| Transport Cymru Consultancy Limited | Professional & scientific | 2019 |
| TRB Cornerstone Ltd | Real estate | 2026 |
| Tregantle AI Ltd | Information & communication | 2025 |
| Trinity Colwyn Bay Estate Limited | Real estate | 2024 |
| TRY Sport & Leisure CIC | Education | 2020 |
| TUDOR21 Limited | Professional & scientific | 2014 |
| Twigg Trading Limited | Wholesale & retail | 2011 |
| Ty'R Bont Management Company Limited | Households | 2023 |
| TYC Property Limited | Real estate | 2025 |
| Ubique Media Ltd | Professional & scientific | 2025 |
| UDS (North West) Limited | Extraterritorial | 2010 |
| UK Caravan Franchise Ltd | Wholesale & retail | 2013 |
| UK Caravans Direct Limited | Wholesale & retail | 2009 |
| UK Caravans Limited | Wholesale & retail | 2009 |
| UK Specialist Watches Limited | Wholesale & retail | 2013 |
| Uncommon Bloke Ltd | Arts & recreation | 2025 |
| Underground Artist Movement Ltd | Information & communication | 2024 |
| Uniserpaid Ltd | Professional & scientific | 2016 |
| Upper Colwyn Bay Community Centre Group Ltd | Arts & recreation | 1998 |
| Urban Loft Solutions Limited | Construction | 2024 |
| Valentis Cosmetics Ltd | Manufacturing | 2026 |
| Vardre Estates Ltd | Hospitality | 2026 |
| Vardre Management Company Limited | Real estate | 2000 |
| Variety One Extra Ltd | Wholesale & retail | 2018 |
| Veca Ltd | Arts & recreation | 2020 |
| Venue @ the Clock House Ltd | Hospitality | 2020 |
| Videoninja Media Limited | Information & communication | 2025 |
| Vintory Group Limited | Wholesale & retail | 2026 |
| Vintosa UK Ltd | Hospitality | 2026 |
| Vircap Consulting Limited | Professional & scientific | 2013 |
| Virgilio's Restaurant Ltd | Hospitality | 2015 |
| Vision Housing Solutions Ltd | Real estate | 2026 |
| Volt Air Marine Engineering Limited | Professional & scientific | 2017 |
| W&R URO Limited | Health & social care | 2026 |
| W&S Homes Ltd | Hospitality | 2021 |
| W.J.Roberts & Sons(Llandudno)Limited | Information & communication | 1956 |
| Walsh Commercial Properties Limited | Real estate | 2023 |
| Walsh Investment Holdings Limited | Financial services | 2025 |
| Walshaw Avenue Limited | Real estate | 2018 |
| Wang's M Ltd | Hospitality | 2017 |
| Ward & Jones Limited | Administrative & support | 2024 |
| Wards Gaming Ltd | Wholesale & retail | 2023 |
| Warehaus Signs Limited | Professional & scientific | 2021 |
| Warp 3D CYF | Manufacturing | 2025 |
| Warren Barns Management Company Limited | Households | 2026 |
| Warren Engineering Services Limited | Professional & scientific | 2007 |
| Warwyn Homes Ltd | Construction | 2022 |
| Water Supply Solutions Ltd | Water & waste | 2017 |
| WE ARE Nature Based CIC | Professional & scientific | 2024 |
| Welcome Group Limited | Professional & scientific | 2016 |
| Wellbeing Works Ltd | Health & social care | 2019 |
| Wellness Medical Aesthetics Ltd | Other services | 2025 |
| Welsh Centre for Action on Dependency and Addiction Ltd | Health & social care | 2001 |
| Wendy Alison Ltd | Real estate | 2025 |
| Wepm Ltd | Professional & scientific | 2018 |
| West END Dental Colwyn Bay Ltd | Health & social care | 2012 |
| West END Dental Holdings Ltd | Health & social care | 2007 |
| West END Dental Llangefni Ltd | Health & social care | 2015 |
| West END Dental Porthmadog Ltd | Health & social care | 2014 |
| West END Dental Prestatyn Limited | Health & social care | 2023 |
| West END Dental Wirral Limited | Health & social care | 2025 |
| West END Health Limited | Health & social care | 2025 |
| White Tower Salonika Ltd | Hospitality | 2026 |
| Whitfield Enterprises Limited | Information & communication | 2014 |
| Whohair Ltd | Other services | 2012 |
| Williams Capital Group Holdings Ltd | Financial services | 2025 |
| Williams Development Group Ltd | Construction | 2025 |
| Williams Digital Assets Ltd | Information & communication | 2025 |
| Williams Renewable Services Ltd | Manufacturing | 2023 |
| Williams Services Limited | Education | 2003 |
| Windjam Ltd | Manufacturing | 2018 |
| Windjen (Blaen Bowi) Limited | Energy | 2002 |
| Windjen Power Limited | Professional & scientific | 1995 |
| Windmill Heath Limited | Real estate | 1971 |
| Winwar Media Limited | Administrative & support | 2013 |
| Wissper Homes Ltd | Real estate | 2021 |
| Woodcroft Care Home Ltd | Health & social care | 2003 |
| Woodland Bay Ltd | Real estate | 2026 |
| Wordquarry Limited | Professional & scientific | 2025 |
| Work Panel Limited | Administrative & support | 2000 |
| Worthy Signs Limited | Manufacturing | 2025 |
| Wren of Serenity Limited | Other services | 2026 |
| Write on Time Science Ltd | Information & communication | 2016 |
| Wyatt Analytical Limited | Professional & scientific | 2021 |
| Wynne Davies Estate Agents (NW) Limited | Real estate | 2017 |
| Wynne Davies Estates Ltd | Real estate | 2013 |
| X Factory Ltd | Wholesale & retail | 2023 |
| X-Ray Mineral Services Ltd. | Professional & scientific | 2008 |
| XI SHI Limited | Hospitality | 2022 |
| XL Centre CIC | Education | 2021 |
| Y Bocs CIC | Arts & recreation | 2023 |
| Y Gaeddor Ltd | Extraterritorial | 2026 |
| Y M Engineering Ltd | Manufacturing | 2004 |
| YAS Consultants Limited | Health & social care | 2012 |
| Ymddiriedolaeth Gofalwyr Gogledd Cymru - Gwasanaethau Gofal Croesffyrdd Carers Trust North Wales - Crossroads Care Services | Health & social care | 2007 |
| Ymgynghoriaeth Rhos Consultancy CYF | Professional & scientific | 2026 |
| Yoke Creative Agency Ltd | Information & communication | 2019 |
| YR Orsedd Holdings Limited | Financial services | 2026 |
| ZEN Conwy Holding Ltd | Financial services | 2024 |
| ZEN Group of Companies London Ltd | Wholesale & retail | 2022 |