| Firstkind Woundcare Ltd | Health & social care | 2019 |
| Firstlap Limited | Construction | 1995 |
| Firstserv Limited | Information & communication | 2017 |
| Firth, Firth and Smith Limited | Health & social care | 2008 |
| Fish Engineering Limited | Manufacturing | 1998 |
| Fisher & Co. (Accountants) Limited | Professional & scientific | 2005 |
| Fisher Consultancy Limited | Administrative & support | 2013 |
| Fitness Finder Ltd | Information & communication | 2026 |
| Fitness Tricolore Limited | Arts & recreation | 2024 |
| Fitnest Ltd. | Arts & recreation | 2021 |
| Fitzgerald Control Systems Limited | Administrative & support | 2016 |
| Fitzmaurice Civil Engineering Ltd | Professional & scientific | 2019 |
| Five Principles Ltd | Professional & scientific | 2023 |
| Five Star Barber Golborne Ltd | Other services | 2025 |
| Five Star Catering Equipment Hire Limited | Administrative & support | 1998 |
| Fix-It Consulting Limited | Information & communication | 2019 |
| Fixed Price Plumbing Ltd | Construction | 2026 |
| Fixit Fred Ltd | Construction | 2013 |
| Fizz Buzz Crash Ltd | Arts & recreation | 2024 |
| Fizzgig Limited | Information & communication | 2019 |
| FJ Motors Warrington Ltd | Wholesale & retail | 2023 |
| FJM Roofing Specialist Limited | Construction | 2025 |
| FKG Consultancy Ltd | Professional & scientific | 2018 |
| FLACK2020 Ltd | Professional & scientific | 2026 |
| Flairhurst Limited | Information & communication | 1997 |
| Flam Trans Ltd | Transport & logistics | 2024 |
| Flamefast (U.K.) Limited | Manufacturing | 1996 |
| Flamefast Controls (U.K.) Limited | Manufacturing | 2022 |
| Flamefast Controls Ltd | Manufacturing | 2022 |
| Flamefast Education Limited | Extraterritorial | 2013 |
| Flamefast Fire Ltd | Extraterritorial | 2019 |
| Flamefast FM Ltd | Manufacturing | 2017 |
| Flamefast GAS Safety Ltd | Manufacturing | 2016 |
| Flamefast GAS Solutions Ltd | Extraterritorial | 2019 |
| Flamefast Ltd | Manufacturing | 2017 |
| Flamefast Technology Supplies Ltd | Manufacturing | 2020 |
| Flamingo Tree Ltd | Real estate | 2024 |
| Flannery Associates Limited | Real estate | 2016 |
| Flavell's Flavours Ltd | Hospitality | 2022 |
| Flavers Warrington Ltd | Hospitality | 2025 |
| Flavius 10 Ltd | Transport & logistics | 2025 |
| Flavors & Colors Business Ltd | Manufacturing | 2026 |
| Flavour Craver Ltd | Hospitality | 2024 |
| Flavour Makers PTY Limited | Manufacturing | 2024 |
| Flawless Hair & Beauty Bar Limited | Other services | 2017 |
| FLD Design Solutions Ltd | Administrative & support | 2023 |
| Fleet Solar Limited | Construction | 2019 |
| Fleetwood Nick’D Ltd | Arts & recreation | 2026 |
| Fleming & Co Wealth Management Ltd | Financial services | 2018 |
| Fleming Metrology Solutions Limited | Professional & scientific | 2025 |
| Fletcher Fold Developments NW Ltd | Professional & scientific | 2006 |
| Fletcher Services Limited | Construction | 2005 |
| Flex Clin SCI Limited | Information & communication | 2022 |
| Flex Data Center Solutions Foreign Holdings 1 Ltd | Financial services | 2025 |
| Flex Data Center Solutions Foreign Holdings 2 Ltd | Financial services | 2025 |
| Flex U.K. Holdings, Limited | Financial services | 2025 |
| Flex-Display UK Limited | Professional & scientific | 2003 |
| Flexible Communication Limited | Information & communication | 2016 |
| Flexible Resolution Services Limited | Professional & scientific | 2022 |
| FLEXIBLEGRIDPOWER3 Ltd | Energy | 2017 |
| Flextronics Europe Limited | Professional & scientific | 1992 |
| Flextronics Global Services (Manchester) Limited | Other services | 1986 |
| Flextronics UK Limited | Professional & scientific | 1993 |
| Flint & Flint (Cheshire) Limited | Financial services | 2019 |
| Flint Percussion Limited | Wholesale & retail | 2020 |
| Flipcomm Limited | Professional & scientific | 2017 |
| Flitwick Engineering Limited | Administrative & support | 2016 |
| Flogger & Hammer Limited | Professional & scientific | 2019 |
| Floggl Ltd | Wholesale & retail | 2015 |
| Floirendo Ltd | Wholesale & retail | 2025 |
| Floor Land Logistics Ltd | Construction | 2025 |
| Floor Land Ltd | Construction | 2023 |
| Floor Land Retail Ltd | Construction | 2025 |
| Florentin Trans Ltd | Transport & logistics | 2019 |
| Flourish and Pots Limited | Administrative & support | 2013 |
| Flourish True Self Collective CIC | Education | 2025 |
| Flow Assure Limited | Professional & scientific | 2018 |
| Flow Bathrooms and Kitchens Limited | Construction | 2016 |
| Flow Coaching Academy KR Ltd | Professional & scientific | 2024 |
| Flow Nova Studios Ltd | Arts & recreation | 2025 |
| Flow Process Design Limited | Professional & scientific | 2021 |
| Flow Submission Grappling Ltd | Arts & recreation | 2024 |
| Flowater Ltd | Professional & scientific | 2018 |
| Flox DEV UK Ltd | Information & communication | 2021 |
| Flplf Ltd | Professional & scientific | 2017 |
| Fluently Consulting Ltd | Administrative & support | 2024 |
| Fluffi Ltd | Wholesale & retail | 2018 |
| FLV Limited | Transport & logistics | 2021 |
| Flygeria Limited | Professional & scientific | 2021 |
| Flying Cloud Solutions Limited | Other services | 2019 |
| Flying Frames Limited | Administrative & support | 2025 |
| Flynn Engineering Ltd | Administrative & support | 2022 |
| FM Civils Ltd | Professional & scientific | 2024 |
| FM Growth Consultants Limited | Administrative & support | 2024 |
| FMK Solutions Limited | Professional & scientific | 2011 |
| FML Property Services Ltd | Construction | 2024 |
| Fmlee Systems Ltd | Wholesale & retail | 2023 |
| FMS Business Services Limited | Administrative & support | 2024 |
| FMW Engineering Limited | Professional & scientific | 2024 |
| FNS Consulting Limited | Administrative & support | 2025 |