| Gwasanaethau Bleeper CYF. | Financial services | 2024 |
| Gwenallt Consulting Limited | Professional & scientific | 2014 |
| HCS Plumbing and Heating Supplies Limited | Wholesale & retail | 2004 |
| Hiraeth Group Ltd | Hospitality | 2018 |
| Holidays Anglesey Ltd | Hospitality | 2025 |
| Holland Arms Hotel Limited | Hospitality | 2026 |
| Home House Solutions NW Ltd | Real estate | 2023 |
| HUW Elis Owen & Co Limited | Real estate | 2024 |
| Hvac Climate Solutions Ltd | Construction | 2023 |
| Hydrowing Limited | Professional & scientific | 2017 |
| Hydrowing Tidal Projects 2 Ltd | Professional & scientific | 2024 |
| Hydrowing Tidal Projects Limited | Energy | 2022 |
| International Aqua-Tech Limited | Construction | 1992 |
| Inventive Properties (Cymru) Ltd | Real estate | 2017 |
| IP Tax Solutions Ltd | Professional & scientific | 2013 |
| J B By-Products Limited | Wholesale & retail | 2021 |
| JB Safe-T Consultancy Limited | Other services | 2021 |
| Jesse James Bunkhouse Ltd | Hospitality | 2022 |
| JNF Clothing Ltd | Wholesale & retail | 2025 |
| JNF Property Services Ltd | Construction | 2026 |
| JNJ Property Development Ltd | Construction | 2024 |
| John Kelly Homes Ltd | Construction | 2013 |
| Jreg Developments Ltd | Construction | 2024 |
| KEV Jones Engineering Services Ltd | Water & waste | 2025 |
| KIT LOG Ltd | Information & communication | 2013 |
| Larda Food & Beverages Ltd | Hospitality | 2026 |
| Learning 2 BEE Ltd | Education | 2024 |
| Lloyd Williams a Hughes CYF | Wholesale & retail | 2001 |
| LMS Surfacing Ltd | Construction | 2018 |
| Lode Systems Ltd | Information & communication | 2026 |
| Loft Solutions NW Ltd | Construction | 2018 |
| LOG on Fires Limited | Wholesale & retail | 2009 |
| Loyalty Logistix Limited | Information & communication | 2003 |
| M & G Windows Ynys MON Limited | Construction | 1993 |
| Madmen Corporation Limited | Information & communication | 2009 |
| Mark Morris Flooring Limited | Construction | 2017 |
| Menai Group Limited | Real estate | 2024 |
| Menai Solar Limited | Construction | 2018 |
| Metex Ltd | Wholesale & retail | 2014 |
| MG Securical Limited | Administrative & support | 2022 |
| MGC Ynys MON Limited | Professional & scientific | 2009 |
| MOR Energy Limited | Construction | 2022 |
| MR V a Mcclelland Ltd | Extraterritorial | 2025 |
| Muriau Ltd | Real estate | 2026 |
| Mynde Ltd | Administrative & support | 2022 |
| Naturiol Bangor Ltd | Professional & scientific | 2007 |
| NET Facilities Limited | Construction | 2023 |
| NEU Water Limited | Manufacturing | 2017 |
| Nextgen Business Solutions Ltd | Professional & scientific | 2023 |
| Nordisk Innovation Limited | Wholesale & retail | 2025 |
| NW Drainage Solutions Ltd | Water & waste | 2018 |
| Olew MON CYF | Professional & scientific | 2006 |
| Outline Building Solutions CYF | Professional & scientific | 2018 |
| Oyster Holiday Cottages Ltd | Hospitality | 2023 |
| Paws Aloud Ltd | Wholesale & retail | 2022 |
| PB Management Ltd | Professional & scientific | 2025 |
| Peirianneg IE Engineering Limited | Professional & scientific | 2021 |
| Pelly Group Ltd | Information & communication | 2023 |
| Pelly Systems Ltd | Information & communication | 2023 |
| Plas Berw Limited | Real estate | 2025 |
| PNR Electrical Limited | Construction | 2023 |
| Popeth Pilates Limited | Education | 2016 |
| Premier Welding and Tool Supplies Limited | Manufacturing | 2014 |
| Pro GRP Roofing Ltd | Construction | 2020 |
| Proxymus Limited | Information & communication | 2001 |
| Q-Vet Ltd | Wholesale & retail | 2015 |
| Resolution Drones Limited | Professional & scientific | 2025 |
| Round Electrical Distribution Ltd | Wholesale & retail | 2008 |
| S D (Newborough) Ltd | Real estate | 2004 |
| S H R Contracting Ltd | Construction | 2025 |
| Sanderling Property Limited | Real estate | 2013 |
| Sangoma Energy Projects Limited | Financial services | 2025 |
| Seaqurrent Energy Wales Ltd | Energy | 2025 |
| Slhh Property SPV01 Ltd | Real estate | 2024 |
| Sparkle and Shine Anglesey Limited | Administrative & support | 2023 |
| Sparkle and Shine Holiday Management Anglesey Limited | Administrative & support | 2023 |
| Straits Homes Limited | Real estate | 2021 |
| SWN Y Fraint Management Company Ltd | Households | 2016 |
| Synargize Ltd | Information & communication | 2023 |
| Talent Pathway ID Ltd | Professional & scientific | 2021 |
| Techvis Limited | Information & communication | 2024 |
| Tecwila Ltd | Wholesale & retail | 2025 |
| Tegridy 1000 Limited | Information & communication | 2018 |
| Tegridy 1100 Limited | Information & communication | 2018 |
| Tegridy 1200 Limited | Information & communication | 2018 |
| Tegridy 600 Limited | Extraterritorial | 2023 |
| Tegridy 800 Limited | Extraterritorial | 2025 |
| Tegridy 900 Limited | Information & communication | 2019 |
| Tegridy Ventures Limited | Professional & scientific | 2020 |
| THE Carnan Workshop Limited | Manufacturing | 2015 |
| THE Drop Couriers Ltd | Wholesale & retail | 2025 |
| THE Hashtag Services Ltd | Information & communication | 2024 |
| THE Pelvic Physios Limited | Health & social care | 2022 |
| THE Photographic Adventure Company Ltd | Administrative & support | 2023 |
| THE Willows Anglesey Ltd | Agriculture & fishing | 2025 |
| Thomas and Sons Roofing Contractors Ltd | Construction | 2023 |
| Thorne Rope Access Solutions Ltd | Other services | 2018 |
| Tony Olley Construction Ltd | Construction | 2015 |
| Trigolion Llanddaniel FAB | Other services | 1995 |
| Trocymru CYF | Professional & scientific | 2025 |