| FNF Invest Limited | Financial services | 2023 |
| FOA Limited | Manufacturing | 2006 |
| Focal Dimensions Ltd | Professional & scientific | 2000 |
| Focus Alpha Limited | Real estate | 2016 |
| Focus Football Ltd | Education | 2023 |
| Focus Martech Ltd | Professional & scientific | 2025 |
| FOCUS4 Training Ltd | Education | 2007 |
| Focused Solutions Ltd | Professional & scientific | 2025 |
| Foko Ltd | Transport & logistics | 2025 |
| Fold Theory Ltd | Professional & scientific | 2025 |
| Folkett Consulting Ltd | Administrative & support | 2017 |
| Fong's Kitchen Limited | Hospitality | 2019 |
| Fonn Ltd | Information & communication | 2019 |
| Fontenay Limited | Construction | 2012 |
| Food by Corita Limited | Hospitality | 2025 |
| Foodfacts.Org | Information & communication | 2024 |
| Football Cricket Specialists Ltd | Arts & recreation | 2013 |
| Footi Connect Ltd | Arts & recreation | 2025 |
| FOR Every Adventure Limited | Wholesale & retail | 2021 |
| Forage Technology Limited | Agriculture & fishing | 1996 |
| Foran Healthcare | Wholesale & retail | 2007 |
| Ford Signs Limited | Administrative & support | 2002 |
| Forest Road (Hugglescote) Management Company Limited | Households | 2013 |
| Forest Rock Ltd | Information & communication | 2018 |
| Forest Rock Systems Ltd | Information & communication | 2011 |
| Forestside Plumbing and Heating Limited | Financial services | 2010 |
| Forever Residential Ltd | Health & social care | 2026 |
| Forge Guest Rooms Ltd | Hospitality | 2023 |
| Forgotten Parks Ltd | Information & communication | 2012 |
| Forma Technologies Ltd | Information & communication | 2025 |
| Forman & Linacre Limited | Construction | 1939 |
| Forrester Construction Services Ltd | Professional & scientific | 2010 |
| Forthmeadow Limited | Health & social care | 2002 |
| Fortified Towers Limited | Real estate | 2023 |
| Fortis Funeral Plans Limited | Other services | 2019 |
| Fortitas Limited | Health & social care | 2010 |
| Fortoak Labels Limited | Manufacturing | 2018 |
| Fortoak Packaging Ltd | Administrative & support | 2019 |
| Fortresspoint Consulting Ltd | Information & communication | 2026 |
| Fosse Way Traders Limited | Wholesale & retail | 2025 |
| Foster & Company Weldtech Limited | Wholesale & retail | 1999 |
| Foster Industrial Holdings Limited | Financial services | 2023 |
| Foundations Financial Planning Ltd | Professional & scientific | 2025 |
| Four Feathers Limited | Real estate | 2025 |
| Four in One Ltd | Health & social care | 2003 |
| Foursight Publications Limited | Information & communication | 1996 |
| Fourth Leaf Consulting Limited | Professional & scientific | 2015 |
| FOX Golf Limited | Arts & recreation | 2026 |
| FOX Wood Homes Ltd | Real estate | 2005 |
| Fox-Jalland Consulting Ltd | Professional & scientific | 2026 |
| Foxy Promo Ltd | Administrative & support | 2025 |
| Fraser Medical Services Limited | Health & social care | 2013 |
| Fratia Reunion Ltd | Water & waste | 2025 |
| Fred Sherwood & Sons (Transport) Limited | Transport & logistics | 1974 |
| Frederick Hadfield Ltd | Wholesale & retail | 2025 |
| Free the Docs Ltd | Information & communication | 2025 |
| Freeater Ltd | Information & communication | 2024 |
| Freer Renovations UK Limited | Construction | 2004 |
| Freewalk Properties Ltd | Real estate | 2020 |
| Freight Site Ltd | Transport & logistics | 2023 |
| Freightlink Logistics (UK) Limited | Transport & logistics | 2003 |
| Fresa Projects Ltd | Manufacturing | 2014 |
| Fresh Pelagic Ltd | Wholesale & retail | 2014 |
| Fresh Today Ltd | Wholesale & retail | 2021 |
| Freshgleam Cleaning Services Limited | Administrative & support | 2024 |
| Freshprints (Leicester) Ltd | Manufacturing | 2024 |
| Frew Properties Ltd | Real estate | 2018 |
| Friesland Engineers Limited | Wholesale & retail | 1981 |
| Frobishers Sales and Lettings Limited | Real estate | 2021 |
| From HIM Ltd | Hospitality | 2024 |
| Front Financial Systems Limited | Professional & scientific | 2017 |
| Frontline Human Factors Ltd | Professional & scientific | 2024 |
| Frost Aviation Ltd | Wholesale & retail | 2021 |
| Fruitful Finance Ltd | Financial services | 2020 |
| FT Content Ltd | Information & communication | 2021 |
| Fuelable Ltd | Wholesale & retail | 2023 |
| Full Stop Training Ltd | Education | 2020 |
| Fully Distributed Systems Ltd | Manufacturing | 1999 |
| FUN Little Foodies Loughborough Ltd | Education | 2026 |
| Funding 4 Lending Limited | Financial services | 2017 |
| Funfairhires Ltd | Arts & recreation | 2015 |
| Funky Fizz Events Limited | Arts & recreation | 2024 |
| Furrows Horticulture Limited | Administrative & support | 2018 |
| Fuse 4 Performance Ltd | Manufacturing | 2024 |
| Fusion Apparels Limited | Wholesale & retail | 2018 |
| Fusion Fest Ltd | Transport & logistics | 2025 |
| Fusion UK | Other services | 1998 |
| Future Building Enterprises Ltd | Construction | 2024 |
| Future Focus Coaching & Development Ltd | Administrative & support | 2016 |
| Future Mining Components Ltd | Wholesale & retail | 2025 |
| Future Powertrain Ltd | Administrative & support | 2016 |
| Futurerate Limited | Agriculture & fishing | 1995 |
| Fydella 5 Limited | Other services | 2006 |
| G & S Services (E.Mids) Community Interest Company | Administrative & support | 2008 |
| G and L Ducklings Limited | Financial services | 2020 |
| G C S Services (Leicester) Limited | Manufacturing | 2014 |
| G Cook Limited | Professional & scientific | 2025 |
| G F Jewellery Ltd | Wholesale & retail | 2023 |
| G P Adams Electrical Contractors Limited | Construction | 2005 |
| G R Emerson Limited | Transport & logistics | 2003 |