| Find a Property Limited | Real estate | 2015 |
| Fine Foods Direct Limited | Professional & scientific | 1970 |
| Finers Accountancy Limited | Professional & scientific | 2019 |
| Finnocon Services Limited | Construction | 2013 |
| Finpact Services Limited | Professional & scientific | 2021 |
| Finsalento Ltd | Financial services | 2019 |
| Fintegration Limited | Information & communication | 2008 |
| Fiona Gatty Limited | Professional & scientific | 2007 |
| Fire Concern Limited | Manufacturing | 2013 |
| Fire Safe Windows and Doors Ltd | Construction | 2020 |
| Firestar Promotions Ltd | Wholesale & retail | 2024 |
| Firestar Toys Ltd | Wholesale & retail | 2005 |
| Firm Partners Ltd | Administrative & support | 2010 |
| First Avenue Tech Ltd | Information & communication | 2022 |
| First Centre Ltd | Wholesale & retail | 2019 |
| First Class Building Ltd | Construction | 2021 |
| First Financial Intermediaries Limited | Financial services | 2000 |
| First Financial London Intermediaries Ltd | Financial services | 2020 |
| First Flexserv Limited | Professional & scientific | 2025 |
| First Health London Ltd | Financial services | 2024 |
| First Heritage Global Services Ltd | Administrative & support | 2021 |
| First Recycling Limited | Water & waste | 2026 |
| First Steps (London) Limited | Education | 2003 |
| First Track Investment Ltd | Real estate | 2022 |
| FIRST1ONE Hair & Beauty Ltd | Other services | 2021 |
| Firstcure Limited | Health & social care | 2021 |
| Fisca Ltd | Wholesale & retail | 2016 |
| Fisca Plumbing and Heating Limited | Construction | 2019 |
| Fish Shop Ltd | Hospitality | 2025 |
| Fisher Packman & Associates Limited | Professional & scientific | 2007 |
| Fison Investment Limited | Real estate | 2017 |
| Fit Garage Ltd | Wholesale & retail | 2023 |
| Fitex Services Limited | Manufacturing | 2019 |
| Fitpaq Ltd | Information & communication | 2013 |
| Fits Textiles Limited | Manufacturing | 2024 |
| Five D Solutions Ltd | Professional & scientific | 2018 |
| Five Health Ltd | Other services | 2023 |
| Fivejays Properties Limited | Real estate | 2016 |
| Fixter Inc Ltd | Professional & scientific | 2022 |
| Fl.C. (UK) Limited | Wholesale & retail | 2010 |
| Flag Property Limited | Wholesale & retail | 2014 |
| Flamingo Blinds & Awnings Ltd | Wholesale & retail | 2019 |
| Flat 2 Burley House Ltd | Real estate | 2024 |
| Flatfix Tyre Ltd | Wholesale & retail | 2026 |
| Flats 1-23 (ODD) Woodlands Road RTM Company Limited | Households | 2017 |
| Flavio Moscal Ltd | Construction | 2023 |
| Flavour Boat Limited | Extraterritorial | 2019 |
| Flavours 241 Ltd | Real estate | 2023 |
| FLD Consulting Ltd | Professional & scientific | 2018 |
| FLD Properties Limited | Real estate | 2016 |
| Fleeton Sawyer IT Ltd | Wholesale & retail | 2021 |
| Fleety Limited | Other services | 2025 |
| Flex 2 Fitness Limited | Health & social care | 2023 |
| Flight Connection Limited | Administrative & support | 2025 |
| Flight Properties Ltd | Real estate | 2021 |
| Flintstone Limited | Administrative & support | 2006 |
| Flip & Sear Events Ltd | Hospitality | 2025 |
| Flirties Limited | Wholesale & retail | 2000 |
| FLO Build&Development Ltd | Construction | 2026 |
| Floating Umbrella Ltd | Other services | 2021 |
| Flora Developments Limited | Construction | 2017 |
| Florian Joinery and Construction Ltd | Construction | 2023 |
| Florida Sun Ltd | Manufacturing | 2025 |
| Florin Ionita Ltd | Construction | 2014 |
| Florinfmgm Ltd | Construction | 2020 |
| Flourished House Ltd | Real estate | 2025 |
| Flow Plumbing & Heating Solutions Limited | Construction | 2008 |
| Flow Reformer Pilates & Wellness Ltd | Health & social care | 2025 |
| Flower POT Mews (Management) Limited | Real estate | 2010 |
| Flower Trade Consult Limited | Wholesale & retail | 2018 |
| Flowmo AI Ltd | Information & communication | 2025 |
| Flux Studios London Limited | Manufacturing | 2017 |
| FLY Project Ltd | Construction | 2024 |
| Fly-Europe Ltd | Transport & logistics | 2020 |
| Flybaku Limited | Extraterritorial | 2010 |
| Flyen Over Hills Ltd | Transport & logistics | 2024 |
| FM Nexus Enterprise Ltd | Health & social care | 2025 |
| Foam Salon Ltd | Other services | 2001 |
| Focobon Ltd | Hospitality | 2020 |
| Focused Construction & Maintenance Ltd | Construction | 2018 |
| Foley Specialist Electrical Services Limited | Construction | 2008 |
| Follow the Sun Limited | Real estate | 2020 |
| Fone Mechanics Limited | Other services | 2014 |
| Fonteyn Dancewear Limited | Wholesale & retail | 2010 |
| Foodquest Festivals Limited | Wholesale & retail | 2026 |
| Football Icon Berkshire Ltd | Arts & recreation | 2019 |
| Football Icon Buckinghamshire Ltd | Arts & recreation | 2019 |
| Football Icon Camps Limited | Education | 2023 |
| Football Icon DP Limited | Arts & recreation | 2021 |
| Football Icon Events Limited | Arts & recreation | 2016 |
| Football Icon Hertfordshire Limited | Arts & recreation | 2020 |
| Football Icon Limited | Arts & recreation | 2019 |
| Football Icon Schools Limited | Education | 2023 |
| Footy Vision Ltd | Information & communication | 2025 |
| Forage Liqueurs Limited | Wholesale & retail | 2021 |
| Force Agusta Consultancy Limited | Professional & scientific | 2019 |
| Forensic Thinking Limited | Wholesale & retail | 2019 |
| Forever Best Ltd | Wholesale & retail | 2020 |
| Forlux Ltd | Construction | 2018 |
| Form + Function Construction Ltd | Construction | 2025 |