| First Escape Systems Limited | Construction | 2017 |
| First Gear Properties Ltd | Real estate | 2018 |
| First Glass Installations Ltd | Construction | 2021 |
| First Quay Ltd | Construction | 2002 |
| First Source Property Investments Ltd | Real estate | 2023 |
| First Step Opportunity Group | Education | 2003 |
| First Steps Future Will Planning Ltd | Other services | 2024 |
| First Touch Sport Ltd | Arts & recreation | 2019 |
| Firstford (Sales) Limited | Extraterritorial | 1993 |
| Firstford (Services) Limited | Extraterritorial | 1993 |
| Firstford Limited | Administrative & support | 1984 |
| Firstoutlook Limited | Transport & logistics | 2023 |
| Fish 123 Limited | Hospitality | 2019 |
| Fitforce-London Ltd | Arts & recreation | 2016 |
| Fitness BBA Ltd | Wholesale & retail | 2020 |
| Fitnesshall Ltd | Arts & recreation | 2026 |
| Five Arrows Cars Limited | Wholesale & retail | 2019 |
| Five Star Stitches Limited | Other services | 2023 |
| Fixation Surface Repair Specialists Limited | Construction | 2016 |
| Fjas Homes Ltd | Real estate | 2025 |
| Fleetwise Compliance Solutions Limited | Professional & scientific | 2025 |
| Fletchers Pallets Limited | Manufacturing | 1997 |
| Flexmind Strategies Ltd | Professional & scientific | 2022 |
| Flintcom Ltd | Manufacturing | 2008 |
| Flipwise Properties Limited | Real estate | 2025 |
| FLO 2 Ltd | Manufacturing | 2017 |
| FLO Bayley Limited | Professional & scientific | 2005 |
| Flomax Finishings Ltd | Construction | 2016 |
| Flood & Civil Ltd | Professional & scientific | 2018 |
| Floormatt Limited | Construction | 2015 |
| Floufitness Limited | Manufacturing | 2024 |
| Flourishing Conversations Ltd | Administrative & support | 2026 |
| Flow Direct Plumbing and Heating Supplies Ltd | Construction | 2014 |
| Flowers by Cassie Limited | Wholesale & retail | 2023 |
| Flowery Candy Floss Ltd | Manufacturing | 2023 |
| Fluffy Lashes Ltd | Other services | 2024 |
| Fluid Senses Ltd | Information & communication | 2015 |
| Flux Prefabrication Limited | Construction | 2023 |
| Fluxter Limited | Information & communication | 2021 |
| Flynn & Co Construction Ltd | Construction | 2021 |
| FMF Capital Limited | Real estate | 2018 |
| FMU Vehicle Rental Ltd | Wholesale & retail | 2025 |
| Focus Music Agency Ltd | Education | 2023 |
| Focus Sports Global Ltd | Wholesale & retail | 2026 |
| Fogsim Ltd | Information & communication | 2021 |
| Fontanile Ltd | Professional & scientific | 2025 |
| Food and Events London Ltd | Hospitality | 2025 |
| Food and Wine Wingletye Ltd | Wholesale & retail | 2024 |
| Food Exchange Limited | Wholesale & retail | 2023 |
| Food Glorious Food (London) Ltd | Hospitality | 2020 |
| Football Card Exchange Limited | Wholesale & retail | 2025 |
| Fordham Henderson Consulting Ltd | Professional & scientific | 2016 |
| Foreman Electrical Services Ltd | Manufacturing | 2003 |
| Forest Group Assets Limited | Administrative & support | 2026 |
| Forest Hydraulics (Holdings) Limited | Financial services | 2023 |
| Forest Hydraulics Limited | Extraterritorial | 2024 |
| Forest Joinery and Carpentry Limited | Manufacturing | 2021 |
| Foreuk Limited | Administrative & support | 2021 |
| Forever Famous Entertainment Limited | Information & communication | 2025 |
| Forget-Me-Not Nursery Limited | Education | 2014 |
| Fornace Limited | Construction | 2024 |
| Fortis Estate Holdings Ltd | Real estate | 2019 |
| Fortitech Solutions Limited | Construction | 2025 |
| Fortranix Limited | Information & communication | 2018 |
| Fortuno Holdings Limited | Financial services | 2025 |
| Fortuno Investments Limited | Financial services | 2025 |
| Forward Analytics Group Limited | Information & communication | 2025 |
| Foss Accounting Limited | Professional & scientific | 2009 |
| Foster Studios Ltd | Arts & recreation | 2019 |
| Fountain Global Limited | Construction | 2018 |
| Four Season Publishing Ltd | Manufacturing | 2019 |
| Four Way Global Trading Limited | Wholesale & retail | 2020 |
| Foxmor Ltd | Real estate | 2024 |
| Fragrance by Ayah Limited | Wholesale & retail | 2023 |
| Franck Services Limited | Construction | 2025 |
| Frank Real Estate Service Limited | Real estate | 2011 |
| Franklin Scott Mechanical Ltd | Construction | 2016 |
| Frederick Budd & Co Limited | Professional & scientific | 2009 |
| Fredericks Groundworks Ltd | Construction | 2025 |
| Freeform Jewellery Limited | Wholesale & retail | 2019 |
| Freeholder Limited | Real estate | 2019 |
| Freeman P Limited | Wholesale & retail | 2019 |
| Freesley Solutions Ltd | Professional & scientific | 2016 |
| Fresh Choice Catering Ltd | Hospitality | 2013 |
| Fresh From Farm Ltd | Wholesale & retail | 2012 |
| Fresh Import Ltd | Wholesale & retail | 2016 |
| Fresh Wharf Estates Limited | Real estate | 1928 |
| Fresh Wharf Holdings Limited | Real estate | 2004 |
| Fresh Wharf IOW Ltd | Real estate | 2021 |
| Fresh Wharf Leeds Limited | Real estate | 2022 |
| Fresh Wharf Manchester Limited | Real estate | 2024 |
| Fridge Space Limited | Hospitality | 2024 |
| Fried Chicken Hornchurch Ltd | Hospitality | 2026 |
| Friends Property Essex Limited | Construction | 2025 |
| FRM Decor Ltd | Construction | 2025 |
| Frog Technologies U.K. Limited | Information & communication | 2020 |
| Fryclean Limited | Wholesale & retail | 2011 |
| FS Chauffeur Limited | Transport & logistics | 2025 |
| FSA Homes Ltd | Real estate | 2024 |
| Fsms Property Limited | Real estate | 2025 |