| Fairman Holdings Ltd | Construction | 2013 |
| Fairmont Management Company Limited | Real estate | 2025 |
| Fairmount Farm Ltd | Agriculture & fishing | 2016 |
| Fallow Ward Ltd | Hospitality | 2024 |
| FAR and Wild CIC | Arts & recreation | 2011 |
| FAR East Derry Ltd | Hospitality | 2021 |
| Farah Partitions Ltd | Construction | 2026 |
| Farm Carbon Zero NI CIC | Professional & scientific | 2023 |
| Farway Contracts Limited | Construction | 2024 |
| Fashion Junkie UK Ltd | Wholesale & retail | 2016 |
| Fastek Services Limited | Administrative & support | 2021 |
| Faughanside Construction Ltd | Construction | 2024 |
| Faughanside Developments Ltd | Construction | 2015 |
| FCC Property Group Limited | Construction | 2024 |
| FD Exchange Limited | Wholesale & retail | 2008 |
| FD Payroll Limited | Administrative & support | 2024 |
| FD Retailing Ltd | Wholesale & retail | 2018 |
| Federation of Family Practices Derry C.I.C. | Health & social care | 2014 |
| Feeny Community Association Limited | Other services | 1998 |
| Feeny Foods Ltd | Professional & scientific | 2018 |
| Feeny Pharmacy Limited | Wholesale & retail | 2012 |
| Fegra Ltd | Wholesale & retail | 2020 |
| FEL Developments Limited | Construction | 2024 |
| Ferm Construction Ltd | Construction | 2007 |
| Ferry Financial Services Ltd | Professional & scientific | 2025 |
| Ferryquay Suites Ltd | Real estate | 2026 |
| FFP Group Ltd | Construction | 2023 |
| FG Utility Services Ltd | Construction | 2021 |
| Field Productions Ltd | Professional & scientific | 2021 |
| Fight Force Five C.I.C. | Arts & recreation | 2024 |
| FIN Moto Limited | Wholesale & retail | 2023 |
| Final Trim Solutions (NI) Ltd | Construction | 2021 |
| Finest Hand Car Wash Ltd | Other services | 2018 |
| Finnesse Careers and Empowerment C.I.C. | Education | 2023 |
| Fintech Advisory Services Limited | Professional & scientific | 2023 |
| Fionn Enterprises Ltd | Professional & scientific | 2025 |
| Fire Safety and Management Services Ltd | Professional & scientific | 2022 |
| Firex Ltd | Public administration | 2024 |
| First Derry Limited | Other services | 2024 |
| First Housing AID & Support Services | Health & social care | 1997 |
| Fitin Elite Sports Management Ltd | Professional & scientific | 2024 |
| Fitzroy's Restaurants Limited | Hospitality | 2001 |
| Fitzroy’S Bistro Ltd | Hospitality | 2023 |
| Fixit Platform Ltd | Professional & scientific | 2025 |
| Flac Farms Limited | Agriculture & fishing | 2025 |
| Fleming Holdco Limited | Professional & scientific | 2018 |
| Flite Software (N.I.) Limited | Information & communication | 1996 |
| FLORIDA24 Limited | Transport & logistics | 2024 |
| Flowstate Media Ltd | Professional & scientific | 2025 |
| Flowtera AI Limited | Information & communication | 2026 |
| FMB Commercial Ltd | Households | 2022 |
| FMB Property Management Limited | Real estate | 2020 |
| FMN Services Limited | Construction | 2015 |
| FNW Group Ltd | Professional & scientific | 2012 |
| Focus Gym Coaching Ltd | Arts & recreation | 2020 |
| Foma Limited | Real estate | 2014 |
| Fone Trading Zone Limited | Wholesale & retail | 2006 |
| Fooc Films Limited | Information & communication | 2016 |
| Food Ordering Ltd | Information & communication | 2023 |
| Foods Connected Ltd | Information & communication | 2012 |
| Football FUN Factory (Community 109) Limited | Arts & recreation | 2023 |
| Forbulous Group Ltd | Wholesale & retail | 2021 |
| Foreglen Developments Limited | Construction | 2015 |
| Foreglen Shop Ltd | Wholesale & retail | 2024 |
| Forge Equestrian Ltd | Education | 2022 |
| Forge Heights Ltd | Wholesale & retail | 2024 |
| Fort Mckay Ltd | Real estate | 2017 |
| Forthouse Management Company Ltd | Real estate | 2012 |
| Fortuna Enterprises Limited | Hospitality | 2002 |
| Forward Financial Management Limited | Professional & scientific | 2020 |
| Fountain Hill Ltd | Hospitality | 2015 |
| Foxhat FX Limited | Information & communication | 2016 |
| Foyle Aesthetics Limited | Health & social care | 2015 |
| Foyle and Fenway Group Ltd | Real estate | 2025 |
| Foyle and Marine Dredging Limited | Construction | 2012 |
| Foyle Bakery Ltd | Manufacturing | 2026 |
| Foyle Business Park Limited | Real estate | 2023 |
| Foyle Child Contact Centre | Health & social care | 2012 |
| Foyle DAB Ltd | Information & communication | 2020 |
| Foyle Dambovita 3 Limited | Financial services | 2007 |
| Foyle Dambovita Ltd | Financial services | 2006 |
| Foyle District Motor Cycle Club Limited | Arts & recreation | 1999 |
| Foyle Family Justice Centre C.I.C. | Public administration | 2021 |
| Foyle Fencing & Paving Ltd | Construction | 2024 |
| Foyle Film Projects Limited | Arts & recreation | 1987 |
| Foyle Foot & Ankle Clinic Ltd | Health & social care | 2023 |
| Foyle Home Care Limited | Health & social care | 2024 |
| Foyle International Removals, Storage Ltd | Transport & logistics | 2018 |
| Foyle Investments Limited | Real estate | 2017 |
| Foyle Lettings Limited | Households | 2015 |
| Foyle Management Solutions Limited | Real estate | 2014 |
| Foyle Nails & Spa Ltd | Other services | 2024 |
| Foyle Network Foundation Ltd | Hospitality | 2016 |
| Foyle Plastering Construction Ltd | Construction | 2013 |
| Foyle Projects Ltd | Real estate | 2017 |
| Foyle Properties Limited | Real estate | 2013 |
| Foyle Properties Sales & Management Limited | Real estate | 2015 |
| Foyle Road Enterprises Limited | Real estate | 2019 |
| Foyle Safety Services Ltd | Public administration | 2013 |
| Foyle Search and Rescue | Other services | 2016 |