| Fittments Ltd | Wholesale & retail | 2025 |
| Fitz Advisory Ltd | Professional & scientific | 2021 |
| Fitzpatrick Total Home Care Limited | Health & social care | 2010 |
| Five Stars Performance Limited | Information & communication | 2023 |
| Fiveways Farming Limited | Agriculture & fishing | 2018 |
| Fizzbomb Ltd | Other services | 1993 |
| FJB Timepieces Ltd | Wholesale & retail | 2024 |
| FJE & Co Ltd | Health & social care | 2014 |
| Fjord and Stone Ltd | Construction | 2026 |
| FJS Resells Ltd | Wholesale & retail | 2026 |
| FJX Solutions Limited | Other services | 2018 |
| Flagstaff Consultants Ltd | Administrative & support | 2018 |
| Flash Body Inspirations Ltd | Extraterritorial | 2011 |
| Flatford Lodges Management Company Limited | Hospitality | 2020 |
| Flatgroup Limited | Professional & scientific | 1995 |
| Flatt Walls Ltd | Construction | 2020 |
| Flawless by Gabbie Ltd | Other services | 2023 |
| Flawless Glazing Ltd | Construction | 2011 |
| Flawless Soil Testing Ltd | Professional & scientific | 2022 |
| Fleet Automotive Holdings Limited | Professional & scientific | 2020 |
| Fleetshield Services Limited | Wholesale & retail | 2005 |
| Fletcher Bay Group Limited | Professional & scientific | 2009 |
| Fletcher Bay Properties Limited | Professional & scientific | 2020 |
| Fletcher Bay Warwick Limited | Professional & scientific | 2021 |
| Fletchers Farm Riding Limited | Arts & recreation | 2023 |
| Fleur Marie Design Limited | Professional & scientific | 2020 |
| Fleur Nails & Beauty Ltd | Other services | 2019 |
| Flex Design Limited | Information & communication | 2010 |
| Flex Hand Car Wash Ltd | Administrative & support | 2026 |
| Flexfityoga CIC | Health & social care | 2023 |
| Flexible Storage Holdings Limited | Administrative & support | 2021 |
| Flexible Storage Solutions Ltd | Transport & logistics | 2005 |
| Flexichefuk Limited | Hospitality | 2025 |
| Flight Training Essex Ltd | Education | 2023 |
| Flightworx Air Solutions Limited | Transport & logistics | 2025 |
| Flightworx Aviation Limited | Transport & logistics | 2008 |
| Flightworx Fuel Services Limited | Administrative & support | 2009 |
| Flintmo Homes Limited | Health & social care | 2024 |
| Flips Academy Ltd | Education | 2026 |
| Flipvision Ltd | Information & communication | 2023 |
| Float Network Ltd | Arts & recreation | 2021 |
| Floflame Ltd | Construction | 2025 |
| Floor Sanding and Restoration Limited | Construction | 2007 |
| Floozy Boutique Ltd | Wholesale & retail | 2019 |
| Floradale Limited | Real estate | 1998 |
| Floramedia (U.K.) Limited | Manufacturing | 1981 |
| Florettee Limited | Wholesale & retail | 2023 |
| Flosafe Plumbing & Heating Ltd | Construction | 2019 |
| Flosafe Property Limited | Real estate | 2023 |
| Flow Performance & Wellness Limited | Arts & recreation | 2012 |
| Flow Performance & Wellness Rowhedge Limited | Arts & recreation | 2026 |
| Flowingstars Limited | Transport & logistics | 2023 |
| Flowline Builders Limited | Construction | 1997 |
| Flowpulse Ltd | Wholesale & retail | 2019 |
| FLS Railway Solutions Ltd | Education | 2019 |
| Fluck AI Ltd | Information & communication | 2024 |
| Fluency Agency Limited | Professional & scientific | 2024 |
| Fluid Pools Ltd | Construction | 2025 |
| Fluid Projects Limited | Construction | 2005 |
| Fluid Skiing Ltd | Arts & recreation | 2023 |
| Fluidlines Ltd | Wholesale & retail | 2009 |
| Fluval UK Limited | Real estate | 1994 |
| Fluxdesk Ltd | Information & communication | 2025 |
| Fluxus Engineering Limited | Extraterritorial | 2003 |
| Fluxus Technology Ltd | Information & communication | 1999 |
| FLY View Global Ltd | Construction | 2026 |
| Flybeestravel Ltd | Administrative & support | 2025 |
| Flyhighclub Ltd | Professional & scientific | 2023 |
| Flying 7 Limited | Real estate | 2014 |
| Flying 8’S Ltd | Arts & recreation | 2024 |
| Flynn Development Group Ltd | Construction | 2026 |
| Flynn Roofing Services Limited | Construction | 2021 |
| FM (Derby) Limited | Professional & scientific | 2009 |
| FM Hatton Group Limited | Extraterritorial | 2016 |
| Fm&B Limited | Professional & scientific | 2024 |
| FMA Consulting Limited | Administrative & support | 2005 |
| FOB Property Ltd | Real estate | 2023 |
| Focus Ecommerce Limited | Professional & scientific | 2018 |
| Focus Ridge Limited | Professional & scientific | 2017 |
| Focused Chef Limited | Administrative & support | 2019 |
| Fogerty-Smith Properties Ltd | Real estate | 2020 |
| Fogher UK Limited | Extraterritorial | 2024 |
| Foley & Sons Paving Ltd | Construction | 2021 |
| Folkadot Ltd | Wholesale & retail | 2020 |
| Fontaine & Fontaine Ltd | Information & communication | 2023 |
| Food and Drink Festivals UK Ltd | Hospitality | 2010 |
| Food for Thought Heathfield CIC | Hospitality | 2020 |
| Food Inc Colchester Limited | Wholesale & retail | 2010 |
| Food Simply Ltd | Wholesale & retail | 2026 |
| Food Sooo Good Ltd | Hospitality | 2024 |
| Foodify Ltd | Wholesale & retail | 2012 |
| Foodnaija Ltd | Wholesale & retail | 2026 |
| Foodpage Ltd | Information & communication | 2023 |
| Football Careers Centre Limited | Arts & recreation | 2003 |
| Football FUN Day Limited | Arts & recreation | 2021 |
| Footings Direct Developments Limited | Real estate | 2011 |
| Footings Direct Limited | Construction | 2003 |
| Footprint Digital Limited | Professional & scientific | 2011 |
| Footprints Beauty Limited | Other services | 2008 |
| Foots Farm Management Company Limited | Real estate | 2018 |