| Italizza Limited | Hospitality | 2024 |
| J & H Hewson Ltd | Real estate | 2016 |
| J a Bathrooms Limited | Construction | 2023 |
| J a Joinery Limited | Construction | 2023 |
| J and VA Dibdin Ltd | Professional & scientific | 2003 |
| J D Associates (Design Consultants) Limited | Professional & scientific | 1994 |
| J D C (Lincs) Limited | Construction | 1997 |
| J MAW & SON (Farm) Limited | Agriculture & fishing | 2022 |
| J T Argent Electrical Limited | Construction | 2016 |
| J Toyne Services Ltd | Manufacturing | 2019 |
| J.A.Godfrey & Sons,Limited | Agriculture & fishing | 1950 |
| J.H.P. Storage Limited | Transport & logistics | 1986 |
| J.W.Cousins & Sons(Farmers)Limited | Agriculture & fishing | 1965 |
| Jack Bradford Hire Ltd | Agriculture & fishing | 2022 |
| Jack Stuart Projects Limited | Professional & scientific | 2012 |
| Jackson Agri & Plant Limited | Manufacturing | 2025 |
| Jacoco Wellness Ltd | Wholesale & retail | 2018 |
| Jahnavi and Murthy Health Limited | Health & social care | 2019 |
| James Bush Cars Limited | Wholesale & retail | 2021 |
| James Smith (Scotland Nurseries) Limited | Wholesale & retail | 1986 |
| Jamesville Marina Ltd | Hospitality | 2024 |
| Jaques Developments Ltd | Real estate | 2026 |
| Javelin Trackdays Ltd | Arts & recreation | 2013 |
| Jaylaurs Ltd | Wholesale & retail | 2025 |
| Jaymek Engineering Limited | Manufacturing | 2003 |
| JCC FM Services Ltd | Professional & scientific | 2024 |
| JD Transport Solutions Ltd | Transport & logistics | 2015 |
| Jerry Green Dog Rescue | Other services | 2013 |
| JG Consultancy Limited | Professional & scientific | 2016 |
| JH Charles Ltd | Professional & scientific | 2017 |
| JID Electrical Contractors Ltd | Construction | 2018 |
| JIM 10 Pizza Ltd | Hospitality | 2026 |
| JIM Toyne Electrical Limited | Construction | 2017 |
| Jklm Farm Ltd | Agriculture & fishing | 2023 |
| JM Heavy Plant Ltd | Construction | 2022 |
| JMP Support Ltd | Education | 2012 |
| John E Winship Motor Engineers Limited | Wholesale & retail | 2002 |
| John M. Dodds Limited | Agriculture & fishing | 1975 |
| John Reid Trucking Limited | Transport & logistics | 1997 |
| John Waudby Consulting (JWC) Limited | Professional & scientific | 2026 |
| Jomo Financial Limited | Financial services | 2018 |
| JSN Blading Limited | Professional & scientific | 2017 |
| K & L Quality Care Consultancy Ltd | Professional & scientific | 2025 |
| K S B Properties Ltd | Real estate | 2011 |
| Karmony Limited | Hospitality | 2020 |
| Kbpro Medical Services Ltd | Health & social care | 2014 |
| KEF Holdings Ltd | Financial services | 2019 |
| Keles CUT Ltd | Other services | 2025 |
| Kennedi Limited | Wholesale & retail | 2012 |
| Kensmith Industries Ltd | Wholesale & retail | 2025 |
| Keson Homes Limited | Construction | 2007 |
| Kettleby Developments Ltd | Real estate | 2019 |
| Kettleby Lane West Developments Limited | Construction | 2021 |
| Kettleby Leisure Ltd | Hospitality | 2019 |
| Kettleby TF Ltd | Real estate | 2019 |
| Key Electrical Installation Services Ltd | Construction | 2023 |
| Keyo Agricultural Services Ltd | Agriculture & fishing | 1992 |
| Keyo Agriculture Limited | Extraterritorial | 2017 |
| Keyo Holdings Ltd | Professional & scientific | 2002 |
| Keyo Limited | Professional & scientific | 2005 |
| KHS (Immingham) Limited | Real estate | 2023 |
| Kieran Tulloch Ltd | Construction | 2024 |
| Kingston Equity & Finance Limited | Financial services | 1985 |
| Kirmington Farms Limited | Extraterritorial | 1976 |
| Kirmington Potato Services Limited | Wholesale & retail | 1987 |
| Kirton Concrete Services Ltd. | Construction | 2002 |
| Kitson Audio Ltd | Administrative & support | 2024 |
| KJH Plant and Commercial Services Ltd | Wholesale & retail | 2023 |
| Kneesall Shoot Limited | Agriculture & fishing | 2015 |
| Krunch Consultancy Ltd | Professional & scientific | 2025 |
| L & N Trucking Limited | Transport & logistics | 2004 |
| L & S Media Creations Ltd | Wholesale & retail | 2026 |
| L M Robinson Consulting Ltd | Information & communication | 2020 |
| L@Ncaster and Co Ltd | Real estate | 2023 |
| Ladlow Technologies Limited | Transport & logistics | 2003 |
| Lancaster & Sons Limited | Agriculture & fishing | 2014 |
| LAS Aviation Solutions Ltd | Transport & logistics | 2024 |
| Lashtan Brigg Limited | Other services | 2023 |
| Layburn Investments Ltd | Real estate | 1965 |
| LCR Agricultural Services Ltd | Manufacturing | 2023 |
| LCT Traffic Ltd | Construction | 2022 |
| Leavah Services Limited | Construction | 2015 |
| LEN Manchester (Holdings) Limited | Professional & scientific | 2002 |
| Levitt Joinery Ltd | Construction | 2003 |
| Leya Buster Interiors Ltd | Wholesale & retail | 2025 |
| LG Property Solutions Ltd | Real estate | 2025 |
| Lgbuysgroup Ltd | Extraterritorial | 2024 |
| Liddy Homes Ltd | Construction | 2021 |
| Liddy Property Rentals Ltd | Real estate | 2021 |
| Life & Soul Goals Ltd | Hospitality | 2019 |
| Light Oak Property Company Limited | Real estate | 2003 |
| Light SC Ltd | Real estate | 2018 |
| Lince Holdings Ltd | Professional & scientific | 2012 |
| Lince Properties Limited | Real estate | 2004 |
| Lincolnshire Ambulance Service Ltd | Health & social care | 2022 |
| Lincolnshire Inns Ltd | Hospitality | 2019 |
| Lincolnshire Lawncare Limited | Other services | 2010 |
| Lincolnshire Rewilding Network C.I.C. | Professional & scientific | 2025 |
| Lincs Eco Energy Ltd | Construction | 2011 |
| Lincs First AID Ltd | Other services | 2016 |