| FIFTY5 Homes Limited | Real estate | 2024 |
| Fiftyseven Channels Ltd | Professional & scientific | 2026 |
| FIG and Stone Ltd | Construction | 2025 |
| Figepro Ltd | Wholesale & retail | 2025 |
| Fikesi Ltd | Wholesale & retail | 2025 |
| Fillmore Harida Ltd | Wholesale & retail | 2025 |
| Fillrex Ltd | Extraterritorial | 2026 |
| Fimpson Blameda Ltd | Wholesale & retail | 2025 |
| FIN Quant Tech Limited | Wholesale & retail | 2021 |
| Financial Cents CIC | Education | 2025 |
| Financial Valuation & Risks Limited | Professional & scientific | 2014 |
| Finasee Limited | Wholesale & retail | 2025 |
| Finbaze Limited | Information & communication | 2025 |
| Fincoro Limited | Information & communication | 2025 |
| Finddentnow Ltd | Administrative & support | 2026 |
| Finessed Your Service Ltd | Real estate | 2025 |
| Fineve Properties Ltd | Real estate | 2025 |
| Finnams Management LLP | | 2015 |
| Finnvale Limited | Wholesale & retail | 2026 |
| Finsbury Legal Appointments Limited | Professional & scientific | 2006 |
| Fiorix Ltd | Wholesale & retail | 2025 |
| Fireblade E-Commerce Ltd | Wholesale & retail | 2025 |
| Fireflight Ltd | Information & communication | 2014 |
| Firethorne Resources Ltd | Professional & scientific | 2022 |
| Fireworks Media Ltd | Arts & recreation | 2025 |
| Firmusnpvazd Co., Limited | Wholesale & retail | 2025 |
| First Choice PM Ltd | Construction | 2024 |
| First Legal Recruitment Limited | Administrative & support | 2020 |
| First Line Assessments Limited | Professional & scientific | 2026 |
| Firstclassvirtual Ltd | Professional & scientific | 2022 |
| Firstpass Driving School Ltd | Education | 2026 |
| Fish With the Moon Ltd | Information & communication | 2025 |
| Fishing Cat Ltd | Information & communication | 2022 |
| Fitflow AI Technologies Ltd | Professional & scientific | 2026 |
| Fitness Energy Transformers FET Academy Ltd | Manufacturing | 2022 |
| Fitqora Service Options Ltd | Information & communication | 2026 |
| Fits London Ltd | Wholesale & retail | 2024 |
| Fitted Apparel Limited | Wholesale & retail | 2023 |
| Fitttria Ltd | Wholesale & retail | 2025 |
| Fitzpatrick Ecommerce Ltd | Wholesale & retail | 2025 |
| Fivcery Ltd | Wholesale & retail | 2025 |
| Five Henry Risk Management Services Ltd | Financial services | 2021 |
| Five Iiiii Ltd | Wholesale & retail | 2026 |
| Fivetuyellow Ltd | Wholesale & retail | 2025 |
| FIX & Flourish Ltd | Construction | 2025 |
| Fixcruit Services Ltd | Information & communication | 2025 |
| Fixo Ltd | Administrative & support | 2006 |
| FKF CIC | Health & social care | 2025 |
| Fkstore Ltd | Other services | 2025 |
| Flaaz Ltd | Wholesale & retail | 2022 |
| Flairbox Ltd | Wholesale & retail | 2025 |
| Flamewood Ltd | Wholesale & retail | 2025 |
| Flamingo Exchange Ltd | Professional & scientific | 2025 |
| Flantastic Ltd | Information & communication | 2024 |
| Flaresense Technologies Ltd | Information & communication | 2023 |
| Flashfleet Ltd | Wholesale & retail | 2024 |
| Flashy Deco Ltd | Manufacturing | 2024 |
| FLATLINES001 Ltd | Public administration | 2022 |
| Flavics Ltd | Wholesale & retail | 2025 |
| Flavor & Flow Strategy Limited | Hospitality | 2025 |
| Flavour-It Ltd | Wholesale & retail | 2018 |
| Fleet Reliance Ltd | Professional & scientific | 2026 |
| Fleet Street Photo Archive Ltd | Professional & scientific | 2025 |
| Fleetwood Maritime Ltd | Professional & scientific | 2025 |
| Fleming Medical Solutions Ltd | Health & social care | 2025 |
| Flerwa Ltd | Health & social care | 2025 |
| Fletcher Forklift Services Limited | Manufacturing | 2007 |
| Flexfell Technology Co., Limited | Wholesale & retail | 2025 |
| Flexistays Management Ltd | Real estate | 2025 |
| Flextoboot Limited | Wholesale & retail | 2024 |
| Flight Academy (Gyrocopters) Ltd | Transport & logistics | 2004 |
| Flight Academy Ltd | Transport & logistics | 2002 |
| Flight Academy Operations Limited | Transport & logistics | 2011 |
| Flightcentar Limited | Wholesale & retail | 2025 |
| Flightics Ltd | Administrative & support | 2016 |
| Flinum Limited | Wholesale & retail | 2025 |
| Flippify Ltd | Information & communication | 2025 |
| Flipsnap TEC Ltd | Wholesale & retail | 2025 |
| Floating Light Ltd | Information & communication | 2025 |
| Flogaze Ltd | Wholesale & retail | 2026 |
| Floodbusters International Ltd | Wholesale & retail | 2022 |
| Floormidable Limited | Other services | 2014 |
| Florafortune Limited | Wholesale & retail | 2026 |
| Floraluna Ltd | Wholesale & retail | 2025 |
| Florence Jane Ltd | Wholesale & retail | 2021 |
| Florich Holding Limited | Manufacturing | 2025 |
| Florida Estate Agents Ltd | Transport & logistics | 2018 |
| Florless Skincare Limited | Wholesale & retail | 2026 |
| Flourish Administration Ltd | Administrative & support | 2024 |
| Flourishing! PS92V13 Limited | Wholesale & retail | 2022 |
| Flow Learning Limited | Education | 2026 |
| Flow Property Services Ltd | Construction | 2016 |
| Flowdog Ltd | Information & communication | 2024 |
| Flower LZ Ltd | Wholesale & retail | 2025 |
| Flowspire Union Ltd | Arts & recreation | 2025 |
| Fluffy Artisan Ltd | Wholesale & retail | 2025 |
| Fluid Pilates Bootcamp Ltd | Other services | 2017 |
| Flux Gleam Ltd | Wholesale & retail | 2025 |
| Flux Network Technology Ltd | Information & communication | 2024 |
| Fluxeon Ltd | Information & communication | 2025 |