| Higgins Building Supplies Ltd | Extraterritorial | 1991 |
| Higgins Holdings Limited | Extraterritorial | 1991 |
| Higgins Landscape & Garden Centre Limited | Extraterritorial | 2012 |
| Higgins Trade Supplies Limited | Financial services | 2021 |
| HJL Trading Ltd | Wholesale & retail | 1999 |
| Holidays in Wales Limited | Real estate | 1979 |
| Holyhead Bidco Limited | Financial services | 2018 |
| Holyhead Midco 1 Limited | Financial services | 2018 |
| Holyhead Midco 2 Limited | Financial services | 2018 |
| Holyhead Topco Limited | Financial services | 2018 |
| Holyhead Truck Services Ltd | Wholesale & retail | 2016 |
| Home Care Wales (Anglesey) Limited | Health & social care | 2018 |
| HPF Group Limited | Wholesale & retail | 2025 |
| Hughes Group Construction Ltd | Construction | 2023 |
| Huws Gray Limited | Wholesale & retail | 1990 |
| Ice Bath Hub Ltd | Wholesale & retail | 2023 |
| Ideal Kitchens (Anglesey) Limited | Manufacturing | 2010 |
| Intelligent Ocean Ltd | Education | 2011 |
| Jalsa Llangefni Ltd | Hospitality | 2025 |
| Jamie Jones Limited | Wholesale & retail | 2021 |
| JC Tanning Ltd | Other services | 2026 |
| JLG Installations Limited | Construction | 2022 |
| Jones-Evans Consulting Ltd | Education | 2022 |
| K F Supplies Limited | Extraterritorial | 2013 |
| KC Auto Sales Ltd | Extraterritorial | 2019 |
| Kenrose Residential Limited | Real estate | 2024 |
| Killerby Lease Limited | Administrative & support | 1981 |
| Koseoglu Barber Shop Ltd | Other services | 2024 |
| LA Belle Rosè O’Neill Ltd | Other services | 2023 |
| LA Optical Limited | Manufacturing | 2012 |
| LAN Cleaning Services Limited | Administrative & support | 2026 |
| LD Landscaping and Carpentry Ltd | Transport & logistics | 2025 |
| LEE & Pryde Ltd | Hospitality | 2024 |
| Legal-Island 1998 Limited | Extraterritorial | 1998 |
| Lina CAFE1 Ltd | Hospitality | 2025 |
| Llangefni Chiropractic Clinic Ltd | Health & social care | 2015 |
| Llangefni Social Enterprise | Professional & scientific | 2013 |
| Llangefni Star Fryer Ltd | Hospitality | 2024 |
| Llangefni Town Football Club | Arts & recreation | 2020 |
| London and Anglesey Property Company Limited | Real estate | 1995 |
| Lucas OIL Products UK Limited | Manufacturing | 2001 |
| Macros Fuel Bar Ltd | Hospitality | 2025 |
| Macventure Play Co Limited | Construction | 2007 |
| Magallanes Cymru Tidal Energy Limited | Professional & scientific | 2023 |
| Mangor Shop Limited | Wholesale & retail | 2025 |
| Marquess Masonry Ltd | Manufacturing | 2017 |
| Medic 1 Direct Ltd | Health & social care | 2010 |
| Medra (Ccts) Limited | Education | 2004 |
| Medrwn MON | Other services | 2001 |
| Melin Llynon CYF | Hospitality | 2021 |
| Menter MON CYF | Administrative & support | 1996 |
| Menter MON Hydrogen Limited | Manufacturing | 2022 |
| Menter MON Morlais Holdings Limited | Financial services | 2022 |
| Menter MON Solar Limited | Other services | 2026 |
| Menter MÔN Morlais Limited | Real estate | 2017 |
| Midoo Exploring Limited | Wholesale & retail | 2025 |
| Milford Limited | Extraterritorial | 1974 |
| MMO Offshore Consulting Ltd | Professional & scientific | 2018 |
| Moduron MON CYF | Wholesale & retail | 2012 |
| MON Active Limited | Education | 2013 |
| MON MIX CYF | Manufacturing | 2023 |
| MON Safety Group Ltd | Education | 2024 |
| Mona Lifting Limited | Manufacturing | 2004 |
| Mona Tractor Company Limited | Wholesale & retail | 1981 |
| More Than Bags Ltd | Wholesale & retail | 2013 |
| Morgeisi Copa Mortgages Ltd | Financial services | 2023 |
| MR Holt's Ltd | Manufacturing | 2021 |
| Nelson Hughes Construction Ltd | Construction | 2019 |
| NJW Training and Consultancy Ltd | Education | 2018 |
| North Wales Recycle I.T. CIC | Water & waste | 2019 |
| North Wales Roofing Limited | Construction | 2020 |
| NPB 33 Ltd | Hospitality | 2024 |
| NRD Specialist Physiotherapy Ltd | Health & social care | 2024 |
| NU YOU Beauty Limited | Other services | 2019 |
| O'Connor Housekeeping Limited | Administrative & support | 2022 |
| ON Point Tanning Beauty and Fitness Limited | Other services | 2021 |
| Oshel Group Limited | Real estate | 2024 |
| Owens Building & Roofing Limited | Construction | 2013 |
| Parc Bach Limited | Wholesale & retail | 2020 |
| Parry Davies Clwyd-Jones & Lloyd LLP | | 2012 |
| Patagonia Bidco Limited | Financial services | 2021 |
| Patagonia Holdco 3 Limited | Financial services | 2021 |
| Patagonia Holdco 4 Limited | Financial services | 2021 |
| Paul Parry A'I FAB CYF | Construction | 2010 |
| Paxcorn Ltd | Extraterritorial | 2003 |
| Peat DAM Limited | Financial services | 2022 |
| Peel Street Properties NW Ltd | Real estate | 2022 |
| Pezaria Airlines Ltd | Hospitality | 2026 |
| Physio MÔN Limited | Other services | 2023 |
| Plas Llanfihangel CYF | Agriculture & fishing | 2015 |
| Plas Milk Limited | Agriculture & fishing | 2022 |
| Popty Pizza Ltd | Hospitality | 2019 |
| Premier Developments (NW) Ltd | Construction | 2019 |
| Qualplas Limited | Manufacturing | 1987 |
| R & J Hughes and SON Ltd | Other services | 2019 |
| R Seddon Commercial Holdings Ltd | Real estate | 2026 |
| Rachel Marie Mortgage Services Limited | Financial services | 2017 |
| Raven Oak Security and Risk Consultancy Ltd | Information & communication | 2025 |
| Red Dragon K9 Limited | Administrative & support | 2019 |
| Rhosneigr Property Lettings Ltd | Real estate | 2015 |