| Finishline Business Solutions Ltd | Financial services | 2026 |
| Finite Field Training Limited | Education | 2023 |
| Finsbury Capital Limited | Extraterritorial | 2007 |
| Finsbury Holdings Limited | Extraterritorial | 2007 |
| Finsbury Investments Limited | Extraterritorial | 2007 |
| Finsbury Managers Limited | Extraterritorial | 2018 |
| Finsbury Productions (Trading and Finance) Co. Limited | Financial services | 1959 |
| Fireball Consulting Limited | Information & communication | 2010 |
| Firesense Limited | Wholesale & retail | 1992 |
| Firm Ideas Limited | Professional & scientific | 2003 |
| First and Last Design Ltd | Professional & scientific | 2021 |
| First Choice Maintenance Southeast Limited | Construction | 2026 |
| First Freight Direct Limited | Transport & logistics | 2004 |
| First Green Steps Ltd | Professional & scientific | 2021 |
| First Hydrogen Limited | Professional & scientific | 2021 |
| First Infosec Limited | Information & communication | 2009 |
| First Look Limited | Information & communication | 2018 |
| Fishon Tackle Shop Limited | Wholesale & retail | 2018 |
| Fit Feet Podiatry Ltd | Health & social care | 2022 |
| Fitzrovia Analytics Limited | Financial services | 2016 |
| Five Dollar Shake Limited | Manufacturing | 2002 |
| Five Oak Green Garage Limited | Wholesale & retail | 2023 |
| Five Oak Green Test Centre Limited | Professional & scientific | 2019 |
| Five Oak Store Limited | Wholesale & retail | 2017 |
| Fiveoak Surfacing Ltd | Administrative & support | 2024 |
| FIX Factory Automotive Limited | Wholesale & retail | 2025 |
| Fixed Electrical Services Ltd | Construction | 2019 |
| FJE Electrical Services Limited | Energy | 2017 |
| FKA Brands Limited | Wholesale & retail | 2002 |
| FL430 Limited | Professional & scientific | 2016 |
| Flamebreak International Limited | Construction | 2021 |
| Flaming Aura Limited | Wholesale & retail | 1999 |
| Flare Systems Limited | Construction | 2016 |
| Flash Mobile Welding Services Limited | Construction | 2011 |
| Flash Plant Hire Limited | Construction | 2023 |
| Flavo Tonbridge Ltd | Hospitality | 2025 |
| Flechazul Limited | Financial services | 1993 |
| Fleet House Management (Upnor) Ltd | Real estate | 2025 |
| Fleet Technology Limited | Professional & scientific | 2006 |
| Fleettracking.Co.Uk Ltd | Other services | 2012 |
| Fleetwood Forest Products Limited | Administrative & support | 1988 |
| Fletcher Smith Marketing and Communications Limited | Administrative & support | 2011 |
| Flightshott Farm Limited | Agriculture & fishing | 1951 |
| Flishinghurst Consulting Limited | Professional & scientific | 2016 |
| Flix Premiere Limited | Information & communication | 2015 |
| Florio Holdings Limited | Real estate | 2023 |
| Flossie Limited | Real estate | 2001 |
| Flourish People Ltd | Professional & scientific | 2017 |
| FLW Limited | Construction | 2018 |
| Flyer Food Limited | Hospitality | 2023 |
| Flying EMU Studios Ltd | Information & communication | 2025 |
| Flysch Ltd | Extraterritorial | 2025 |
| FM Financial Solutions Limited | Financial services | 2011 |
| Fmaaf Limited | Administrative & support | 2001 |
| Foalhurst Letting Limited | Real estate | 2025 |
| Folly Properties Limited | Real estate | 2010 |
| Food 4 Healthy Guts Limited | Wholesale & retail | 2026 |
| Food Xpert Limited | Hospitality | 2022 |
| Fools Limited | Professional & scientific | 2010 |
| Footsteps Dance & Fitness Ltd | Arts & recreation | 2021 |
| Footsteps Performance Academy Ltd | Arts & recreation | 2025 |
| Ford Trading Ltd | Wholesale & retail | 2026 |
| Ford Y. & C. Model Register Limited | Arts & recreation | 2002 |
| Foreground Media Ltd | Information & communication | 2019 |
| Forest Farm Services Limited | Extraterritorial | 2002 |
| Forest Garden Shovelstrode Ltd | Hospitality | 2010 |
| Forever Green Sun Ltd | Energy | 2015 |
| Forever Young International Ltd | Health & social care | 1998 |
| Forever ZEN TCM Ltd | Administrative & support | 2016 |
| Forge Consulting Limited | Wholesale & retail | 1982 |
| Forge House (Kent) LLP | | 2017 |
| Forgemaster Miniatures Limited | Manufacturing | 2022 |
| Forget ME NOT Services C.I.C. | Health & social care | 2020 |
| Formalgood Property Management Limited | Households | 1998 |
| Forsback Ltd | Administrative & support | 2022 |
| Forte Music WOK Ltd. | Education | 2018 |
| Fortis Medical Limited | Health & social care | 2010 |
| Fortitude Academy LLP | | 2012 |
| Fortitude Legacy LLP | | 2020 |
| Fortitude Limited | Arts & recreation | 2006 |
| Fortius IT Solutions Limited | Information & communication | 2023 |
| Fortrix Integrated Systems Ltd | Construction | 2026 |
| Forum Ltd | Real estate | 2004 |
| Foster & Birchall Limited | Real estate | 2015 |
| Foster Powell (Milford Haven) Limited | Real estate | 1949 |
| Founder Clothing Ltd | Wholesale & retail | 2016 |
| Fountainview Enterprises Limited | Real estate | 1995 |
| Four Seasons Gardens Limited | Administrative & support | 2009 |
| Four Seasons Tennis Court Maintenance Limited | Administrative & support | 2016 |
| FOX Griffin Limited | Administrative & support | 2016 |
| FOX Manning Group Ltd | Professional & scientific | 2019 |
| FOX Run Management Company Limited | Households | 2014 |
| Fox-Groves Architecture Ltd | Professional & scientific | 2021 |
| Foxpool Property Co. Limited | Hospitality | 1966 |
| Foxy Media Limited | Information & communication | 2012 |
| FP Innovations Limited | Administrative & support | 2004 |
| FR Automotive & Recovery Ltd | Wholesale & retail | 2021 |
| Fractional Engagements Ltd | Administrative & support | 2025 |
| Frame Management Ltd | Professional & scientific | 2020 |
| Frame One Television Limited | Arts & recreation | 2004 |