| Fisearch Limited | Administrative & support | 2022 |
| Fisermed Ltd | Health & social care | 2021 |
| Fish My Chips Ltd | Hospitality | 2019 |
| Fittr Nutrition Ltd | Wholesale & retail | 2025 |
| Fitzhardinge House Management Limited | Households | 1988 |
| Fitzneal Gray Limited | Information & communication | 2019 |
| Fiuggi Restaurants Limited | Hospitality | 1987 |
| Five Horizons Wealth Management Limited | Professional & scientific | 2023 |
| Five Seasons Gardening Limited | Arts & recreation | 2016 |
| FIX I.T (Tech) Ltd | Information & communication | 2024 |
| Fixam Limited | Information & communication | 2024 |
| Fixlayer Ltd | Information & communication | 2025 |
| FIZ Catering Ltd | Hospitality | 2022 |
| Fjord International Offshore and Towing Company Limited | Mining & quarrying | 2017 |
| Flaher Logistics Limited | Information & communication | 2018 |
| Flamin' Jerk Ltd | Hospitality | 2023 |
| Flanagan Building Services Limited | Construction | 2020 |
| Flash Security Limited | Administrative & support | 2012 |
| Flavour Enroute Ltd | Information & communication | 2024 |
| Flavour Wagon Limited | Hospitality | 2024 |
| Flavours Ltd | Hospitality | 2026 |
| Flawless Plates Ltd | Administrative & support | 2022 |
| Flet UK Ltd | Wholesale & retail | 2024 |
| Flexiro Ltd | Administrative & support | 2025 |
| Flexivolt Ltd | Professional & scientific | 2024 |
| Flightpath Watch Ltd | Other services | 2018 |
| Flintstream Residents Association Limited | Households | 1983 |
| FLO DOT FLO Ltd | Professional & scientific | 2024 |
| Floored London Ltd | Construction | 2024 |
| Flooring Distributors Limited | Extraterritorial | 1965 |
| Flooring Supplies Limited | Professional & scientific | 2001 |
| Floralena's Ltd | Extraterritorial | 2025 |
| Florence Elizabeth Limited | Information & communication | 2023 |
| Florin Herman Ltd | Construction | 2017 |
| Flotab Consultants Limited | Professional & scientific | 2024 |
| Flotek Industries Holdings Limited | Wholesale & retail | 2014 |
| Flotek Industries UK Limited | Wholesale & retail | 2014 |
| Flourishing Solutions Limited | Education | 2019 |
| Flow Plates Ltd | Manufacturing | 2017 |
| Flowrite Plumbing Services Limited | Administrative & support | 2006 |
| FLR Mechanical Ltd | Construction | 2019 |
| Fluido Ltd | Information & communication | 2025 |
| Fluorescent PR Limited | Professional & scientific | 2005 |
| Flush Hygiene Limited | Administrative & support | 2010 |
| Flying Elephant Ltd | Wholesale & retail | 2021 |
| FM Laskaratos Limited | Education | 2016 |
| Fm&Bm Ltd | Transport & logistics | 2025 |
| FMC Business Affairs Limited | Administrative & support | 2015 |
| Fmta Tax Ltd | Administrative & support | 2023 |
| Focaccia Addict Limited | Hospitality | 2025 |
| Focus Plant Ltd | Administrative & support | 2019 |
| Focus Plus Consulting Limited | Administrative & support | 2010 |
| Focused Mentoring Ltd | Education | 2021 |
| Fone Smiths Ltd | Wholesale & retail | 2022 |
| Fonon E-Commerce Ltd | Wholesale & retail | 2025 |
| Food Extruder Spares Limited | Wholesale & retail | 2006 |
| Food Indian 795 Ltd | Hospitality | 2026 |
| Footprintlime Ltd | Professional & scientific | 2021 |
| FOR the Fans Online Ltd | Wholesale & retail | 2025 |
| FOR the Love of JO Limited | Financial services | 2017 |
| Forcella Pizza Limited | Hospitality | 2018 |
| Ford Maintenance Ltd | Administrative & support | 2024 |
| Fordcroft Building Services Ltd | Construction | 2017 |
| Fordmill Developments Limited | Households | 2009 |
| Fords Consulting Ltd | Wholesale & retail | 2015 |
| Foreign Language Services Holdings Limited | Financial services | 2019 |
| Forest Croft Limited | Real estate | 1988 |
| Forest Croft Management Limited | Households | 1988 |
| Forest Lawns Management Limited | Households | 1971 |
| Forestdent Limited | Health & social care | 2011 |
| Forms for ALL Ltd | Administrative & support | 2026 |
| Forstmann Schreiber Limited | Professional & scientific | 2023 |
| Fortitek Alarms Ltd | Construction | 2025 |
| Fortitude Fitness Ltd | Arts & recreation | 2022 |
| Fortress Advisory Services Limited | Administrative & support | 2016 |
| Fortress Medics Limited | Health & social care | 2010 |
| Fortuna Publishing Ltd | Information & communication | 2009 |
| Fortunate Wholesale Ltd | Wholesale & retail | 2025 |
| Fortune CP Limited | Wholesale & retail | 2004 |
| Fortune West CE Limited | Information & communication | 2015 |
| Forty Nine Albemarle Road (Grifin Court) RTM Company Ltd | Households | 2025 |
| Forty Two Solutions Ltd | Information & communication | 2024 |
| Forward Psychology Ltd | Education | 2024 |
| Forwie Solutions Ltd | Transport & logistics | 2017 |
| Forza Sound Ltd | Information & communication | 2025 |
| Four Seasons Events Ltd | Hospitality | 2020 |
| Four Seasons Minibus Company Limited | Transport & logistics | 2006 |
| FOURTEEN44 Limited | Wholesale & retail | 2022 |
| Fourth Dimension Audio Visual Limited | Administrative & support | 1999 |
| Fourth Little PIG Ltd | Construction | 2025 |
| FOX Developments Limited | Real estate | 1963 |
| Foxleas Court RTM Company Ltd | Households | 2022 |
| Foxolutions Ltd | Wholesale & retail | 2022 |
| FR Holdings London Limited | Arts & recreation | 2025 |
| Frabot Limited | Wholesale & retail | 2026 |
| Frangipani Pictures Limited | Information & communication | 2020 |
| Frankie Computer Repairs Limited | Information & communication | 2015 |
| Franx Stone Works & Restoration Ltd | Construction | 2013 |
| Frawley Construction Services Ltd | Professional & scientific | 2016 |
| Freelands Property Holdings Limited | Financial services | 2020 |