| Finisterre One Limited | Financial services | 2019 |
| Fiona Brown Design Ltd | Professional & scientific | 2026 |
| Fire & Smoke UK Limited | Construction | 2015 |
| Fire Doors London Ltd | Construction | 2022 |
| Fire Stopping London Ltd | Other services | 2020 |
| Fireaway (Loughton) Limited | Hospitality | 2019 |
| First & Best Travel Ltd | Administrative & support | 2025 |
| First Contact Electrics Limited | Construction | 2009 |
| First for Party Wall Surveyors (Cambridge) Limited | Professional & scientific | 2017 |
| First Forensic Services Limited | Administrative & support | 2005 |
| First Hazelwood Management Company Limited | Households | 1981 |
| First Universal Care Ltd | Health & social care | 2012 |
| First Walton Lodge Management Company Limited | Real estate | 1991 |
| Firstserve IT Services Ltd | Information & communication | 2015 |
| Fitfam Studios Limited | Arts & recreation | 2017 |
| Fitness Therapy Limited | Arts & recreation | 2013 |
| Five Oaks Land Ltd. | Real estate | 1997 |
| Five Star Auto Sales Ltd | Wholesale & retail | 2018 |
| FIX IT Express Ltd | Transport & logistics | 2023 |
| FIX IT Services Ltd | Wholesale & retail | 2018 |
| Fixall Plant Sales and Repairs Limited | Manufacturing | 2020 |
| Fixit 4 U Limited | Manufacturing | 2005 |
| Fixtrade Limited | Professional & scientific | 2011 |
| Fixxd Heating Services Limited | Construction | 2025 |
| Flair Business Psychology Ltd | Professional & scientific | 2018 |
| Flat 3 Dunford Court Developments Limited | Administrative & support | 2008 |
| Flavour Neighbours Limited | Manufacturing | 2019 |
| Flex Workspace Marketing Ltd | Information & communication | 2026 |
| Flexwood Joinery Limited | Administrative & support | 2011 |
| Flint Property Development Ltd | Construction | 2018 |
| Flipiripi Ltd | Real estate | 2025 |
| Florence LES Arts DE LA Table Ltd | Wholesale & retail | 2023 |
| Florence Street Management Limited | Households | 1990 |
| Flori Estates Ltd | Real estate | 2025 |
| Flori Smile Limited | Education | 2020 |
| Flori Training Ltd | Construction | 2022 |
| Florian Chimney Services Ltd | Administrative & support | 2026 |
| Florindoru Ltd | Hospitality | 2026 |
| Floriography Studio Limited | Wholesale & retail | 2025 |
| FLY High Consulting Limited | Information & communication | 2014 |
| Flying Colours Group Limited | Arts & recreation | 1995 |
| Flying Shoe Films Ltd | Arts & recreation | 2017 |
| FM Construction Ltd | Construction | 2016 |
| FM Lounge Ltd | Hospitality | 2018 |
| Focus Impact Ltd | Information & communication | 2026 |
| Folan Masonry Consultants Limited | Professional & scientific | 2016 |
| Folha Seca Ltd. | Professional & scientific | 2012 |
| Follons Ltd | Hospitality | 2025 |
| Football Taverns Ltd | Hospitality | 2020 |
| Forbes Social Care Ltd | Health & social care | 2024 |
| Force 1 Management Ltd | Arts & recreation | 2011 |
| Force Recovery Limited | Transport & logistics | 2017 |
| Forest Building Development & Property LLP | | 2009 |
| Forest Estates London Limited | Construction | 2021 |
| Forest LEA Properties Limited | Households | 1993 |
| Forest Learning LP | | 2023 |
| Foresters Court Property Management Limited | Households | 2024 |
| Forever Vitality Limited | Wholesale & retail | 2018 |
| Forevergreen Homes&Gardens Ltd | Administrative & support | 2024 |
| Forge Three Ltd | Information & communication | 2025 |
| Forma Structures Ltd | Professional & scientific | 2025 |
| Former Glory Footwear Ltd | Administrative & support | 2019 |
| Formula Taxis Limited | Transport & logistics | 2026 |
| Fortis Green Mews Ltd | Real estate | 2022 |
| Fortuna Property Developments Limited | Construction | 2025 |
| Forward Thinking Personnel Ltd | Administrative & support | 2014 |
| Fountain Mechanical Services Limited | Construction | 2026 |
| Four Acres GC Ltd | Construction | 2025 |
| Four Elements Pilates Ltd | Arts & recreation | 2025 |
| Four Pillar Developments Ltd | Real estate | 2026 |
| Four Seasons Cooling Ltd | Construction | 2021 |
| Four Seasons Management Limited | Real estate | 2020 |
| FOX Electrical Install Limited | Energy | 2015 |
| FOX Foods (UK) Limited | Wholesale & retail | 2006 |
| FOX Visual Systems Ltd | Extraterritorial | 2009 |
| Foxchen Group Ltd | Administrative & support | 2025 |
| Frames of London Ltd | Wholesale & retail | 2014 |
| Francesca Beau Ltd | Wholesale & retail | 2014 |
| Franks Black Taxi Ltd | Transport & logistics | 2025 |
| Fraser & Holmes Fresh Produce Ltd | Wholesale & retail | 2026 |
| Fraser Group Management Limited | Real estate | 2020 |
| Freckle & BOW Creative Ltd | Professional & scientific | 2025 |
| Freedman Investments Limited | Professional & scientific | 2008 |
| French TIP Ltd | Other services | 2018 |
| Fresh Air Consultancy Ltd | Professional & scientific | 2026 |
| Fresh Light Limited | Information & communication | 2014 |
| Fresh Start Gardening Ltd | Administrative & support | 2025 |
| Fresh VEG & Fruit Limited | Administrative & support | 2016 |
| Freshplant Limited | Construction | 2006 |
| Freshwater Films Limited | Information & communication | 2011 |
| Freya Lodge Residents Management Limited | Households | 2025 |
| Friars Developments (Opco) Limited | Administrative & support | 2024 |
| Friars Developments Limited | Administrative & support | 2011 |
| Fricative Limited | Administrative & support | 2022 |
| Friday Feeling Limited | Professional & scientific | 2021 |
| Friends K Limited | Wholesale & retail | 2011 |
| FRJ Roofing Limited | Construction | 2025 |
| Froggii Ltd | Professional & scientific | 2019 |
| Front Edge Accountants Ltd | Other services | 2012 |
| Front Technologies Ltd | Professional & scientific | 2020 |