| Figureneat Limited | Real estate | 1994 |
| File Focus Limited | Extraterritorial | 2013 |
| Film and Visual Ltd | Professional & scientific | 2016 |
| Film Unit Signs Limited | Administrative & support | 2024 |
| Filmstro Holdings Limited | Information & communication | 2016 |
| Filmstro Limited | Information & communication | 2014 |
| Filton Brewery Products Limited | Manufacturing | 1990 |
| Filuda Limited | Financial services | 2017 |
| Finalhit Limited | Information & communication | 2001 |
| Finch Hotels Limited | Hospitality | 2012 |
| Finchley Management (Langney) Limited | Households | 2020 |
| Findon Dental Clinic Ltd | Health & social care | 2022 |
| Fine Indian (Eastbourne) Ltd | Hospitality | 2019 |
| Fineshine Cleaning Services Limited | Administrative & support | 2019 |
| Finest Gifts Solutions Ltd | Wholesale & retail | 2019 |
| Finnis Planning Ltd | Professional & scientific | 2020 |
| Fiona Norwood Ltd | Health & social care | 2014 |
| Fire Door Solutions Group Limited | Construction | 2025 |
| Fire Protection Limited | Manufacturing | 1994 |
| Fire Security and Electrical Solutions Limited | Administrative & support | 2011 |
| Firebrand Design Limited | Other services | 1993 |
| Fireflies Childcare Limited | Health & social care | 2021 |
| Firerisk Control Solutions Ltd | Construction | 2017 |
| Firespray International Limited | Construction | 1996 |
| Firestorm Filtration Limited | Construction | 2007 |
| First Aqua Limited | Health & social care | 2018 |
| First Avenue Lifestyle Limited | Real estate | 2015 |
| First Choice Dental Clinic Limited | Health & social care | 2009 |
| First Line Staffing Ltd | Health & social care | 2024 |
| First Response Learning Limited | Education | 2008 |
| Firstrock Investments Limited | Real estate | 2020 |
| Fish and Meat Limited | Hospitality | 2015 |
| Fisherman's Village Estate Limited | Extraterritorial | 2001 |
| Fishora Ltd | Wholesale & retail | 2026 |
| Fitness Icons Ltd | Education | 2025 |
| Fitton Family Company Ltd | Hospitality | 2021 |
| Fitzmaurice Developments Limited | Real estate | 2003 |
| Fitzrovia Services Limited | Professional & scientific | 2015 |
| Five Gables Security Limited | Administrative & support | 2018 |
| FKD Drive Ltd | Transport & logistics | 2018 |
| FL Fitness Limited | Arts & recreation | 2017 |
| Flamingo Financial Limited | Financial services | 2018 |
| Flanway Ltd | Construction | 2015 |
| Flare Detailing Ltd | Wholesale & retail | 2024 |
| Flat 2 30 South Street Ltd | Real estate | 2026 |
| Flats 18 - 21, 1 Lake Drive RTM Company Limited | Households | 2015 |
| Flavour Maker Limited | Manufacturing | 2017 |
| Flavusia Ltd | Administrative & support | 2024 |
| Fleet Resourcing Limited | Wholesale & retail | 1999 |
| Flevsoye Ventures Limited | Health & social care | 2016 |
| Flexcy Logistics Ltd | Wholesale & retail | 2026 |
| Flight Investments (UK) Limited | Financial services | 2000 |
| Flight Sport Aviation LLP | | 2024 |
| Flint (Southern) Limited | Wholesale & retail | 2003 |
| Flint Halls (Eastbourne) Limited | Households | 2002 |
| FLO Limited | Other services | 2001 |
| Flogs Fungi Ltd | Agriculture & fishing | 2021 |
| Flokleen Limited | Manufacturing | 2002 |
| Flomar Garage Limited | Wholesale & retail | 2011 |
| Floral Event Design Ltd | Other services | 2022 |
| Florian Motors Limited | Wholesale & retail | 2018 |
| Flour Flow Ltd | Hospitality | 2019 |
| Flourishing Futures Psychology Limited | Health & social care | 2025 |
| Flowpump Engineering Limited | Manufacturing | 2025 |
| FLT Investments Limited | Real estate | 2019 |
| Flying Colours Motorcycle Training Ltd | Education | 2007 |
| Flying Fish Learning Ltd | Professional & scientific | 2018 |
| Flyr Limited | Wholesale & retail | 2018 |
| FM 247 Ltd | Administrative & support | 2025 |
| FM Dental Limited | Health & social care | 2016 |
| FM Plumbing & Heating Limited | Construction | 2015 |
| FMA Media Ltd | Information & communication | 2017 |
| FML Investments Limited | Real estate | 2012 |
| FMR (UK) Ltd | Administrative & support | 2006 |
| FMR Dental Training Ltd | Professional & scientific | 2021 |
| Fmss Limited | Administrative & support | 2020 |
| Fnaf Holdings Limited | Financial services | 2026 |
| FO Future Properties Ltd | Real estate | 2022 |
| Focus Property Services Limited | Real estate | 1987 |
| Focus Wealth Ltd | Professional & scientific | 2015 |
| Folio Accounting Services Limited | Professional & scientific | 2014 |
| Fomtec UK Limited | Manufacturing | 2004 |
| Fonetastic Limited | Wholesale & retail | 2009 |
| Fonseca Pereira & Mendes Limited | Other services | 2016 |
| Fontaine Decorative Limited | Wholesale & retail | 2014 |
| Fontelina Ltd | Financial services | 2025 |
| Food and Drink Wholesale UK Ltd | Other services | 2024 |
| Foodex Ltd | Wholesale & retail | 2019 |
| Foodoasis Ltd | Hospitality | 2025 |
| Foods Direct Limited | Manufacturing | 2016 |
| Foodstar KJ Ltd | Hospitality | 2017 |
| Football Belts Limited | Extraterritorial | 2020 |
| Footprint Sports and Entertainment Limited | Professional & scientific | 2015 |
| FOR Art's Sake Limited | Arts & recreation | 2022 |
| FOR Veteran and Vintage Ltd | Professional & scientific | 2016 |
| FOR Your Fries Only Ltd | Hospitality | 2025 |
| Ford Waste Recycling Solutions Ltd | Extraterritorial | 2018 |
| Fordaskip Limited | Water & waste | 2023 |
| Fordbourne Limited | Real estate | 2020 |
| Forest Crown Group Limited | Wholesale & retail | 2026 |