| Finkol Compliance Limited | Administrative & support | 2024 |
| Finley Steel Structures Ltd | Construction | 2022 |
| Finlo Frank Ltd. | Construction | 2013 |
| Finloch Limited | Health & social care | 2021 |
| Fire Free Fire Protection Ltd | Wholesale & retail | 2008 |
| Fire Installation Specialists Ltd | Extraterritorial | 2018 |
| Firecrest Management Company Limited | Households | 1983 |
| Firefly Payroll Ltd | Information & communication | 2006 |
| Firepower Limited | Real estate | 2020 |
| Firestarter Media Limited | Professional & scientific | 2010 |
| First Business Finance (UK) Ltd | Financial services | 2008 |
| First Choice Services (UK) Ltd | Construction | 2000 |
| First Class Investments Limited | Financial services | 2005 |
| First Class Mortgage Solutions Limited | Financial services | 2005 |
| First Cosec Limited | Professional & scientific | 2022 |
| First Defence Maintenance Limited | Administrative & support | 2008 |
| First Huntbourne Management Company Limited | Households | 1964 |
| First Medical Consultancy Limited | Administrative & support | 2022 |
| First Vehicle Movements Ltd | Transport & logistics | 2025 |
| Firstaid 1ST Limited | Health & social care | 2025 |
| Firstpoint Good Construction Ltd. | Construction | 2025 |
| FIS London Ltd | Construction | 2022 |
| Fishing Ferry Ltd | Hospitality | 2012 |
| Fisk Holdings Limited | Professional & scientific | 2021 |
| Fisk Properties Limited | Real estate | 2020 |
| Fit Right Floorings Ltd | Construction | 2018 |
| Fitcar Consulting Limited | Health & social care | 2019 |
| Fitcar Property Investments Ltd | Real estate | 2021 |
| Fitter Stronger Faster Gym Limited | Arts & recreation | 2017 |
| Fitter, Stronger Limited | Arts & recreation | 2015 |
| Fitz Rigging Limited | Manufacturing | 2025 |
| Fitzpatrick Wellness Group Ltd | Health & social care | 2026 |
| Five Brothers Group Limited | Administrative & support | 2016 |
| Five Rivers Holiday Lets Limited | Real estate | 2021 |
| Five Seven Nine Management Limited | Real estate | 2018 |
| Five Sons Catering Ltd | Hospitality | 2024 |
| Fiveten Productions Limited | Information & communication | 2008 |
| Fizz Cube Ltd | Information & communication | 2014 |
| FJA Jobs Associates Ltd | Administrative & support | 2021 |
| FKA Mechanical & Electrical Ltd | Construction | 2021 |
| FL Global Holdings Limited | Wholesale & retail | 2024 |
| FL Prime Logistics Ltd | Transport & logistics | 2026 |
| Flair School of Dance Limited | Education | 2020 |
| Flame Academy Ltd | Hospitality | 2023 |
| Flameco Ltd | Administrative & support | 2024 |
| Flamethrower Limited | Information & communication | 2015 |
| Flash Bang Smoke Ltd | Manufacturing | 2024 |
| Flash Hart Studio Ltd | Other services | 2024 |
| Flash Professional Services Limited | Administrative & support | 2023 |
| Flatten Engineering Ltd | Professional & scientific | 2025 |
| Flawless Cleaning Services Ltd | Other services | 2019 |
| Fledgelings Nursery Limited | Education | 2025 |
| Fleet Commercials (Kent) Limited | Administrative & support | 2024 |
| Fleet Efficiency Limited | Administrative & support | 2005 |
| Fleet Efficiency Rental Ltd | Extraterritorial | 2009 |
| Fleetfusion.Ai Limited | Information & communication | 2026 |
| Fleetlive.Ai Ltd | Information & communication | 2025 |
| Fletcher Challenge Building UK Limited | Administrative & support | 2000 |
| Fletcher Challenge Forest Industries Limited | Administrative & support | 1989 |
| Flexicruit Limited | Administrative & support | 2023 |
| Flexintons & Co Ltd | Professional & scientific | 2021 |
| Flexintons Realty Ltd | Real estate | 2024 |
| Flextronics Holding Ltd | Manufacturing | 2025 |
| Flint Asset Management Limited | Financial services | 2022 |
| FLO and Ted's Limited | Hospitality | 2023 |
| Flolube Limited | Wholesale & retail | 2024 |
| Floor Restoration Services Ltd | Construction | 2024 |
| Floor Sanding Enterprise Ltd | Transport & logistics | 2018 |
| Flooring Central Limited | Other services | 2020 |
| Floraj Ltd | Wholesale & retail | 2026 |
| Florence's Artisan Bakery Ltd | Hospitality | 2023 |
| Florida Foods Limited | Professional & scientific | 1999 |
| Floridian Drywall Ltd | Construction | 2003 |
| Florin Court (Tanner Street) Management Limited | Households | 1999 |
| Florinsifiii Ltd | Construction | 2018 |
| Flourish Digital Limited | Information & communication | 2026 |
| Flow (Maidstone) Limited | Administrative & support | 2016 |
| Flow 4 Ltd | Other services | 2022 |
| Flow Style Ltd. | Arts & recreation | 2015 |
| Flow Tech Plumbing Limited | Extraterritorial | 2022 |
| Flutemakers Guild Limited | Other services | 2005 |
| Fluxnet Solutions Ltd | Information & communication | 2026 |
| FLY Through Films Limited | Information & communication | 2015 |
| Flying Adverts Ltd | Professional & scientific | 2014 |
| Flying Tyres Ltd | Wholesale & retail | 2018 |
| Flypak by Prundaru Limited | Transport & logistics | 2024 |
| Flyte Estates Limited | Construction | 2016 |
| Flyte Projects Limited | Construction | 2021 |
| Fmcandrew Consulting Ltd | Professional & scientific | 2010 |
| FME Biomass (East) Ltd | Agriculture & fishing | 2023 |
| FME Biomass (South) Ltd | Agriculture & fishing | 2023 |
| FME Biomass Limited | Agriculture & fishing | 2020 |
| Focis Management Limited | Professional & scientific | 2018 |
| Focus Air Conditioning and Refrigeration Limited | Construction | 2007 |
| Focus Financial Limited | Financial services | 1997 |
| Focus Installations Limited | Administrative & support | 2010 |
| Focus Payroll Limited | Extraterritorial | 2004 |
| Focused Financial Ltd | Financial services | 2014 |
| Focussed Projects Ltd | Administrative & support | 2003 |
| Foiling Collective Ltd | Wholesale & retail | 2025 |