| Favours Technologies Ltd | Other services | 2025 |
| Fawzia Limited | Health & social care | 2024 |
| FC Air Conditioning UK Ltd | Construction | 2025 |
| FC Poon Limited | Health & social care | 2019 |
| FD Financing Ltd | Administrative & support | 2017 |
| FDV Leigh Ltd | Hospitality | 2024 |
| Featherblade Limited | Hospitality | 2019 |
| Feefa Football Academy Limited | Other services | 2019 |
| FEELWELL360 Ltd | Health & social care | 2020 |
| Felixstowe Properties Limited | Other services | 1996 |
| Fence 4 U Ltd | Construction | 2026 |
| Fenland Decorators Limited | Construction | 2024 |
| Feral Fine Arts Ltd | Wholesale & retail | 2023 |
| Ferdinando Communications Ltd | Professional & scientific | 2022 |
| Fernandes of Leigh Limited | Construction | 2024 |
| Ferrand Transport Limited | Transport & logistics | 2005 |
| FFP Technology Ltd | Extraterritorial | 2023 |
| FHE Services Limited | Education | 2016 |
| FI Fit Design Ltd | Construction | 2021 |
| Fibre Network Design Ltd | Construction | 2019 |
| Fielding Consulting Limited | Information & communication | 2018 |
| Fielding Transport (Grays) Limited | Other services | 2001 |
| Fierce Gym Ltd | Arts & recreation | 2019 |
| Fifteen Twenty-One Limited | Real estate | 2026 |
| FIG Tree Health & Nutrition Ltd | Health & social care | 2024 |
| Figg Property Limited | Real estate | 2018 |
| FIL Euro Nation Select Ltd | Wholesale & retail | 2025 |
| Financial Solutions SC Limited | Financial services | 2008 |
| Finantrade Limited | Financial services | 2026 |
| Findlay Communication Services Limited | Other services | 1996 |
| Finwood Homes Ltd | Real estate | 2017 |
| Fiona's Beauty Studio Ltd | Other services | 2018 |
| Fiona's Hollistic Ltd | Health & social care | 2018 |
| Fire Business Services Limited | Professional & scientific | 2013 |
| Fire Engineer Go Limited | Information & communication | 2026 |
| Fire Maintenance Ltd | Professional & scientific | 2002 |
| First Environmental Services Limited | Construction | 2013 |
| First FIX GAS Services Limited | Construction | 2018 |
| First in Last OUT Touring Limited | Arts & recreation | 2022 |
| Firstone Europe Limited | Wholesale & retail | 2024 |
| Firstrate Care Services Limited | Health & social care | 2022 |
| Fiscal Matters Ltd | Construction | 2023 |
| Fish Express Essex Limited | Hospitality | 2016 |
| Fish to Go Limited | Real estate | 2005 |
| Fishalicious Leigh Ltd | Hospitality | 2023 |
| Fisher Estates (Lettings) Ltd | Real estate | 2021 |
| Fisher Estates (Sales) Limited | Real estate | 2024 |
| Fisher Properties SWF Ltd | Real estate | 2024 |
| Fisher Property Services Ltd | Construction | 2018 |
| Fishfingersorlobster Ltd | Information & communication | 2015 |
| Fishinity Pro Ltd | Agriculture & fishing | 2025 |
| Fitness With Lianne Ltd | Other services | 2023 |
| Fitout + Build Limited | Construction | 2024 |
| Fitzrovia Post Limited | Information & communication | 1999 |
| Five Point Building Services Limited | Construction | 2026 |
| Fixafault Electrical Limited | Construction | 2025 |
| Fizzii Property and Estates Management Limited | Real estate | 2024 |
| FJ Creative Limited | Information & communication | 2016 |
| FJB K9 Limited | Other services | 2025 |
| FJT Furnishing for Landlords Ltd | Real estate | 2022 |
| Flamingo Fire Protection Ltd | Public administration | 2019 |
| Flash Health Limited | Information & communication | 2021 |
| Flashing Forward Limited | Administrative & support | 2022 |
| Flashman Estates Limited | Real estate | 2023 |
| Flavours Gelato Eastwood Ltd | Manufacturing | 2022 |
| Flayosc Property Limited | Professional & scientific | 1995 |
| Fletcher Locations Limited | Information & communication | 2026 |
| Fleur Couture (London) Limited | Wholesale & retail | 2012 |
| Fleur Couture by Lisa Angelina Ltd | Wholesale & retail | 2020 |
| Flewers Drylining Ltd | Construction | 2018 |
| Flexman Lane Limited | Professional & scientific | 2001 |
| Flight Timber Products Limited | Manufacturing | 1992 |
| Flint Building & Construction Limited | Other services | 2001 |
| Flinton Blythe Limited | Real estate | 2018 |
| Flitch Holdings Limited | Administrative & support | 2019 |
| FLO Residential Ltd | Real estate | 2021 |
| Floodwall Ltd | Other services | 2019 |
| Floorcharts Limited | Information & communication | 2022 |
| Flora & Sketch Limited | Arts & recreation | 2023 |
| Florence and Belles Limited | Real estate | 2025 |
| Flour and Spoon Ltd | Wholesale & retail | 2018 |
| Flourish Career Coaching Ltd | Administrative & support | 2024 |
| Fluent Services Limited | Construction | 2026 |
| FLY Altiro Ltd | Transport & logistics | 2026 |
| Flybooks Publishing and Media Ltd | Information & communication | 2023 |
| FM Amplify Ltd | Professional & scientific | 2026 |
| Foam and Covers Ltd | Other services | 2020 |
| FOCUS7 International Ltd | Professional & scientific | 2015 |
| Foden Baynes Associates Limited | Financial services | 2000 |
| Fofa Creative Ltd | Administrative & support | 2019 |
| Fogarty Construction Ltd | Construction | 2024 |
| Folded Wing Ltd | Information & communication | 2006 |
| Food at Number Forty Ltd | Manufacturing | 2021 |
| Forensic Cost Accounting Limited | Professional & scientific | 2016 |
| Foresight Commerce Limited | Wholesale & retail | 2021 |
| Forge Advisors Limited | Professional & scientific | 2025 |
| Forge Stores Canewdon Ltd | Wholesale & retail | 2015 |
| Forgeme Ltd | Wholesale & retail | 2025 |
| Foro Tech Ltd | Information & communication | 2016 |
| Forrest & Rose Interiors Ltd | Construction | 2024 |