| Filmday Management Limited | Real estate | 2005 |
| FIN IP Limited | Professional & scientific | 2023 |
| Finanalytica Solutions Limited | Extraterritorial | 2018 |
| Finance Change Advisory Limited | Information & communication | 2018 |
| Finance UK Properties Limited | Financial services | 2023 |
| Financial Analysts Limited | Professional & scientific | 2001 |
| Financial and Energy Consultancy Ltd | Financial services | 2025 |
| Finch Manor (Holdings) Limited | Real estate | 2003 |
| Finforte Limited | Information & communication | 2014 |
| Finger Clear Limited | Administrative & support | 2010 |
| Finsbury Limited | Real estate | 2015 |
| Fintech Enterprises Ltd | Professional & scientific | 2015 |
| Fintech Pundits Ltd | Information & communication | 2020 |
| Fintecheduai Ltd | Education | 2025 |
| Fintricity Group Limited | Information & communication | 2011 |
| Finwiz Consultants Limited | Professional & scientific | 2025 |
| Fiqtion One Ltd | Information & communication | 2023 |
| Firmus Heat Limited | Construction | 2011 |
| Firs Walk (Northwood) Developments Ltd | Real estate | 2021 |
| Firs Walk (Northwood) Ltd | Real estate | 2021 |
| First Choice Mobile Cleaning Limited | Other services | 2025 |
| First Choice Packing Limited | Administrative & support | 2020 |
| First Choice R.T.S Limited | Transport & logistics | 2022 |
| First Class Autocare Ltd | Wholesale & retail | 2026 |
| First Class Learning Harrow Weald Limited | Education | 2024 |
| First GP Limited | Health & social care | 2019 |
| First Person Communications Ltd | Professional & scientific | 2019 |
| First Prosperity Ltd | Real estate | 2023 |
| Firstnet Limited | Professional & scientific | 2022 |
| Firststart Limited | Real estate | 2013 |
| Fisher Property Solutions Limited | Professional & scientific | 2013 |
| Fishes & Dishes Limited | Wholesale & retail | 2002 |
| Fit N Fast Limited | Administrative & support | 2018 |
| Fitting Edge Ltd | Construction | 2025 |
| Fitzgerald House Management Limited | Real estate | 2016 |
| Fitzroy Court (Shepherd's Hill) Limited | Real estate | 1964 |
| Five Healthgroup Limited | Health & social care | 2020 |
| Five Leaves London PVT Ltd | Wholesale & retail | 2020 |
| Five RAI Investments Ltd | Real estate | 2017 |
| Fivecrest Limited | Construction | 1983 |
| Fivek Traders Ltd | Wholesale & retail | 2019 |
| Flagship (Dorset) Ltd | Wholesale & retail | 2008 |
| Flaherty Builders Ltd | Construction | 2014 |
| Flair With Pride Limited | Other services | 2005 |
| Flambard Homes Limited | Construction | 2023 |
| Flash 24 Properties Ltd | Real estate | 2021 |
| Fleur Trossel Limited | Arts & recreation | 2024 |
| Flexhill Networks Limited | Construction | 2011 |
| Flightcare Limited | Health & social care | 1991 |
| Flo&Construction Ltd | Construction | 2019 |
| Flo-Decor Ltd | Manufacturing | 2026 |
| Float That Limited | Manufacturing | 2023 |
| Flonax Ltd | Transport & logistics | 2026 |
| Flow & FIX Ltd | Construction | 2023 |
| Flow With Faye Ltd | Administrative & support | 2026 |
| Flowgain Ltd | Wholesale & retail | 2021 |
| Fluent in Maths (UK) Ltd | Education | 2023 |
| Fluxus Leisure Limited | Arts & recreation | 2019 |
| Fluxus Retreats Limited | Administrative & support | 2021 |
| FM Photography Ltd | Professional & scientific | 2018 |
| FNL Properties Limited | Real estate | 2020 |
| Focus Building Group Ltd | Professional & scientific | 2013 |
| Focus Building Solutions Limited | Construction | 2010 |
| Focus Developments Solutions 2014 Ltd | Construction | 2013 |
| Focus Developments Solutions Ltd | Construction | 2018 |
| Focused Sales Marketing Limited | Administrative & support | 2001 |
| Focusinvest Ltd | Real estate | 2019 |
| FOCUSPOINT1 Ltd | Information & communication | 2015 |
| Fontain Property Ltd | Real estate | 2014 |
| Foodiewuwdies Limited | Wholesale & retail | 2013 |
| Forbes Fitness Limited | Arts & recreation | 2016 |
| Force Velocity Group Ltd | Arts & recreation | 2020 |
| Forest Fields Investments Limited | Real estate | 2025 |
| Formworks VC Limited | Financial services | 2025 |
| Fortius Business Solutions Limited | Professional & scientific | 2021 |
| Fortuna (Pinner) Ltd | Professional & scientific | 2024 |
| Fortunaa Limited | Health & social care | 2025 |
| Fortune Fusion Ltd | Hospitality | 2025 |
| Fortune Tangerine Ltd | Wholesale & retail | 2025 |
| Fortyfull Investments Limited | Real estate | 1963 |
| Fotofranchise Limited | Manufacturing | 2023 |
| Fototyne Limited | Manufacturing | 2026 |
| Fotovision Limited | Manufacturing | 2024 |
| Founder.Careers Limited | Administrative & support | 2024 |
| Fountainhead Creative Consultants Limited | Administrative & support | 2002 |
| Four Barrels Ltd | Hospitality | 2011 |
| Four Columns Coaching and Consultancy Ltd | Professional & scientific | 2023 |
| Fourth Way Ltd | Real estate | 2021 |
| Fourth Way Road Limited | Wholesale & retail | 2014 |
| FP Advising Ltd | Information & communication | 2021 |
| FPK Car Hire Limited | Administrative & support | 2023 |
| Fpna Consultancy Limited | Professional & scientific | 2022 |
| FPS Nominees Limited | Administrative & support | 2012 |
| FQ IT Consultancy Ltd | Information & communication | 2016 |
| Fractal Design & Technology Limited | Information & communication | 2002 |
| Fractal Wings Limited | Professional & scientific | 2017 |
| Fractional Sales Global Ltd | Professional & scientific | 2025 |
| Fractured Pictures Ltd | Arts & recreation | 2014 |
| Frameplay Limited | Administrative & support | 2007 |
| Frampton Cooking Systems Limited | Manufacturing | 1997 |