| Jb’S Community Outreach CIC | Education | 2020 |
| JH Motorsport Ltd | Professional & scientific | 2024 |
| JMG Retail Ltd | Wholesale & retail | 2020 |
| JNR Technical Ltd | Professional & scientific | 2025 |
| John Danby Car Sales Limited | Wholesale & retail | 2010 |
| Joseph Banks Limited | Wholesale & retail | 2007 |
| JT (Lincs) Ltd | Agriculture & fishing | 2020 |
| Kennel Consultancy (Lincs) Limited | Construction | 2005 |
| Kilby Haulage Ltd | Transport & logistics | 2024 |
| Kingswood Mortgages Ltd | Financial services | 2019 |
| Kisby Consulting Limited | Professional & scientific | 2016 |
| Kitchen Solutions Lincs Limited | Construction | 2003 |
| Knowlah Limited | Education | 2024 |
| Kriele Ltd | Manufacturing | 2015 |
| KSD 74 Ltd | Transport & logistics | 2016 |
| L J Fairburn Developments Ltd | Professional & scientific | 2016 |
| L J JEM Ltd | Arts & recreation | 2019 |
| L R Electrical Limited | Construction | 2007 |
| L. Brown & SON (Wholesale Butchers) Limited | Wholesale & retail | 1992 |
| L1 Barber Shop Ltd | Other services | 2022 |
| Lakeside Developments (Lincs) Limited | Construction | 2021 |
| Lapwings Consultants Limited | Wholesale & retail | 1992 |
| Larway Consulting Ltd | Professional & scientific | 2017 |
| Laurels Group Ltd | Wholesale & retail | 2020 |
| LC Builders (Lincs) Ltd | Construction | 2026 |
| LGM Events & Medical Ltd | Health & social care | 2022 |
| Lincolnshire Integrated Voluntary Emergency Service | Health & social care | 2003 |
| Lincolnshire Nature Limited | Extraterritorial | 1999 |
| Lincolnshire North Federation of Women's Institutes | Other services | 1992 |
| Lincolnshire Property Development Ltd | Real estate | 2020 |
| Lincolnshire Trust for Nature Conservation Limited | Professional & scientific | 1968 |
| Lincolnshire Wildlife Trust | Professional & scientific | 1948 |
| Lincrafts Limited | Wholesale & retail | 2010 |
| Lincs Farm & Equine Ltd | Professional & scientific | 2024 |
| Lincs Veterinary Solutions Limited | Professional & scientific | 2009 |
| Linking UP Limited | Education | 2006 |
| Little Treasures Baby Bank CIC | Other services | 2019 |
| Lives Education Limited | Health & social care | 2022 |
| LMA Contracting Limited | Agriculture & fishing | 2024 |
| Loakes Ltd | Manufacturing | 1963 |
| Lolium Ltd | Administrative & support | 2014 |
| London Residential Architects Limited | Professional & scientific | 2016 |
| Losable Limited | Construction | 1973 |
| LSK 85 Properties Ltd | Real estate | 2017 |
| M & K Trading (Bourne) Ltd | Administrative & support | 2014 |
| M a N Automotive Ltd | Wholesale & retail | 2024 |
| M C Boam Trinity Centre Limited | Real estate | 2002 |
| M G Water Services Ltd | Professional & scientific | 2016 |
| M J Brown Builders Limited | Construction | 2003 |
| M W Herberts Limited | Construction | 2011 |
| M&S Properties and Services Ltd | Real estate | 2024 |
| Mablethorpe and District Motor Club Limited | Arts & recreation | 1978 |
| Made by Pavilion Ltd | Professional & scientific | 2015 |
| Maggy's Centre Ltd | Professional & scientific | 2024 |
| Maid to Order Cleaning Services Ltd | Administrative & support | 2020 |
| Malachite Limited | Arts & recreation | 1973 |
| Manorclose Properties Limited | Households | 1993 |
| Martello Street Freehold Limited | Households | 2011 |
| Martin Prestige Realty Ltd | Real estate | 2025 |
| Maxhugo Ltd | Construction | 2019 |
| Mclachlan Pubs Ltd | Hospitality | 2020 |
| Mcmullan Construction Services Ltd | Professional & scientific | 2008 |
| Mellor's Farmers & Butchers Limited | Agriculture & fishing | 2005 |
| Millennium Technology Partners Limited | Administrative & support | 2024 |
| Millman & Sons Limited | Professional & scientific | 2015 |
| MK Breakdown Recovery Ltd | Wholesale & retail | 2023 |
| MKH Carwash Ltd | Administrative & support | 2026 |
| ML Surveys Limited | Construction | 2025 |
| Montebello Group Holdings Limited | Financial services | 2017 |
| Montebello Horncastle Limited | Hospitality | 2021 |
| Montebello Woodhall Spa Limited | Hospitality | 2022 |
| Moorhaven (Woodhall Spa) Management Company Limited | Households | 2004 |
| Mortons Media Group Holdings Limited | Extraterritorial | 2019 |
| Mortons Media Group Ltd | Information & communication | 1998 |
| Mortons Print and Mailing Limited | Manufacturing | 2024 |
| Mortons Print Limited | Manufacturing | 1998 |
| Motorenvy Limited | Wholesale & retail | 2022 |
| MSA Direct Ltd | Wholesale & retail | 2015 |
| MSB Consultancy Services Ltd | Professional & scientific | 2024 |
| N. I. O'Kelly Limited | Real estate | 2002 |
| Nest EGG (Poultry) Ltd | Agriculture & fishing | 2017 |
| NPH HV Limited | Energy | 2024 |
| Osberton Drive Limited | Households | 2017 |
| Oxcombe Events Limited | Hospitality | 2021 |
| Oxcombe Farms Limited | Agriculture & fishing | 2009 |
| Oxcombe Woodcraft CIC | Education | 2026 |
| P & G Design (Lincs) Limited | Professional & scientific | 2017 |
| P & J Woolley Limited | Wholesale & retail | 2004 |
| P C Building & Construction Limited | Construction | 2020 |
| Page Nelson Limited | Professional & scientific | 2008 |
| Panson Consultancy Limited | Professional & scientific | 2022 |
| Paris Texas Limited | Information & communication | 1996 |
| PCR Commercial Bodyworks Limited | Wholesale & retail | 2011 |
| PCW Property Developments Limited | Construction | 2013 |
| Pepperwood Pods Ltd | Hospitality | 2023 |
| Perfect Patch Limited | Administrative & support | 2016 |
| Perkins Newsagent Ltd | Wholesale & retail | 2022 |
| Petwood Oaks Management Company Ltd | Real estate | 2018 |
| PG Compliance Ltd | Professional & scientific | 2017 |
| Phillips Animal Health Limited | Administrative & support | 1976 |