| Fight for Fitness Ltd | Poole | 2011 |
| Fight Force Five C.I.C. | Londonderry | 2024 |
| Fight Game Management Ltd | Liverpool | 2024 |
| Fight Hub Basingstoke Ltd | Basingstoke | 2023 |
| Fight Inc International Ltd | Bolton | 2025 |
| Fight Inc. Ltd. | Bolton | 2017 |
| Fight Industries Limited | Liverpool | 2010 |
| Fight Klub Franchising Limited | Norwich | 2024 |
| Fight Klub Limited | Norwich | 2016 |
| Fight Life Boxing Limited | Chesterfield | 2022 |
| Fight Nation Limited | Camberley | 2025 |
| Fight Night Entertainment Limited | Southport | 2020 |
| Fight Night Promotions Ltd. | London | 2008 |
| Fight Night STA Ltd | London | 2022 |
| Fight Project BJJ C.I.C. | Llanelli | 2025 |
| Fight Project Gym Limited | Carmarthen | 2023 |
| Fight Science Limited | Aldershot | 2009 |
| Fight Sense Limited | London | 2025 |
| Fight Starter Ltd | Solihull | 2004 |
| Fight the Demons Ltd | Herne Bay | 2025 |
| Fight Zone Media Ltd | Sheffield | 2019 |
| Fight&Fitness Limited | Darlington | 2022 |
| FIGHT2THRIVE CIC | Larne | 2023 |
| Fighter Collection Limited (the) | Cambridge | 1985 |
| Fighter Training Online Academy Ltd | Nottingham | 2020 |
| Fighters Republic CIC | Slough | 2020 |
| Fightface Ltd | Kent | 2022 |
| Fightfest Ltd | Stockton-On-Tees | 2024 |
| Fightfit Fitness Limited | Oldmeldrum | 2013 |
| Fightfit MMA Keighley Ltd | Keighley | 2026 |
| Fightinfit Limited | High Peak | 2005 |
| Fighting 2 Fitness Ltd | Harrow | 2024 |
| Fighting Falcons Ltd | Andover | 2017 |
| Fighting Fit Collective Ltd | Ruislip, | 2025 |
| Fighting Fit Events Limited | Bromsgrove | 2017 |
| Fighting Fit Limited | Suffolk | 2000 |
| Fighting Fit Martial Arts & Fitness Limited | London | 1999 |
| Fighting Fit Partnership Ltd | Lichfield | 2023 |
| Fighting Fit Performance Ltd | St. Ives | 2025 |
| Fighting Fit Sports Ltd | Upshire | 2010 |
| Fighting Fit Torfaen | Pontypool | 2012 |
| Fighting Fit Training Limited | Glasgow | 2010 |
| Fighting Fit Training Systems Limited | Edinburgh | 2010 |
| Fighting for Futures CIC | Bristol | 2025 |
| Fighting Spirit Wellbeing C.I.C. | Manchester | 2019 |
| Fighting Stigma Coaching Ltd | Bolton | 2025 |
| Fightingfitgla Ltd | Glasgow | 2025 |
| Fightingforfitness Limited | Liverpool | 2022 |
| Fightlight Ltd | Hockley | 2024 |
| Fights and Fancy Ltd | Scarborough | 2023 |
| Fightsportsuk Limited | Harlow | 2016 |
| Fightstar Championship Global Limited | London | 2026 |
| Fighttally Ltd | London | 2025 |
| Fightworx Academy Newton Abbot Ltd | Newton Abbot | 2022 |
| Figment Arts Community Interest Company | Worthing | 2007 |
| Figment Creative Works Ltd | London | 2025 |
| Figment Films Limited | | 1993 |
| Figment INK Limited | Kingston | 2013 |
| Figment Limited | Cranbrook | 2003 |
| Figs in Wigs (2022) Ltd | Cambridge | 2022 |
| Figura Collective ORG C.I.C. | London | 2025 |
| Figuration Limited | London | 2016 |
| Figure 8 Ltd | High Wycombe | 2025 |
| Figure 8 Publishing Ltd | London | 2015 |
| Figure 8 Studios Limited | London | 2022 |
| Figure Ensemble Limited | London | 2022 |
| Figure Factory (Halton) Limited | London | 2013 |
| Figure Pilates Limited | Preston | 2025 |
| Figurebygurleen Ltd | Sheffield | 2021 |
| Figuregot Ltd | Solihull | 2022 |
| Figurehead Studios Ltd | Harrogate | 2022 |
| Fiit Box Ltd | Sittingbourne | 2018 |
| Fiit Coaching Limited | London | 2013 |
| Fiit Factory Limited | Killingworth | 2020 |
| Fiit Training Ltd | Harrogate | 2018 |
| Fiitlab Ltd | Dunstable | 2023 |
| Fiitzone Online Limited | Bromley | 2025 |
| Fiiys Ltd | Denham | 2025 |
| Fika Wellness Studio Limited | Lymm | 2023 |
| Fikamovement Ltd | Newcastle Upon Tyne | 2025 |
| FIL Fitness Studio Limited | Woking | 2014 |
| FIL Rouge Press Ltd | London | 2007 |
| FIL-101 Ltd | Aldershot | 2010 |
| Filament Creative Studio Limited | Whitley Bay | 2025 |
| Filament Theatre Company Limited | Reading | 2012 |
| Filanthropy* CIC | London | 2013 |
| Filbert Realisations NO 1 PLC | Cardiff | 1919 |
| Filbrit Connect Ltd | Dartford | 2025 |
| Filey Brigg Angling Society Limited | Driffield | 2011 |
| Filey Brigg Ornithological Group and Bird Observatory Limited | Bridlington | 2007 |
| Filey Community Sports Club Ltd | Filey | 2002 |
| Filey Golf and Recreation Company Limited(The) | Filey | 1897 |
| Filey ZOO Ltd | Filey | 2013 |
| Filipino Community of Oxfordshire Community Interest Company | Oxford | 2021 |
| Filiz Art Ltd | Birmingham | 2025 |
| Fill Support Ltd | Surbiton | 2025 |
| Fill Your Boots Ltd | Worcester Park | 2018 |
| Filling in the MAP Limited | London | 2026 |
| Filling Meals Limited | Petersfield | 2025 |
| Filling Station Facilities Ltd | Wirral | 2009 |