| First Class Limited | Administrative & support | 2003 |
| First Class Property Management Limited | Construction | 2021 |
| First Class Sports Bar Limited | Hospitality | 2001 |
| First Elite Transports Ltd | Transport & logistics | 2022 |
| First Equator Investments Ltd | Real estate | 2023 |
| First Fone Ltd | Wholesale & retail | 2020 |
| First Glass Windows Limited | Construction | 2006 |
| First Homes Group Ltd | Administrative & support | 2023 |
| First Investments West Limited | Real estate | 2018 |
| First Steps AS Ltd | Health & social care | 2013 |
| First Wave Housing Limited | Real estate | 2002 |
| First Wembley Limited | Real estate | 2019 |
| First Wholesales Ltd | Wholesale & retail | 2018 |
| Firstarc Ltd | Information & communication | 2025 |
| Firstblood Entertainment Limited | Arts & recreation | 2025 |
| Firstclass Identity Ltd | Professional & scientific | 2023 |
| Firstline Services Limited | Administrative & support | 2018 |
| Fish and Go Ltd | Hospitality | 2021 |
| Fish Mark Limited | Hospitality | 2024 |
| Fish Star Media Ltd | Professional & scientific | 2013 |
| Fisher White Unlimited | Extraterritorial | 2025 |
| FISHING4TOYS&SWEETS Ltd | Wholesale & retail | 2018 |
| Fisun Limited | Administrative & support | 2021 |
| FIT2SHIFT Ltd | Transport & logistics | 2025 |
| Fitkinetix Ltd | Arts & recreation | 2018 |
| Fitness Fuel Private Limited | Health & social care | 2025 |
| Fitness Gurus Limited | Arts & recreation | 2016 |
| Fitzhaji Ltd | Construction | 2016 |
| Five Invest Ltd | Professional & scientific | 2025 |
| Five Star Enterprise (UK) Limited | Information & communication | 2012 |
| Fiveways Tyres Limited | Real estate | 1978 |
| FIX Electro Ltd | Construction | 2018 |
| Fix-It Maintenance GUY Ltd | Construction | 2025 |
| Fixie Ltd | Professional & scientific | 2018 |
| Fixitco Ltd | Construction | 2013 |
| Fixity Limited | Real estate | 2020 |
| Fizza Property Investments Limited | Real estate | 2010 |
| FKM Holding Ltd | Financial services | 2026 |
| FKM Trading 1 Ltd | Health & social care | 2026 |
| Flabbergast Ltd | Wholesale & retail | 2019 |
| Flame Shawarma Ltd | Hospitality | 2022 |
| Flamma Intimate Ltd | Wholesale & retail | 2025 |
| Flash Road Ltd | Transport & logistics | 2025 |
| Flashfleet Delivery Limited | Transport & logistics | 2026 |
| Flat 11 Arundel Street Ltd | Real estate | 2025 |
| Flat 11 Stratton House Greywell Road Ltd | Real estate | 2025 |
| Flat 24 Hammond CRT Ltd | Real estate | 2025 |
| Flavored Wings Limited | Hospitality | 2025 |
| Flavour Beauty Ltd | Other services | 2022 |
| Fleet 9INE Ltd | Administrative & support | 2025 |
| Fleet Car Rental Limited | Administrative & support | 2025 |
| Fleet Trader Limited | Administrative & support | 2021 |
| Fleetway Direct Ltd | Wholesale & retail | 2025 |
| Flexibles AI Ltd | Information & communication | 2025 |
| Flexicare and Fitness Limited | Health & social care | 2012 |
| Flexstaff Ltd | Administrative & support | 2026 |
| Flextreme Ltd | Wholesale & retail | 2025 |
| Flip Cost Limited | Wholesale & retail | 2025 |
| FLO Structures Ltd | Construction | 2023 |
| Flood Call Limited | Administrative & support | 2002 |
| Flora Athens Limited | Transport & logistics | 2021 |
| Flora's Coffee Bar Ltd | Hospitality | 2025 |
| Florence Road Management Company Limited | Households | 1980 |
| Floribo Services Ltd | Construction | 2018 |
| Florie Ltd | Professional & scientific | 2018 |
| Florin Plastering Ltd | Construction | 2018 |
| Flote Card Ltd | Information & communication | 2025 |
| Flourished District Limited | Real estate | 2022 |
| Flowra Events Ltd | Other services | 2019 |
| Fluent People Ltd | Information & communication | 2018 |
| Fluffy Bakery London Limited | Wholesale & retail | 2025 |
| FLX Ltd | Professional & scientific | 2018 |
| Flybrief Limited | Education | 2026 |
| Flyoci Limited | Professional & scientific | 2025 |
| FM Construction and Development Ltd | Construction | 2025 |
| FM Muscle Ltd | Arts & recreation | 2022 |
| FM Plumbing UK Ltd | Construction | 2018 |
| FMD (1) LLP | | 2015 |
| FMV Resources Ltd | Real estate | 2008 |
| FMV Solution Ltd | Real estate | 2023 |
| FNK Shine Ltd | Wholesale & retail | 2018 |
| FNN Limited | Transport & logistics | 2018 |
| FO Guang Ltd | Hospitality | 2025 |
| Focus Financial Consultants Ltd | Professional & scientific | 2012 |
| Focus Gaming Ltd | Wholesale & retail | 2021 |
| Focus Printing Services Ltd | Professional & scientific | 2026 |
| Focus Solutions Services Ltd | Real estate | 2023 |
| Fofa Services Limited | Health & social care | 2012 |
| Fokus Sheet Metal Limited | Manufacturing | 2001 |
| Fokus Today Limited | Construction | 2023 |
| Fone Range Limited | Professional & scientific | 2000 |
| Fone US Wembley Ltd | Wholesale & retail | 2019 |
| Food and News Ltd | Wholesale & retail | 2016 |
| Food City Limited | Extraterritorial | 2019 |
| Food Hall Group Limited | Information & communication | 2017 |
| Food Hall Studios Limited | Information & communication | 2022 |
| Food IS King Limited | Manufacturing | 2021 |
| Food Lords (UK) Limited | Wholesale & retail | 2007 |
| Food Lords Ltd | Wholesale & retail | 2010 |
| Food Services (London) LLP | | 2010 |