| Fintac Care Limited | Health & social care | 2023 |
| Fire Made Event Ltd | Hospitality | 2018 |
| Fire Made Ltd | Hospitality | 2016 |
| Fire-Aid Academy Limited | Public administration | 2011 |
| Fire-Aid International Training Ltd | Public administration | 2004 |
| Fired UP Careers Ltd | Education | 2018 |
| Firestorm Services Limited | Professional & scientific | 2002 |
| Firethorn Place (Ewhurst) Management Company Limited | Households | 2022 |
| Fireun Limited | Professional & scientific | 2026 |
| Firewire Networks Ltd | Information & communication | 2025 |
| Firgo Barn Limited | Extraterritorial | 2008 |
| First 2 Recruit Ltd | Administrative & support | 2007 |
| First Byte Services Limited | Professional & scientific | 2000 |
| First Coding Limited | Education | 2017 |
| First Time Housing Limited | Construction | 2015 |
| Fish Holdings Limited | Financial services | 2015 |
| Fish Topco Limited | Financial services | 2015 |
| Fisherman's Reach Quidhampton Management Company Limited | Real estate | 2004 |
| Fisherton Consulting Limited | Professional & scientific | 2012 |
| Fisherton Ltd | Other services | 2020 |
| Fisherton Warehouse Ltd | Real estate | 2013 |
| Fishing 4 Flowers Limited | Education | 2026 |
| Fitness Design Limited | Arts & recreation | 2010 |
| Fitorfat Racing Limited | Administrative & support | 2018 |
| Fitz-Henry Hill Limited | Real estate | 2020 |
| Fitzbride Ltd | Hospitality | 2005 |
| Fitzgerald Property Limited | Real estate | 2024 |
| Fitzwilliam Development Company Limited | Construction | 2022 |
| Fitzwilliam Trust Corporation Limited | Professional & scientific | 1982 |
| Five Rivers Child Care Limited | Health & social care | 2001 |
| Five Rivers Indoor Bowls Club (Salisbury) Limited | Arts & recreation | 2011 |
| Five Rivers Recruitment Limited | Administrative & support | 2004 |
| Fiwi Style Ltd | Hospitality | 2026 |
| Fjordr Limited | Professional & scientific | 2011 |
| FK Carpentry Limited | Construction | 2018 |
| Flammable Ice Limited | Extraterritorial | 2011 |
| Flammable Records UK Limited | Extraterritorial | 2011 |
| Flamsteed Court Management Limited | Real estate | 2012 |
| Flamstone Limited | Professional & scientific | 2012 |
| Flamstone Logs Limited | Hospitality | 2002 |
| Flat 12, 121 Marine Parade Limited | Real estate | 2015 |
| Flatstreamed Ltd | Professional & scientific | 2023 |
| Flawless Spaces South West Limited | Administrative & support | 2021 |
| Flea App Ltd | Information & communication | 2025 |
| Fleetwood & Hicks Limited | Real estate | 2022 |
| Fleming Court Financial Services LLP | | 2004 |
| Flemings Plumbing and Heating Ltd | Construction | 2024 |
| Flexiloo LLP | | 2008 |
| Flight Around the World Ltd | Arts & recreation | 2024 |
| Flight Dynamics International Ltd | Professional & scientific | 2016 |
| Flight Media Ltd | Information & communication | 2025 |
| Flight Training Systems Limited | Professional & scientific | 2002 |
| Flightspeed Downton Limited | Professional & scientific | 2019 |
| Flooring for Business Limited | Wholesale & retail | 2013 |
| Flora Garden Animals Ltd | Agriculture & fishing | 2024 |
| Florence Court & Mews Management Company Limited | Households | 2021 |
| Florence Court Apartments Management Company Limited | Households | 2021 |
| Flow Communications UK Limited | Information & communication | 2008 |
| Flow Roofing Solutions Ltd | Construction | 2025 |
| Flowplant (Scotland) Limited | Professional & scientific | 1999 |
| Flowplant Group Limited | Manufacturing | 1998 |
| Flowplant Holdings Limited | Professional & scientific | 2007 |
| Flowstead Drainage Ltd | Water & waste | 2026 |
| Flowvision Ltd | Information & communication | 2017 |
| Floyd Borderville Trustee 2 Ltd | Other services | 2024 |
| Floyd Borderville Trustee Ltd | Other services | 2024 |
| Fluent Foxes Ltd | Education | 2024 |
| Fluffetts Farm Ltd | Agriculture & fishing | 2001 |
| Fluid Profiling Limited | Manufacturing | 2012 |
| Fluiduk Ltd | Construction | 2007 |
| FLY Wright Aviation Services Ltd | Transport & logistics | 2015 |
| Flyer AI Ltd | Professional & scientific | 2025 |
| Flynn Duggan Holdings Limited | Financial services | 2026 |
| Flynn Lees Consulting Limited | Health & social care | 2020 |
| FMB Legacy Ltd | Real estate | 2026 |
| FMD Enterprises Limited | Professional & scientific | 2018 |
| FMG EOT Trustee Limited | Other services | 2025 |
| FMJ Logistics Limited | Transport & logistics | 2024 |
| FMS Security Ltd | Administrative & support | 2025 |
| Focal Point VR Ltd | Information & communication | 2015 |
| Focal.Jmlab UK Limited | Administrative & support | 2001 |
| Focus Mags Ltd | Information & communication | 2022 |
| Focus Work Ltd | Professional & scientific | 2026 |
| Folbright Properties Limited | Financial services | 1996 |
| Folded Laundry Limited | Other services | 2026 |
| Foliot House Residents Ltd | Households | 2020 |
| Folkestone High Holborn (Number 1) Limited | Real estate | 2002 |
| Folkestone High Holborn (Number 2) Limited | Real estate | 2002 |
| Folland Aircraft Limited | Transport & logistics | 2023 |
| Folley a Limited | Construction | 1992 |
| Folly Hill (Farnham) Management Company Limited | Households | 2019 |
| Fone N Vape Ltd | Wholesale & retail | 2025 |
| Fonthill Estate Nominees (NO1) Limited | Extraterritorial | 2023 |
| Fonthill Estate Nominees (NO2) Limited | Extraterritorial | 2023 |
| Fonthill Farming Company | Agriculture & fishing | 1971 |
| Food & FIX Ltd | Hospitality | 2026 |
| Food for Happiness Limited | Information & communication | 2015 |
| FOR the Love of Water (Flow) CIC | Professional & scientific | 2022 |
| Foray 2025 Limited | Other services | 2025 |
| Foray Holdings Limited | Professional & scientific | 2000 |