| Fructus Artis Limited | Wholesale & retail | 2018 |
| Fruitdupa Ltd | Construction | 2025 |
| Fruitful Essence Candles Ltd | Wholesale & retail | 2024 |
| FRV Tailoring Limited | Manufacturing | 2019 |
| FRX International Ltd | Construction | 2018 |
| FRY Homes Ltd | Real estate | 2020 |
| Frzn Limited | Wholesale & retail | 2019 |
| FS Cardiff Limited | Hospitality | 2024 |
| FS Communication Ltd | Administrative & support | 2018 |
| FS Health Ltd | Education | 2026 |
| Fs(Marylebone) Ltd | Wholesale & retail | 1995 |
| FS1CATERING Limited | Construction | 2018 |
| FSA Consultings Ltd | Administrative & support | 2016 |
| FSB Investments Ltd | Real estate | 2018 |
| Fsbp Limited | Real estate | 2008 |
| Fscompliance Ltd | Hospitality | 2025 |
| FSE Group Ltd | Construction | 2021 |
| FSF Property Management Ltd | Households | 2023 |
| FSG Designers Ltd | Wholesale & retail | 2022 |
| Fshz Limited | Financial services | 2015 |
| Fskshop Ltd | Wholesale & retail | 2025 |
| FSR Electrical Ltd | Construction | 2016 |
| Fstdrp Ltd | Transport & logistics | 2020 |
| FT Accountants Ltd | Professional & scientific | 2024 |
| FT Developments Ltd | Other services | 2018 |
| FT Medical Solutions Limited | Professional & scientific | 2024 |
| FTA Media Ltd | Information & communication | 2021 |
| Ftai Airopco UK Ltd | Administrative & support | 2017 |
| FTB Commerce Ltd | Wholesale & retail | 2024 |
| FTD Holdings Limited | Wholesale & retail | 2024 |
| FTT Shoping Market Ltd | Wholesale & retail | 2025 |
| FTV London Ltd | Information & communication | 2011 |
| FU International Limited | Wholesale & retail | 2021 |
| Fuel Active Limited | Manufacturing | 1999 |
| Fuel Cricket Ltd | Wholesale & retail | 2021 |
| Fuelport Ltd | Water & waste | 2025 |
| Fuhui., Ltd | Wholesale & retail | 2021 |
| Fuja Synergy Group Limited | Wholesale & retail | 2024 |
| Fujian Huijing Co., Ltd | Administrative & support | 2022 |
| Fujiwawa Pet Limited | Wholesale & retail | 2025 |
| Fulcom Ltd | Professional & scientific | 2010 |
| Fulcrum Direct Limited | Professional & scientific | 2005 |
| Fulfilllane Technology Ltd | Wholesale & retail | 2026 |
| Fulfillmentsphere Ltd | Wholesale & retail | 2023 |
| Fulfilment Finance Ltd | Wholesale & retail | 2019 |
| Fulham Sports Management Ltd | Professional & scientific | 2020 |
| Fulington Plumbing Limited | Construction | 2014 |
| Fulkoli Limited | Hospitality | 2019 |
| Full Circle Mortgages Ltd | Financial services | 2017 |
| Full Crown Market Limited | Financial services | 2019 |
| Full House Finance Ltd | Financial services | 2023 |
| Full Measure Media Ltd | Information & communication | 2016 |
| Full Metal Jacket Ranges Ltd | Arts & recreation | 2018 |
| Full Moon Estates Limited | Real estate | 2023 |
| Full Moon Hospitality Limited | Hospitality | 2023 |
| Full Moon Licences Limited | Professional & scientific | 2023 |
| Full Moon Management Limited | Professional & scientific | 2023 |
| Full Moon One Ltd | Manufacturing | 2025 |
| Full Stop Accounts Limited | Professional & scientific | 2012 |
| Full Stop Rentals Limited | Real estate | 2025 |
| Full Tank Hire Limited | Administrative & support | 2025 |
| Full-Time Ltd | Arts & recreation | 2025 |
| Fullalove Clothing Limited | Manufacturing | 2019 |
| Fullback Property Solutions Ltd | Real estate | 2026 |
| Fulleryou Ltd | Wholesale & retail | 2024 |
| Fullink Tech Limited | Information & communication | 2023 |
| Fulljob Limited | Information & communication | 2022 |
| Fullspeed Limited | Hospitality | 2015 |
| Fullstopsa Ltd | Real estate | 2025 |
| Fulltechtv Ltd | Information & communication | 2015 |
| Fully Cleaning Service Ltd | Hospitality | 2019 |
| Fully Governed Music Ltd | Information & communication | 2025 |
| Fullyfuelled Limited | Information & communication | 2015 |
| Fumae Consulting Ltd | Information & communication | 2015 |
| Fumble Folks Ltd | Wholesale & retail | 2021 |
| FUN Atomic Limited | Information & communication | 2015 |
| FUN HQ Cardiff Ltd | Arts & recreation | 2022 |
| FUN Snap Ltd | Wholesale & retail | 2025 |
| Funatick Ltd | Wholesale & retail | 2023 |
| Func Main Ltd | Information & communication | 2016 |
| Funco Ltd | Wholesale & retail | 2025 |
| FUNCTION1FITNESS Ltd | Arts & recreation | 2017 |
| Functional Microstructures Limited | Professional & scientific | 2004 |
| Functional Safety Engineering Services Limited | Professional & scientific | 2014 |
| Funding Falcon Ltd. | Professional & scientific | 2006 |
| Fundraising for YOU Ltd | Professional & scientific | 2016 |
| Fungsen Ltd | Wholesale & retail | 2024 |
| Funisoft Ltd | Information & communication | 2025 |
| Funky Creations Ltd | Wholesale & retail | 2022 |
| Funky Dragon Payroll 2 Ltd | Administrative & support | 2021 |
| Funky Hostels Limited | Hospitality | 2001 |
| Funky Tastes Fusion Limited | Hospitality | 2023 |
| Funkydelics Limited | Professional & scientific | 2001 |
| Funkytown Property Limited | Real estate | 2019 |
| Funny Feet Holiday Club Limited | Other services | 2017 |
| Funny Puff Ltd | Wholesale & retail | 2025 |
| Funnyfuzzy UK Co., Ltd. | Extraterritorial | 2021 |
| Funnyye Ltd | Manufacturing | 2025 |
| Funrats Wealth Ltd | Financial services | 2020 |
| Funstation Afterschool Club Ltd | Health & social care | 2015 |