| Epiquest International Ltd | Health & social care | 2018 |
| Equiton Limited | Construction | 1997 |
| Equitrust Transport Ltd | Transport & logistics | 2025 |
| ER Commercial Properties Ltd | Real estate | 2021 |
| ERA Restaurant Ltd | Health & social care | 2024 |
| Eryri Apiaries Ltd | Agriculture & fishing | 2026 |
| Eryri Arboriculture & Consultancy Limited | Agriculture & fishing | 2024 |
| Eryri Construction CYF | Construction | 2019 |
| Eryri Properties Limited | Real estate | 1998 |
| Eryri Property Solutions Ltd | Real estate | 2024 |
| Eryri Renewables Ltd | Construction | 2022 |
| Eryri Solar Solutions Ltd | Construction | 2024 |
| Essential Inventories Limited | Professional & scientific | 2013 |
| Estate and Probate Services Limited | Other services | 2016 |
| Estates Development (N.I.) Limited | Real estate | 1955 |
| Estheteg Lowri Ogwen Aesthetics Ltd | Other services | 2023 |
| Eticketings Ltd | Hospitality | 2023 |
| Etifeddiaeth CYF. | Information & communication | 2024 |
| ETL Solutions Limited | Information & communication | 2001 |
| Etsy Ideas Ltd | Manufacturing | 2025 |
| Europeanswitch Ltd | Information & communication | 2026 |
| Evangelical Movement of Wales Trust Limited(The) | Other services | 1976 |
| Evans Motors NW Ltd | Wholesale & retail | 2025 |
| Evermore Fencing Ltd | Construction | 2015 |
| Eversley Park Lodge Limited | Hospitality | 2024 |
| Evesham Lane Management Company Limited | Extraterritorial | 2018 |
| Evolution Beics CYF. | Extraterritorial | 2023 |
| Evolv IT Ltd | Information & communication | 2023 |
| Evolve Bowling Ltd | Arts & recreation | 2024 |
| Evolve Occupational Therapy C.I.C. | Health & social care | 2023 |
| Evometric Ltd | Information & communication | 2022 |
| EW Partnership Limited | Professional & scientific | 2005 |
| EWP Construction Services Limited | Construction | 2020 |
| Exapt Group Limited | Information & communication | 2022 |
| Eximo Marketing Ltd | Professional & scientific | 2017 |
| Expansion Petrol SL Limited | Financial services | 2025 |
| Experienceni Ltd | Extraterritorial | 2025 |
| Extralap Limited | Construction | 2007 |
| Extraneat Limited | Construction | 2007 |
| Eyekiller Ltd | Information & communication | 2003 |
| Ezsalon Ltd | Information & communication | 2009 |
| Ezsolutions (N.I.) Ltd | Information & communication | 2009 |
| Faateh Ltd | Hospitality | 2022 |
| Faenol Events Ltd | Arts & recreation | 2010 |
| Fairground Solutions Ltd | Arts & recreation | 2026 |
| Fairleague Limited | Construction | 2007 |
| Falmer Student Brighton Limited | Real estate | 1993 |
| FAN Jones Properties Limited | Real estate | 2013 |
| FAR Dorcha Forensic Psychology Limited | Health & social care | 2023 |
| Farnham Lodge Management Company Limited | Extraterritorial | 1998 |
| Farrar Car Company Ltd | Real estate | 2026 |
| Farset Aero Engineering Limited | Professional & scientific | 2022 |
| Fashion 4 Kids Ltd | Wholesale & retail | 2019 |
| Fast Forward Fuel Limited | Information & communication | 2022 |
| Faster Fibre Ltd | Information & communication | 2023 |
| FCO Group Ltd | Real estate | 2022 |
| Fearndale Wealth Management Ltd | Financial services | 2024 |
| FEC Properties Limited | Real estate | 2023 |
| Federation of Family Practices North Down C.I.C. | Health & social care | 2015 |
| Felin Fawr CYF | Real estate | 2009 |
| Felin Fawr Slate & Marble Ltd | Manufacturing | 2026 |
| Felix Enterprises Bangor Ltd | Wholesale & retail | 2018 |
| Fermentrics (UK) Limited | Professional & scientific | 2025 |
| Fern & Thistle Stays Ltd | Real estate | 2026 |
| Ffenestri Cymru Windows Ltd | Extraterritorial | 1997 |
| Ffin Ltd | Arts & recreation | 2025 |
| Ffis Research Ltd | Professional & scientific | 2020 |
| FG Intro and Trekking Peaks Limited | Administrative & support | 2017 |
| FG Private Clients Limited | Administrative & support | 2017 |
| FG Snow and Ice Limited | Administrative & support | 2017 |
| FG Summits Limited | Administrative & support | 2017 |
| Fighted | Health & social care | 2017 |
| Find My App Ltd | Information & communication | 2021 |
| Finefashion Limited | Real estate | 2008 |
| Fingerprint Learning Limited | Other services | 2010 |
| Fired UP Films Limited | Information & communication | 2017 |
| First Ascent (U.K.) Limited | Wholesale & retail | 2000 |
| First Ascent Limited | Extraterritorial | 2010 |
| First Stage Dive Ltd | Wholesale & retail | 2026 |
| First Stop Windows Ltd | Manufacturing | 2015 |
| Fish on Line Ltd | Extraterritorial | 2014 |
| Fit for Purpose Training Ltd | Extraterritorial | 2024 |
| FIX My PC Bangor Ltd | Wholesale & retail | 2020 |
| FIX Phone MCR Ltd | Wholesale & retail | 2024 |
| FL Management Company Limited | Households | 2021 |
| Flamma Ltd | Construction | 2018 |
| Flannigan Developments Limited | Real estate | 2015 |
| Flat Rock Management Company Ltd | Extraterritorial | 2019 |
| Flat White Digital Ltd | Information & communication | 2019 |
| Flavourcraft Limited | Manufacturing | 2016 |
| Fletcherfi Ltd | Real estate | 2024 |
| Flobea Limited | Other services | 2025 |
| Flood Control (NI) Limited | Water & waste | 2008 |
| Flora Clinic Limited | Other services | 2024 |
| Flow Energy Solutions Ltd | Administrative & support | 2026 |
| Flow Physio NI Ltd | Health & social care | 2025 |
| Flow Real Ltd | Health & social care | 2021 |
| Flux Enviro Limited | Professional & scientific | 2020 |
| Fmlk Ltd | Health & social care | 2020 |
| FN Research Limited | Information & communication | 2013 |