| Founder's Office Ltd | Professional & scientific | 2026 |
| Fountain Blue Limited | Information & communication | 2015 |
| Fountains (Ballards Lane) Limited (the) | Real estate | 1973 |
| Four Acres Holdings Ltd | Financial services | 2021 |
| Four Acres Lettings Ltd | Real estate | 2021 |
| Four Cranes Consulting Limited | Professional & scientific | 2020 |
| Four Line Matter Limited | Professional & scientific | 2025 |
| Four Perfect Seasons Limited | Wholesale & retail | 2023 |
| Four Space Joinery Ltd | Arts & recreation | 2023 |
| Four Square Spaces Limited | Wholesale & retail | 2025 |
| Fourdees Capital Limited | Real estate | 2025 |
| Fourdees Consultancy Limited | Professional & scientific | 2016 |
| Fourfold Media Limited | Information & communication | 2009 |
| Fourkbs Infra Limited | Real estate | 2023 |
| Fourseven Consulting Ltd | Information & communication | 2018 |
| Fourth Story Limited | Professional & scientific | 2014 |
| FOX and Form Ltd | Wholesale & retail | 2025 |
| FOX London Properties Ltd | Real estate | 2021 |
| FOX Scenic Carpentry Limited | Construction | 2012 |
| Foxbolt Courier Ltd | Transport & logistics | 2025 |
| Foxcloud LLP | | 2013 |
| Foxleys Property Services Limited | Real estate | 2003 |
| Foxtrot Security Limited | Administrative & support | 2023 |
| FPD Investments Limited | Real estate | 2023 |
| Fraan Ltd | Construction | 2019 |
| Fractionall Services Limited | Professional & scientific | 2016 |
| Fractionwerk Limited | Professional & scientific | 2025 |
| Fragranceexpert Limited | Wholesale & retail | 2006 |
| Frame Construction Ltd | Construction | 2018 |
| Frame Modus Engineering Ltd | Professional & scientific | 2026 |
| Frames by Disha Limited | Professional & scientific | 2024 |
| Frances Grace Property Services Limited | Real estate | 2023 |
| Francesca James Limited | Information & communication | 2008 |
| Francis Bioventures Limited | Professional & scientific | 2021 |
| Franco Express Ltd | Hospitality | 2018 |
| Francois Consulting Ltd | Professional & scientific | 2025 |
| Franks Consulting & Advisory Ltd | Administrative & support | 2024 |
| Fransesca Care Limited | Health & social care | 2025 |
| Fraser Design Associates Limited | Professional & scientific | 1991 |
| Fratelli Watford Ltd | Hospitality | 2024 |
| Fratres Recruitment Ltd | Administrative & support | 2006 |
| Frauducation Ltd | Professional & scientific | 2018 |
| Fravashi Holdings Limited | Real estate | 2018 |
| Frays Stream Ltd | Real estate | 2016 |
| FRD Construction Ltd | Construction | 2020 |
| Freaky Shakes Limited | Wholesale & retail | 2018 |
| Freddy & O. Sons Property Limited | Real estate | 2024 |
| Free Eco Funding Limited | Administrative & support | 2020 |
| Freedom 2 Drive Limited | Education | 2007 |
| Freedomt Ltd | Education | 2021 |
| Freehold Estates Limited | Real estate | 1996 |
| Freehold Properties 20 Limited | Real estate | 2005 |
| Freehold Properties 21 Limited | Real estate | 2005 |
| Freehold Properties 250 Limited | Real estate | 2008 |
| Freehold Properties 251 Limited | Real estate | 2005 |
| Freehold Properties 252 Limited | Real estate | 2019 |
| Freehold Properties 253 Limited | Real estate | 2019 |
| Freehold Properties 254 Limited | Real estate | 2019 |
| Freehold Properties 38 Limited | Real estate | 2007 |
| Freehold Properties 43 Limited | Real estate | 2007 |
| Freehold Properties 50 Limited | Real estate | 2022 |
| Freehold Securities Limited | Real estate | 1994 |
| Freelance Managment Ltd | Agriculture & fishing | 2014 |
| Freestyle Beauty Products Limited | Financial services | 1999 |
| Freewood House Consulting Limited | Construction | 2018 |
| Freightco (UK) Ltd | Administrative & support | 2021 |
| French Cycling Holidays Limited | Administrative & support | 2002 |
| French Pharma Ltd | Wholesale & retail | 2025 |
| French Residential LLP | | 2023 |
| Frenchie Autos Ltd | Manufacturing | 2010 |
| Frenzy Films Ltd | Information & communication | 2012 |
| Fresco Holding LP | | 2017 |
| Fresh Computing Ltd | Information & communication | 2010 |
| Fresh Grocers Limited | Wholesale & retail | 2019 |
| Fresh View Coaching and Educational Consultancy Ltd | Professional & scientific | 2025 |
| Fretz Productions Ltd | Administrative & support | 2019 |
| Frico Holding Limited | Construction | 1989 |
| Friendship Scouts Group Ltd | Mining & quarrying | 2018 |
| Frith Wilock Consultant Advisory Services Ltd | Professional & scientific | 2018 |
| Frizbee.Net Limited | Information & communication | 2003 |
| Frogmore House Ltd | Real estate | 2024 |
| From Survive to Thrive Ltd | Health & social care | 2025 |
| Fronks Estates Ltd | Real estate | 2023 |
| Front Foot Devcap Limited | Professional & scientific | 2021 |
| Frontier Removals & Logistics Ltd | Transport & logistics | 2025 |
| Frontline Solutions Limited | Information & communication | 2017 |
| Frontline Transfers Ltd | Transport & logistics | 2024 |
| Frontline Uniformed Services Equipment and Clothing Ltd | Wholesale & retail | 2024 |
| Frontrunner Recruitment Limited | Administrative & support | 2011 |
| Fruit Tier Ltd | Professional & scientific | 2015 |
| FRY & Harper's Consultancy Limited | Education | 2019 |
| FSG Property Consultants Ltd | Real estate | 2025 |
| Fssgreen Biotechnology Limited | Professional & scientific | 2023 |
| Fssgreen International (Holding) Limited | Professional & scientific | 2021 |
| Fsstechnologies (UK) Limited | Information & communication | 2009 |
| FT Refurbishing Ltd | Water & waste | 2017 |
| Ftikas Consulting Ltd | Professional & scientific | 2019 |
| Ftsl Consulting Ltd | Information & communication | 2015 |
| Fudco Limited | Wholesale & retail | 2021 |
| Fuji Homes Limited | Construction | 2024 |