| 2 Tone (Anglesey) Limited | Wholesale & retail | 2010 |
| 2MJB Limited | Real estate | 2015 |
| 42ABLE Limited | Information & communication | 2024 |
| A & R Tyres CYF | Manufacturing | 2024 |
| A Better Way Counselling Service Ltd | Health & social care | 2025 |
| A.B. Jetwash Ltd | Administrative & support | 2025 |
| A55 Safety Training Limited | Education | 2024 |
| Adpeak Ltd | Information & communication | 2026 |
| Alflo Productions Limited | Information & communication | 2023 |
| Anglesey Aggregates Holdings Ltd | Financial services | 2025 |
| Anglesey Aggregates Ltd | Administrative & support | 2016 |
| Anglesey Central Railway Limited | Arts & recreation | 2007 |
| Anglesey Commercial Spares Ltd | Wholesale & retail | 2010 |
| Anglesey Contracting Ltd | Construction | 2014 |
| Anglesey Getaways Ltd | Other services | 2018 |
| Anglesey Laundry Ltd | Other services | 2025 |
| Anglesey Lifestyle Homes Limited | Construction | 2016 |
| Anglesey Locums Limited | Health & social care | 2011 |
| Anglesey OIL Limited | Energy | 1982 |
| Anglesey Properties Management Co. Ltd. | Real estate | 1993 |
| Anglesey Riding Centre Limited | Arts & recreation | 2010 |
| Anglesey RUM Co Ltd | Manufacturing | 2021 |
| Anglesey Safety Training Limited | Education | 2020 |
| Anglesey Vineyard Ltd | Manufacturing | 2025 |
| Animal Allies Limited | Information & communication | 2024 |
| Ar-Fon Windows Limited | Construction | 2015 |
| Arfon Roofing Limited | Construction | 2020 |
| Arwyddion Caernarfon Signs Limited | Manufacturing | 2016 |
| Astar Partners Ltd | Real estate | 2017 |
| Atlasapollo Limited | Information & communication | 2025 |
| Avilastar Limited | Information & communication | 2022 |
| Awen Oncology Limited | Professional & scientific | 2021 |
| B & D Jones Holdings Limited | Professional & scientific | 2010 |
| B & D Jones Limited | Real estate | 2010 |
| Baileys and Partners Holdings Limited | Financial services | 2025 |
| Baram African Foods and Drinks Ltd | Manufacturing | 2025 |
| Base-Lab Health CIC | Professional & scientific | 2019 |
| Becws MON Bakery Limited | Manufacturing | 2016 |
| Bekae Holding Limited | Construction | 2017 |
| Beyond Thought Ltd | Information & communication | 2024 |
| BIC Innovation Ltd | Professional & scientific | 2004 |
| Bragdy Mona CYF | Manufacturing | 2018 |
| Bridges Garage Pentraeth Ltd | Wholesale & retail | 2018 |
| Brighter Behind the Clouds Limited | Administrative & support | 2023 |
| Britannia Renewables Limited | Construction | 2022 |
| Bryn DU Broncos Limited | Hospitality | 2025 |
| Butterfly Menai Bridge Ltd | Wholesale & retail | 2014 |
| BWJ Engineering Ltd | Professional & scientific | 2022 |
| Caernarfon Signs Limited | Professional & scientific | 2023 |
| Canolfan Arwerthiant Bryncir CYF | Wholesale & retail | 2001 |
| Capricorn Ventis Limited | Information & communication | 2009 |
| Catref Cariad Ltd | Health & social care | 2023 |
| Chapel Street Takeaway Ltd | Hospitality | 2018 |
| Chwaral Goch Limited | Households | 2025 |
| Clear Accounting Limited | Professional & scientific | 2013 |
| Clear Mobitel Ltd | Information & communication | 2009 |
| Coffi DRE Coffee Ltd | Wholesale & retail | 2024 |
| Coffi DRE Events Limited | Hospitality | 2024 |
| Creadigol Design Ltd | Professional & scientific | 2022 |
| Creutech Ltd | Information & communication | 2024 |
| Cybi Building Plastics Limited | Wholesale & retail | 2003 |
| Cybi Planning Ltd | Professional & scientific | 2022 |
| Cybi Plastics Limited | Extraterritorial | 2003 |
| Cybi Property Ltd | Real estate | 2022 |
| Cymru LAN Cyfyngedig | Water & waste | 2002 |
| Cymru LAN Holdings Limited | Financial services | 2018 |
| D G Williams Builders Limited | Construction | 2020 |
| D J Medical Services Limited | Health & social care | 2001 |
| Dark Matter Detailing Ltd | Administrative & support | 2023 |
| Data for Good Ltd | Extraterritorial | 2016 |
| Delilah Developments Ltd | Real estate | 2005 |
| Dogma UK Films Limited | Information & communication | 2019 |
| DPI Consulting Limited | Information & communication | 2016 |
| Dragon Independent School Manchester Ltd | Education | 2024 |
| Drinking Buddies Ltd | Professional & scientific | 2018 |
| DRN Recruitment Limited | Administrative & support | 2020 |
| Drydogs Limited | Manufacturing | 2023 |
| E & D Thomas Ltd | Construction | 2024 |
| Ecodetect Limited | Information & communication | 2024 |
| Eden Restored Limited | Administrative & support | 2012 |
| Egin Cyfyngedig | Professional & scientific | 1992 |
| Ella Jane Limited | Hospitality | 2013 |
| Energy for Good Limited | Professional & scientific | 2017 |
| Episteme Science Limited | Professional & scientific | 2015 |
| Eryri Bookkeeping Ltd | Professional & scientific | 2026 |
| Esargi Limited | Manufacturing | 2008 |
| Escort Power Ltd | Wholesale & retail | 2018 |
| Evergreen Architects Ltd | Professional & scientific | 2018 |
| Exacap Ltd. | Information & communication | 2025 |
| Exadev Ltd. | Information & communication | 2013 |
| Exagroup Holdings Ltd. | Financial services | 2025 |
| Exosec Limited | Information & communication | 2018 |
| Fit Fanny Adams Ltd | Health & social care | 2021 |
| Foodsheducation MÔN C.I.C. | Education | 2026 |
| G D Jones and SON Ltd | Wholesale & retail | 2009 |
| G D Jones Fuel Oils Ltd | Wholesale & retail | 2015 |
| G1 Building & Roofing Ltd | Construction | 2025 |
| GLU Systems Limited | Information & communication | 2021 |
| Gozeto Ltd | Other services | 2020 |
| Green Scaffolding Group Ltd | Construction | 2023 |