| FA 70OS Limited | Real estate | 2021 |
| FAB Studios (Chiswick) Limited | Administrative & support | 2015 |
| Fabian Hirose Management Consulting Limited | Professional & scientific | 2021 |
| Face Clinic Ltd | Health & social care | 2001 |
| Facestudiod Ltd | Health & social care | 2021 |
| Factform Limited | Administrative & support | 2019 |
| Factform Solutions Limited | Administrative & support | 1995 |
| Factotum Creative Services Limited | Professional & scientific | 2020 |
| Factotum Holdings Limited | Financial services | 2025 |
| Factotum Travel Services Limited | Administrative & support | 2020 |
| Factotum UK Holdings Limited | Financial services | 2020 |
| Fadders Consultancy Ltd | Financial services | 2014 |
| Fadders Global Ltd | Financial services | 2018 |
| Fade & Co Borehamwood Limited | Other services | 2024 |
| Fadius Landscaping Ltd | Administrative & support | 2022 |
| Fair Finance Limited | Financial services | 1995 |
| Fair Weather London Ltd | Wholesale & retail | 2026 |
| Fairacre Court (1998) Limited | Households | 1998 |
| Fairacre Court Residents Association (Northwood) Limited | Households | 1965 |
| Fairtrade Vehicle Sales Limited | Administrative & support | 2016 |
| Fairway Family Investment Company Limited | Financial services | 2019 |
| Faisca Ltd | Transport & logistics | 2024 |
| Faith Works Ltd | Health & social care | 2017 |
| Faithful Ventures Ltd | Information & communication | 2026 |
| Falco Film Services Ltd | Arts & recreation | 2024 |
| Falcon Feature Services Ltd | Information & communication | 2025 |
| Falcon Medical Services Ltd | Information & communication | 2016 |
| FALCON25 Limited | Financial services | 2025 |
| Falcondale Country House Estate Ltd | Hospitality | 2000 |
| Falconwood Estates Ltd | Real estate | 2004 |
| Falp Investments Ltd | Real estate | 2023 |
| Famagusta Investments LLP | | 2020 |
| Family First Healthcare Ltd | Health & social care | 2016 |
| Family Greek Bakery Ltd | Manufacturing | 2024 |
| Family of Hounds Limited | Manufacturing | 2016 |
| Fannia Hopkins Regulatory Consultancy Limited | Other services | 2010 |
| Fantastic Realism Productions Limited | Information & communication | 2024 |
| Fanzwall Limited | Other services | 2020 |
| FAP Holdings Ltd | Real estate | 2024 |
| Fara Investment Tech Limited | Other services | 2013 |
| Fargan Dent Limited | Health & social care | 2014 |
| Farla Care Home Supplies Ltd | Wholesale & retail | 2026 |
| Farla E-Commerce Supplies Ltd | Wholesale & retail | 2026 |
| Farla Healthcare Group Ltd | Financial services | 2026 |
| Farla Medical E-Commerce Limited | Wholesale & retail | 2023 |
| Farla Medical Healthcare Ltd | Wholesale & retail | 2022 |
| Farla Medical Supplies Ltd | Wholesale & retail | 2026 |
| Farm GAS Power Limited | Construction | 2012 |
| Farmbite Kitchen Limited | Hospitality | 2025 |
| Farmhouse Pizza (Borehamwood) Ltd | Hospitality | 2019 |
| Farmhousepizza(Sohrab) Ltd | Hospitality | 2023 |
| Farming Experts Network Limited | Agriculture & fishing | 2025 |
| FAS 1 MIP LLP | | 2021 |
| FAS 2 MIP LLP | | 2024 |
| FAS Interiors Ltd | Construction | 2025 |
| Fashion Flow Ltd | Wholesale & retail | 2025 |
| Fast & Casual Foods Ltd | Hospitality | 2024 |
| Fast 2 Finish Limited | Administrative & support | 2004 |
| Fast Contracts Limited | Construction | 2014 |
| Fast FRY Wheatleyhill Ltd | Hospitality | 2022 |
| Fast Liquidation Limited | Financial services | 2022 |
| Fast Track Civil Engineering Ltd | Construction | 2014 |
| Faster Flux Ltd | Construction | 2026 |
| Fasttrack Pumps Limited | Wholesale & retail | 2025 |
| Fatos Ltd | Construction | 2015 |
| Favour Catering & Events Ltd | Hospitality | 2010 |
| Favoured London Limited | Wholesale & retail | 2025 |
| Fazel & Co Ltd | Professional & scientific | 2012 |
| FB 70OS Limited | Real estate | 2021 |
| FB Specialist Orthopaedics Ltd | Health & social care | 2026 |
| Fbse Finance Limited | Financial services | 2009 |
| FC 70OS Limited | Real estate | 2021 |
| Fcsclothing Ltd | Wholesale & retail | 2023 |
| FD 70OS Limited | Real estate | 2021 |
| FDA Consultancy Ltd | Education | 2023 |
| FDB Constructions Ltd | Construction | 2025 |
| FDN Group Limited | Administrative & support | 2008 |
| Feastham Pizza Wirral Ltd | Hospitality | 2021 |
| Featherlands Domiciliary Care at Home Ltd | Health & social care | 2024 |
| Featherstone Partnership Limited | Administrative & support | 2020 |
| Felcroft Limited | Other services | 2019 |
| Felix Beard Ltd | Information & communication | 2020 |
| Fenchurch & West Ltd | Professional & scientific | 2019 |
| Fennorr Ltd | Wholesale & retail | 2020 |
| Fenryx Tech Ltd | Information & communication | 2025 |
| Fens Property Solutions Ltd | Construction | 2016 |
| Fenture Ltd | Manufacturing | 2018 |
| Ferengi Latinum Limited | Professional & scientific | 2015 |
| Fern and Mattock Ltd | Administrative & support | 2022 |
| Fernandez Media Ltd | Manufacturing | 2025 |
| Fernex Limited | Real estate | 1995 |
| Fernsilk Ltd | Professional & scientific | 2026 |
| Ferrier Services Limited | Construction | 2016 |
| Festival Film and Television Limited | Arts & recreation | 1992 |
| FFF Moise & Wayne Limited | Arts & recreation | 2025 |
| FFV UK Limited | Professional & scientific | 2009 |
| FGP Medical Ltd | Information & communication | 2024 |
| Fhfo Investments Limited | Financial services | 2024 |
| FHM Productions Ltd | Information & communication | 2019 |
| FHS Investments Limited | Real estate | 2022 |