| Farcet FEN Limited | Agriculture & fishing | 2016 |
| Farhan Ltd | Wholesale & retail | 2024 |
| Farjana Enterprise Limited | Hospitality | 2023 |
| Farkas Composites Ltd | Manufacturing | 2022 |
| Farm Data Principles Limited | Other services | 2023 |
| Farm Forge Ltd | Wholesale & retail | 2025 |
| Farm Supply Company (Thirsk) Limited | Agriculture & fishing | 1967 |
| Farmhouse Productions Ltd | Information & communication | 2025 |
| Farmriver Property Management Limited | Households | 1983 |
| Farnell Construction Limited | Construction | 2019 |
| Farontone Limited | Real estate | 1978 |
| Faroz Kitchen Ltd | Hospitality | 2022 |
| Faroz Ltd | Hospitality | 2025 |
| Farraday Equine Limited | Agriculture & fishing | 2016 |
| Farrell Construction (Cambridge) Ltd | Construction | 2012 |
| Farrer Joinery Ltd | Manufacturing | 2024 |
| Farsight Partners Ltd | Professional & scientific | 2021 |
| Farsight Sentinel Ltd | Professional & scientific | 2026 |
| Farsilk Limited | Health & social care | 2016 |
| Farthings DRY Cleaners Ltd. | Other services | 2022 |
| Farvic Industry Co., Ltd | Extraterritorial | 2014 |
| Fascia Expressions Ltd | Construction | 2009 |
| Fashionbourne Limited | Administrative & support | 1981 |
| Fast Executive Ltd | Transport & logistics | 2019 |
| Fast Online Distribution Ltd | Wholesale & retail | 2024 |
| Fasta Industry Company Ltd | Extraterritorial | 2023 |
| Fastbreak Basketball Limited | Education | 2019 |
| Fastbuildconstructions Ltd | Construction | 2025 |
| Fastep International Co., Ltd | Wholesale & retail | 2023 |
| Fastfix Plumbing Ltd | Construction | 2025 |
| Fastian Investments Limited | Wholesale & retail | 2020 |
| Fastresponse Plumbing Ltd | Construction | 2025 |
| Fasttrack Talent Solutions Ltd | Administrative & support | 2024 |
| Fasulo Developments Ltd | Construction | 2024 |
| FAT Poppadaddys Ltd | Arts & recreation | 2003 |
| Fatahan Group Ltd | Hospitality | 2024 |
| Fatoi Aviation Maintenance Ltd | Manufacturing | 2025 |
| Fattouh Import and Export Co., Ltd | Wholesale & retail | 2025 |
| Fauna & Flora International | Other services | 1992 |
| Favilla Osteria Limited | Hospitality | 2026 |
| Fawndale Rise Residents Management Company Limited | Households | 2026 |
| Fawzy Group for General Trading Co., Ltd | Wholesale & retail | 2023 |
| Fayrestabil Limited | Hospitality | 1972 |
| Fbre Consulting Ltd. | Agriculture & fishing | 2017 |
| Fbreader Books Limited | Wholesale & retail | 2024 |
| Fbreader.Org Limited | Information & communication | 2013 |
| Fc-Films Ltd | Information & communication | 2022 |
| Fcdf Medical Limited | Professional & scientific | 2019 |
| Fcfgfs Ltd | Information & communication | 2024 |
| Fcftr Limited | Information & communication | 2019 |
| FCI Property Investment Limited | Real estate | 2023 |
| Fcit Solutions Ltd | Information & communication | 2017 |
| Fcri Solutions Ltd | Professional & scientific | 2025 |
| FCT Compliance Ltd. | Professional & scientific | 2017 |
| FDM Pet Retreat and Academy Ltd | Other services | 2025 |
| Fearless Sportswear Limited | Wholesale & retail | 2025 |
| Feather Systems Ltd | Professional & scientific | 2023 |
| FEB Projects Ltd | Professional & scientific | 2024 |
| FEC BIO Limited | Professional & scientific | 2014 |
| Feersum Technology Limited | Information & communication | 1997 |
| Feimier International Jewelry Co., Ltd | Wholesale & retail | 2025 |
| Feiting Pipe Engineering Co., Ltd | Construction | 2023 |
| Feiyu Limited | Wholesale & retail | 2021 |
| Felbrigge (Hills Road) Management Company Limited | Real estate | 2003 |
| Felix Digital Ltd | Information & communication | 2026 |
| Felix Express Ltd | Wholesale & retail | 2014 |
| Felix M & M Ltd | Professional & scientific | 2019 |
| Fellingham Contracting Ltd | Information & communication | 1997 |
| Fellowes Road Property Management Limited | Households | 2005 |
| Fellows Brewery Limited | Manufacturing | 2009 |
| Fellowship Square Residents Management Company Limited | Households | 2024 |
| Felocity Ltd | Information & communication | 2025 |
| Felstead Court Management Company Limited | Households | 1993 |
| Femeaviation Ltd | Manufacturing | 2026 |
| FEN Consultants Ltd | Information & communication | 2013 |
| FEN Edge Services Limited | Manufacturing | 2018 |
| FEN END Management Company Limited | Households | 2008 |
| FEN EP Limited | Manufacturing | 2014 |
| FEN Farming Limited | Wholesale & retail | 2020 |
| FEN Feeds Limited | Wholesale & retail | 2002 |
| FEN Homecare Ltd | Health & social care | 2018 |
| FEN House Property Limited | Real estate | 2014 |
| FEN Medtech Ltd | Professional & scientific | 2025 |
| FEN Radio Limited | Information & communication | 2025 |
| FEN Research Limited | Information & communication | 2010 |
| FEN Systems Ltd. | Information & communication | 2000 |
| FEN Technology Limited | Information & communication | 2012 |
| FEN View Court Limited | Real estate | 2018 |
| Fengcheng Huazeng Industrial Co., Ltd | Manufacturing | 2020 |
| Fengchu Food (UK) Co., Ltd. | Wholesale & retail | 2025 |
| Fengzhan Trading Co., Ltd | Extraterritorial | 2020 |
| Fenix Helicopters Ltd | Manufacturing | 2025 |
| Fenland Chamber of Commerce Limited | Professional & scientific | 2005 |
| Fenland Flat Roofing Limited | Construction | 1976 |
| Fenland Holdings Ltd | Financial services | 2008 |
| Fenland Holdings Trustees Limited | Other services | 2024 |
| Fenland Property Holdings Ltd | Real estate | 2026 |
| Fenland Safety Services Limited | Professional & scientific | 2013 |
| Fenlax UK Limited | Agriculture & fishing | 2013 |
| Fenprop Ltd | Financial services | 2025 |