | 2019 |
| Berry Limited | Wholesale & retail | 1991 |
| Blue Lobster IT Limited | Information & communication | 2009 |
| Body Talk Limited | Other services | 2003 |
| Bookry Ltd | Information & communication | 2007 |
| Brandified Ltd | Information & communication | 2015 |
| Bridge Consultants (MON) Limited | Professional & scientific | 2007 |
| Broadwater Training Limited | Professional & scientific | 2002 |
| Bryn Gellyg CYF | Information & communication | 2007 |
| Bryn Jones Property Services Ltd | Households | 2006 |
| Bryn Marl Limited | Health & social care | 2004 |
| Bryn Meddyg Care Home Ltd | Health & social care | 2006 |
| Bryncir Garden Centre Ltd | Wholesale & retail | 2011 |
| C & B Solutions Ltd | Transport & logistics | 2024 |
| C Davies NON Ferrous Metals Ltd | Wholesale & retail | 2005 |
| Cadfan Refurbs Ltd | Transport & logistics | 2024 |
| Cadfans of Tywyn Limited | Wholesale & retail | 2019 |
| Cambrian Cleaners Limited | Other services | 1954 |
| Caroline Mondo Cleaning Services Ltd | Other services | 2004 |
| Cartrefi CCS Homes Ltd | Real estate | 2025 |
| Cheese on Post Ltd | Wholesale & retail | 2006 |
| Chilli Masala of Menai Bridge Ltd | Hospitality | 2024 |
| Clarke Building Design Limited | | 1982 |
| Classic Cabs Ltd | Administrative & support | 1999 |
| Clebran (Bangor) Limited | Health & social care | 1998 |
| Clebran Day Nursery Ltd | Health & social care | 2006 |
| Cloth World Limited | Wholesale & retail | 1991 |
| Clwb Chwareuon Madog CYF. | Arts & recreation | 1994 |
| Clwb Enfys (Llanfairfechan) Ltd | Health & social care | 2006 |
| Coronet Holidays Ltd | Hospitality | 1948 |
| Criccieth Holidays Ltd | Hospitality | 2022 |
| Cross Foxes Limited | Real estate | 1955 |
| Cwmni Rheoli Bro’R Awen CYF. | Households | 2017 |
| Cwmni TAN Llyn Fire Protection CYF | Administrative & support | 2006 |
| D Hogan Consulting Ltd | Administrative & support | 2025 |
| D Powys Davies Limited | Wholesale & retail | 2012 |
| Danline International Limited | Manufacturing | 1973 |
| David Meredith & Sons Limited | Mining & quarrying | 2003 |
| David Nash Sculpture Limited | Arts & recreation | 2007 |
| David Pritchard Properties Limited | Real estate | 1997 |
| Dickies Marine Services Limited | Manufacturing | 2013 |
| Dioni Self Catering Limited | Hospitality | 2010 |
| DK Scaffolding Wales Limited | Construction | 2013 |
| DOB Electrical (Contractors) Limited | Wholesale & retail | 2004 |
| Dobson Owen CYF. | Professional & scientific | 1999 |
| Dragonfire Mining Limited | Administrative & support | 2017 |
| Dros Y DWR Ltd | Hospitality | 2021 |
| DWJ Commercials Ltd | Manufacturing | 2007 |
| Dwyros CYF | Hospitality | 2020 |
| Dyffryn Seaside Estate Company Limited | Hospitality | 1960 |
| Dyfi Yard Repairs Limited | Wholesale & retail | 2005 |
| E W & W Roberts Limited | Construction | 2007 |
| E.D. Griffiths (Plant Hire & Sales) Limited | | 1984 |
| Eagle Airfield Equipment Limited | Manufacturing | 1970 |
| Egnitest Limited | Professional & scientific | 2006 |
| Eiddo LCP Properties Ltd | Real estate | 2025 |
| Eisteddfa Fisheries Limited | Agriculture & fishing | 2001 |
| Engineering Archaeological Services Limited | Professional & scientific | 1993 |
| Eureca Research Limited | Information & communication | 2004 |
| Fach Properties Limited | Agriculture & fishing | 1962 |
| Ffestiniog Railway Society | Other services | 1954 |
| FHH NO.1 Limited | Professional & scientific | 2003 |
| Firmhelm Limited | Manufacturing | 1977 |