| Kirmond Services Limited | Professional & scientific | 2025 |
| Kitch International Ltd | Professional & scientific | 2020 |
| KJ Ecology Ltd | Professional & scientific | 2015 |
| KJM Engineering Limited | Manufacturing | 1998 |
| KJR Digital Limited | Professional & scientific | 2006 |
| KLD Limited | Construction | 2003 |
| KMS PT Limited | Education | 2026 |
| Kppms Limited | Professional & scientific | 2009 |
| KR Ellis Ltd | Construction | 2014 |
| Kronos Computing Ltd | Information & communication | 2023 |
| KT Packaging Limited | Administrative & support | 2022 |
| Ktbd Solutions Ltd | Information & communication | 2025 |
| Kugae Limited | Education | 2014 |
| KV Investment Properties Ltd | Real estate | 2024 |
| Kwello Ltd | Professional & scientific | 2025 |
| KYK Engineering Consultants Ltd | Professional & scientific | 2017 |
| Kymata | Professional & scientific | 2024 |
| L Hildred Electrical Ltd | Construction | 2026 |
| L Oyston Electrical Services Ltd | Construction | 2021 |
| L R Agricultural Ltd | Agriculture & fishing | 2026 |
| L.A.D. Building Ltd | Administrative & support | 2017 |
| LA Creperie Cinq Maisons Ltd | Hospitality | 2017 |
| Lakeside Consultancy Services Ltd | Professional & scientific | 2024 |
| Lamberts Warehousing Limited | Transport & logistics | 2001 |
| Landsbrook Properties Ltd. | Real estate | 2016 |
| Landscape Botanica Limited | Administrative & support | 2015 |
| Langdale-Smith and Co Limited | Construction | 2015 |
| Langtonia Ltd | Professional & scientific | 2025 |
| Lapstone Management Ltd | Households | 2020 |
| Laser Projection Solutions Ltd | Information & communication | 2021 |
| Latitude International Group Ltd | Hospitality | 2017 |
| Laughing ORC Ltd | Professional & scientific | 2022 |
| Laurel Point Limited | Wholesale & retail | 2020 |
| Learning Loft UK (Market Rasen) Community Interest Company | Education | 2026 |
| LEE Pickering GAS & Heating Limited | Construction | 2010 |
| Leonard Agri Limited | Administrative & support | 2007 |
| Lets Settle Limited | Real estate | 2024 |
| Levison & Keating Services Ltd | Health & social care | 2026 |
| Lewis Werner Investment Research Limited | Real estate | 2014 |
| Leymar Engineering Limited | Wholesale & retail | 1998 |
| LGB Consulting Limited | Education | 2020 |
| LGT Properties Ltd | Construction | 2021 |
| Liam Marchant Plumbing & Heating Ltd | Construction | 2025 |
| Libertas Global Partners Limited | Real estate | 2022 |
| Liberty Green (Lincs) Limited | Wholesale & retail | 2008 |
| Limagrain UK Limited | Wholesale & retail | 1977 |
| Lime Grove MC Limited | Households | 2023 |
| Linch Building Services Ltd | Construction | 2021 |
| Lincoln Automotive Solutions Limited | Wholesale & retail | 2017 |
| Lincoln Cosmetics Limited | Wholesale & retail | 2015 |
| Lincoln Training Academy Limited | Other services | 2020 |
| Lincolnshire Balloons Limited | Professional & scientific | 2022 |
| Lincolnshire Bathrooms & Kitchens Ltd | Professional & scientific | 2017 |
| Lincolnshire Brewing Company Limited | Manufacturing | 2006 |
| Lincolnshire Hardwoods Limited | Agriculture & fishing | 2025 |
| Lincolnshire Lifts Limited | Manufacturing | 2025 |
| Lincolnshire LOG Burners Ltd | Construction | 2026 |
| Lincolnshire Pond Plants Ltd | Wholesale & retail | 2015 |
| Lincolnshire Pond Plants Management Limited | Financial services | 2021 |
| Lincolnshire Stays Ltd | Real estate | 2026 |
| Lincolnshire Towbars Ltd | Wholesale & retail | 2022 |
| Lincs Design & Management Ltd | Manufacturing | 2007 |
| Lincs Engineering Services Ltd | Manufacturing | 2023 |
| Lincs First Choice Homes Ltd | Construction | 2019 |
| Lincs Fit (Normanby) Limited | Manufacturing | 2020 |
| Lincs Heating Ltd | Construction | 2018 |
| Lincs Industrial Roofing Limited | Administrative & support | 2016 |
| Lincs J S Holdings Limited | Financial services | 2025 |
| Lincs Joinery Services Limited | Construction | 2004 |
| Lincs Premier Homes Ltd | Construction | 2014 |
| Lincs Property Lets Limited | Real estate | 2020 |
| Lincs Renewables Limited | Construction | 2022 |
| Lincs Solar Ltd | Construction | 2023 |
| Lincs Solar Solutions Ltd | Construction | 2023 |
| Lincs Window Systems Limited | Construction | 2012 |
| Lindsey Thomas Bathroom Design Limited | Construction | 2002 |
| Links Home Improvements Limited | Wholesale & retail | 2007 |
| Linksolutions HR Ltd | Administrative & support | 2020 |
| Liquid De-Icing Systems & Services Ltd | Manufacturing | 2013 |
| Little Green Dragon Motorcycles Limited | Wholesale & retail | 2016 |
| Live Electronics Group Ltd | Financial services | 2024 |
| Live Electronics Limited | Administrative & support | 2007 |
| Live-Track Limited | Manufacturing | 2018 |
| LL Surveys LLP | | 2024 |
| LLE Group Ltd | Arts & recreation | 2019 |
| LMH Enterprise Ltd | Hospitality | 2019 |
| Locks and Leather Limited | Other services | 2004 |
| Lorriman Healthcare Services Limited | Health & social care | 2022 |
| Lotus Surveyors Ltd | Professional & scientific | 2020 |
| Lounging Hound Global Limited | Wholesale & retail | 2024 |
| Louth to Mouth Ltd | Hospitality | 2022 |
| LOW Moor Farm Ltd | Hospitality | 2012 |
| Lowtops Limited | Manufacturing | 2022 |
| LP Creatives Ltd | Arts & recreation | 2011 |
| LTW Farms Ltd | Agriculture & fishing | 2014 |
| Lucas Machinery Limited | Wholesale & retail | 2009 |
| Lucavet Ltd | Professional & scientific | 2020 |
| Lucky Island Ltd | Hospitality | 2025 |
| Lugh Consultancy Limited | Information & communication | 2020 |
| Lunar LRL Network Limited | Information & communication | 2023 |