| Four Coffee & Lounge Ltd | Hospitality | 2024 |
| Four Plus Four World CIC | Information & communication | 2025 |
| Four Star Flooring Contracts Limited | Professional & scientific | 1987 |
| Four Wall Brothers Limited | Real estate | 2020 |
| Four Wall Construction Limited | Construction | 2021 |
| Four Wall Homes Limited | Real estate | 2017 |
| Four Wall Property Limited | Real estate | 2017 |
| Four Wall Towers Limited | Real estate | 2026 |
| Foursixeight Holdings Ltd | Professional & scientific | 2025 |
| Fourstones Accountants Ltd | Professional & scientific | 2026 |
| Fourth Generation Computer Employment Agency Limited | Administrative & support | 1981 |
| Fourth Generation Computer Group Limited | Administrative & support | 2003 |
| Fourth Generation Computer Services Limited | Information & communication | 2001 |
| Fourth Generation Computers Limited | Professional & scientific | 2005 |
| Fourtysix Ltd | Real estate | 2025 |
| Fourways Partnership Limited Liability Partnership | | 2022 |
| FOX Electric UK Limited | Wholesale & retail | 2026 |
| FOX Mihai Constructions Ltd | Construction | 2020 |
| FOX Wheels Ltd | Wholesale & retail | 2020 |
| Foxes Dale Limited | Construction | 2011 |
| Foxridge Services Limited | Real estate | 2024 |
| FP Sealants Ltd | Construction | 2018 |
| FP Work Consultants Ltd | Professional & scientific | 2015 |
| FPD Services Ltd | Construction | 2017 |
| FPJ Construction Solutions Ltd | Construction | 2022 |
| FQ Fits Ltd | Wholesale & retail | 2024 |
| Frallen Limited | Administrative & support | 2012 |
| Frame Empire Ltd | Professional & scientific | 2025 |
| Framework Healthcare Ltd | Administrative & support | 2024 |
| Franck Creative Limited | Professional & scientific | 2014 |
| Frangopulo Limited | Wholesale & retail | 2025 |
| Frank & Co Jewellery Ltd | Manufacturing | 2025 |
| Frankies Bar (Hornchurch) Limited | Hospitality | 2023 |
| Frankies Transport Ltd | Transport & logistics | 2023 |
| Frankwhyt Ltd | Construction | 2024 |
| Frase Integrated Services Ltd | Construction | 2026 |
| Fraser Jones Business Limited | Professional & scientific | 2024 |
| Fraser Products Ltd | Wholesale & retail | 2022 |
| Fratelli Valentini Ltd | Hospitality | 2025 |
| Fredo Building Ltd | Construction | 2024 |
| Free Spirit Cambs C.I.C. | Health & social care | 2021 |
| Free Trade Beers and Minerals Limited | Wholesale & retail | 1991 |
| Free Trade Beers Holding Limited | Financial services | 2023 |
| Free Wifi Ltd | Information & communication | 2024 |
| Freedom for ME Limited | Wholesale & retail | 2023 |
| Freedomcom Limited | Professional & scientific | 2025 |
| Freehold Investments (Ground Rent) Limited | Real estate | 2014 |
| Freeport Development Limited | Wholesale & retail | 2001 |
| Freight in Time Limited | Manufacturing | 2025 |
| Freight Process Solutions Limited | Administrative & support | 1999 |
| Freightcare Logistics Ltd | Transport & logistics | 2023 |
| Fremy Holding Ltd | Professional & scientific | 2026 |
| French White Property Ltd | Real estate | 2019 |
| Frescoclean Limited | Administrative & support | 2024 |
| Fresh & Easy Ltd | Wholesale & retail | 2023 |
| Fresh & Exotic Online Ltd | Wholesale & retail | 2022 |
| Fresh Authentic Limited | Manufacturing | 2023 |
| Fresh Ballerz Ltd | Manufacturing | 2025 |
| Fresh Brews Ltd | Hospitality | 2023 |
| Fresh Catering Limited | Hospitality | 2023 |
| Fresh Country Foods Limited | Wholesale & retail | 2020 |
| Fresh From Market Ltd | Wholesale & retail | 2026 |
| Fresh N Fresh Ltd | Wholesale & retail | 2024 |
| Fresh Pickss Ltd | Wholesale & retail | 2024 |
| Fresh Prawnia Limited | Hospitality | 2026 |
| Fresh Start Care Services Limited | Hospitality | 2013 |
| Fresh Start Housing Service (Romford) Ltd | Real estate | 2020 |
| Fresh Start Housing Service UK Ltd | Real estate | 2018 |
| Fresh Taza Foods Ltd | Wholesale & retail | 2025 |
| Freshix Ltd | Administrative & support | 2025 |
| Freshwell Limited | Administrative & support | 2022 |
| Fresto Ilford Ltd | Transport & logistics | 2023 |
| Freya Construction Ltd | Construction | 2018 |
| Freya Laurent Ltd | Wholesale & retail | 2025 |
| FRF London Limited | Real estate | 2017 |
| Friday QS Consultancy Ltd | Professional & scientific | 2016 |
| Friend & Farrelly Property Services Ltd | Real estate | 2010 |
| Friendly Premium Car Wash Ltd | Wholesale & retail | 2026 |
| Friends Co.Op Ltd | Wholesale & retail | 2023 |
| Friends Farm Ltd | Construction | 2024 |
| FRIENDSNCOMPANY11 Ltd | Wholesale & retail | 2025 |
| Frii-World Limited | Professional & scientific | 2009 |
| FRO Selin Limited | Administrative & support | 2026 |
| Froggy Digital Ltd | Administrative & support | 2025 |
| From ME to YOU the Art of Survival C.I.C. | Education | 2021 |
| Fronety Limited | Wholesale & retail | 2025 |
| Frontline Risk Services Limited | Professional & scientific | 2017 |
| Frontrow Exclusives Limited | Wholesale & retail | 2022 |
| Frozen H2O Ltd | Manufacturing | 2018 |
| FRT Property Services Limited | Construction | 2015 |
| FRT Retrofit UK Limited | Manufacturing | 2023 |
| Fruit of HER Hands | Other services | 2025 |
| FS Clothing Ltd. | Wholesale & retail | 2017 |
| FS Construction Services Ltd | Extraterritorial | 2015 |
| FS Fire Ltd. | Manufacturing | 2016 |
| FS Taxi Services Ltd. | Real estate | 2020 |
| FSA Properties Ltd | Real estate | 2018 |
| FSD Motors Ltd | Wholesale & retail | 2024 |
| Fsdpk Limited | Wholesale & retail | 2025 |
| Fsqm Investment Limited | Health & social care | 2023 |