| Fieldhouse Site Services Ltd | Construction | 2016 |
| Fieldsend Associates Limited | Professional & scientific | 2017 |
| Fiesta Plant Limited | Wholesale & retail | 2003 |
| Fiftynine Design Consultants Limited | Professional & scientific | 1996 |
| Filcom Filterservice Limited | Other services | 2020 |
| Filtapac Limited | Manufacturing | 2012 |
| FIN Next Limited | Professional & scientific | 2022 |
| Financial Services Transformation Ltd | Professional & scientific | 2024 |
| Finca Ghyll Limited | Real estate | 2017 |
| Finch Filtration Innovation Systems Ltd | Administrative & support | 2020 |
| Fine Tea Merchants Ltd | Wholesale & retail | 2016 |
| Finedale Construction Limited | Construction | 2017 |
| Fineyork Limited | Construction | 2008 |
| Finley Associates Limited | Professional & scientific | 2020 |
| Finproc Ltd | Information & communication | 2024 |
| Fire Industry Specialists Limited | Construction | 2015 |
| Fire Inspections Ltd | Public administration | 2022 |
| Fire Risk Control Limited | Professional & scientific | 2025 |
| Fire Works Design Ltd | Administrative & support | 2002 |
| Firecracker-Uk Limited | Professional & scientific | 2016 |
| Firefly Hairdressing Ltd | Other services | 2012 |
| Fireheart Mead Ltd | Manufacturing | 2026 |
| First Care Ambulance Limited | Transport & logistics | 2012 |
| First Class Executive Security Limited | Professional & scientific | 2023 |
| First Class Printers Limited | Manufacturing | 2020 |
| First Clinical Services Ltd | Health & social care | 2025 |
| First Lincoln Ltd | Administrative & support | 2013 |
| First Point Utilities Ltd | Construction | 2022 |
| Firth Construct Ltd | Other services | 2008 |
| Fischer Catering Services Limited | Hospitality | 2015 |
| Fisher & Wallis Contractors Ltd | Construction | 2018 |
| Fisher Motor Factors Holdings Limited | Financial services | 2021 |
| Fisher Social Work Consulting Ltd | Health & social care | 2012 |
| Fishers Plumbing and Heating Ltd | Construction | 2013 |
| Fiskerton Financial Ltd | Information & communication | 2026 |
| Fitzrovia Anaesthetists LLP | | 2022 |
| Five Bells (Bassingham) Limited | Hospitality | 2003 |
| Five Mile Business Park Management Company Ltd | Administrative & support | 2016 |
| Five Social Care Limited | Administrative & support | 2020 |
| Five Spires Ltd | Real estate | 2021 |
| Five Union Road Limited | Real estate | 2024 |
| FIX UP Looks Sharp Limited | Real estate | 2021 |
| Fixed Assets Ltd | Real estate | 2016 |
| Fixed Wire Testers Limited | Construction | 2022 |
| Fixfirm Limited | Wholesale & retail | 2012 |
| Fixit & Finish Lincs Ltd | Construction | 2025 |
| Fizzco Limited | Manufacturing | 2007 |
| FJ Crane Hire Limited | Administrative & support | 2020 |
| FJN Asset Ltd | Real estate | 2017 |
| FJN Holdings Ltd | Financial services | 2017 |
| FJN Management Services Ltd | Administrative & support | 2019 |
| FJR Automotive Limited | Wholesale & retail | 2023 |
| Fjsecurity Ltd | Administrative & support | 2023 |
| FK & Co Ltd | Hospitality | 2014 |
| FL@33 Limited | Arts & recreation | 2004 |
| Flabbergasted Squirrel Property Enterprise Limited | Real estate | 2019 |
| Flag Precision Ltd | Construction | 2025 |
| Flagleaf Farming Limited | Agriculture & fishing | 1963 |
| Flagstone Business Intelligence Limited | Financial services | 2026 |
| Flair Horseboxes Ltd | Manufacturing | 2012 |
| Flair Property Management Limited | Real estate | 2012 |
| Flames of Lincoln Limited | Wholesale & retail | 2006 |
| Flare Visual Limited | Professional & scientific | 2001 |
| Flashlock Limited | Professional & scientific | 1998 |
| Flavian Limited | Professional & scientific | 2023 |
| Flecky's Ltd | Construction | 2014 |
| Fleet Experts Ltd | Transport & logistics | 2025 |
| Fleetline (Despatch) Limited | Transport & logistics | 2001 |
| Fletcher Longstaff Limited | Professional & scientific | 2020 |
| Fletchers Industries Limited | Agriculture & fishing | 2021 |
| Fleur Alchemie Ltd | Manufacturing | 2019 |
| Fleur DE LYS Early Years Limited | Education | 2022 |
| Fleur Fashion Enterprises Ltd | Wholesale & retail | 2020 |
| Flex Care Injury Clinic Limited | Health & social care | 2024 |
| Flexicomms (UK) Limited | Information & communication | 2002 |
| FLF Property Services Ltd | Real estate | 2025 |
| Flight Links (Lincoln) Ltd | Transport & logistics | 2013 |
| Flintham & Scoley Limited | Agriculture & fishing | 1966 |
| Flipjack Consultancy Limited | Information & communication | 2014 |
| FLL Property Services Limited | Real estate | 2023 |
| Floorfillers Entertainment Ltd | Arts & recreation | 2023 |
| Flora Lincoln Ltd | Education | 2025 |
| Florens Collective C.I.C. | Education | 2026 |
| Florin Paint Ltd | Construction | 2025 |
| Flow Construct Studios Ltd | Information & communication | 2025 |
| Flow Sure Plumbing & Heating Limited | Construction | 2015 |
| Flowers by Design Lincoln Ltd | Wholesale & retail | 2024 |
| Flowers by Suzanne Limited | Wholesale & retail | 2015 |
| Fluck & Griffiths Ltd | Health & social care | 2015 |
| Flumpco Limited | Other services | 2026 |
| Flying Hire Limited | Administrative & support | 2001 |
| Flying Hire Property Ltd | Real estate | 2019 |
| Fobas Enterprises Limited | Professional & scientific | 2020 |
| Focus Technologies Limited | Hospitality | 2006 |
| Focusability Support & Care Services Ltd | Other services | 2012 |
| Focused Properties Limited | Real estate | 2020 |
| Folderway Limited | Real estate | 2003 |
| Foma Transport Ltd | Transport & logistics | 2016 |
| Fonedoctor Sales and Repairs Limited | Wholesale & retail | 2025 |
| Food Quality Management Global Limited | Hospitality | 2019 |