| Laser Electronics (International) Limited | Professional & scientific | 2003 |
| Laurence Kirkby(Farms)Limited | Agriculture & fishing | 1958 |
| LBF Finance Limited | Financial services | 2024 |
| Liam’S Collectibles Ltd | Wholesale & retail | 2021 |
| Lincoln Diesels Limited | Wholesale & retail | 1997 |
| Lincoln Electrical Ltd | Construction | 2020 |
| Lincoln Laser Skincare Ltd | Health & social care | 2006 |
| Lincoln ZOO Limited | Agriculture & fishing | 2005 |
| Lincolnshire Flooring Company (1977) Limited | Wholesale & retail | 1977 |
| Lincolnshire Flooring Contracts Limited | Construction | 1989 |
| Lincolnshire Flooring Holdings Limited | Financial services | 2017 |
| Lincolnshire Herbs Ltd | Agriculture & fishing | 1997 |
| Lincolnshire Trading Co. Ltd | Wholesale & retail | 1998 |
| Linda O'Hern Limited | Administrative & support | 2005 |
| LNA Secretarial Services Limited | Extraterritorial | 1991 |
| Longmore Properties Limited | Real estate | 1999 |
| Louth & District Indoor Bowling Club Limited | Arts & recreation | 1989 |
| Louth and Grimsby Properties Ltd. | Real estate | 2007 |
| Louth Building Supplies (2002) Limited | Wholesale & retail | 2002 |
| LTP Driver Training | Education | 2016 |
| Luda Interior Architecture Limited | Manufacturing | 2000 |
| Lumitec Limited | Information & communication | 2001 |
| M and J Guest House Ltd | Hospitality | 2012 |
| M Woods Transport Limited | Transport & logistics | 2007 |
| M X Onboard Limited | Manufacturing | 2005 |
| M. Horn & Co. Ltd | Financial services | 1988 |
| M. R. J. Faulks and SON Limited | Administrative & support | 2006 |
| M.J. Worth Limited | Agriculture & fishing | 1970 |
| M2 Lincs Limited | Information & communication | 2006 |
| Maas Media Limited | Information & communication | 1997 |
| Macdonald's Engineers Limited | Agriculture & fishing | 2002 |
| Magna Carta Electrical Services Limited | Construction | 2005 |
| Main Cleaning Contractors Limited | Professional & scientific | 2001 |
| Mainstream Fisheries Limited | Agriculture & fishing | 2003 |
| Manny Bernstein (Credit Betting) Limited | Administrative & support | 1983 |
| Maples Solicitors LLP | | 2006 |
| Maples Stores PLC | Extraterritorial | 2006 |
| Marbridge (Developments) Limited | Construction | 2006 |
| Mark Jeffs Hair and Beauty Studios Limited | Other services | 2006 |
| Mark Rice Estate Agents Limited | Real estate | 2007 |
| Mark Stubbs Transport Limited | Transport & logistics | 2005 |
| Mark Watkinson Limited | Information & communication | 2003 |
| Market Rasen Racecourse Limited | Arts & recreation | 1924 |
| Marshall Street Regeneration Limited | Construction | 2005 |
| Martin Lishman Limited | Manufacturing | 1999 |
| Martin Wright Surveyors Limited | Professional & scientific | 2003 |
| Marylands Farm Limited | Agriculture & fishing | 1985 |
| Mawthorpe Farms Limited | Agriculture & fishing | 1954 |
| MCB Solutions Limited | Administrative & support | 2003 |
| Mcdermott's Academic Consultancy and Services (Macs) Limited | Professional & scientific | 2012 |
| Mcfarland Contractors Limited | Agriculture & fishing | 2007 |
| Mellor & Beer Estate Agents Limited | Real estate | 2004 |
| Mellor & Beer Property Management Limited | Real estate | 2006 |
| Melvyn Moffatt & Co. Limited | Real estate | 1961 |
| Mercury Productions Ltd | Information & communication | 2006 |
| MHJ Barbers Ltd | Other services | 2023 |
| Michael COX Accounting Services Limited | Administrative & support | 1998 |
| Michael Williams Decorators Limited | Construction | 2003 |
| Micrometric Limited | Manufacturing | 1998 |
| Micron Clean Products Limited | Wholesale & retail | 1988 |
| Micronclean Limited | Other services | 1921 |
| Micropos Limited | Information & communication | 1995 |
| Microsage Limited | Health & social care | 2005 |
| Mike Clark Limited | Real estate | 1997 |
| Mill Lodge Homes Limited | Construction | 1987 |
| Millford Property Limited | Real estate | 2012 |
| Millthorpe Properties Limited | Real estate | 2007 |
| Mistlemore Properties Limited | Real estate | 2000 |
| Mistley Quay & Forwarding Company Limited(The) | Professional & scientific | 1976 |
| Mjhs Properties Limited | Real estate | 2020 |
| MJS Retail Limited | Wholesale & retail | 2001 |
| MKS Draughting Limited | Professional & scientific | 2004 |
| MKS Limited | Real estate | 1995 |
| MM Dixon Groundworks Limited | Construction | 2005 |
| Moleman Ltd | Professional & scientific | 2005 |
| Morgan Davies Property (Commercial) Ltd | Real estate | 2003 |
| Mortonretail Ltd | Wholesale & retail | 2021 |
| Moschatel Limited | Other services | 1994 |
| Mosskillers Limited | Wholesale & retail | 2006 |
| Mountain ASH Care Group Limited | Health & social care | 1995 |
| Multibuild (Lincs) Ltd | Construction | 2005 |
| Myers Quality Bakers Limited | Manufacturing | 2004 |
| N 4 Tax Limited | Professional & scientific | 2003 |
| Nationwide Plumbing and Heating Ltd | Wholesale & retail | 2001 |
| Nelson M. Green & Sons Limited | Agriculture & fishing | 1965 |
| Network for Africa | Administrative & support | 2007 |
| Neville Fickling Fishing Tackle and Bait Supplies Limited | Wholesale & retail | 2005 |
| New Park Projects (Developments) Limited | Real estate | 2003 |
| Newland Chiropractic and Neurology Centre Limited | Health & social care | 2004 |
| Newmoore Properties Limited | Real estate | 2001 |
| Nicholls Accountancy Limited | Professional & scientific | 2007 |
| Nick Hiom Limited | Wholesale & retail | 2003 |
| Nick Wattam Plumbing Ltd | Construction | 2007 |
| Nickerson Sugar Beet Seed Limited | Wholesale & retail | 2001 |
| Nigel Morley Music Services Limited | Administrative & support | 2007 |
| Nikam & Nomis Limited | Professional & scientific | 2002 |
| NJH63 & Sons Properties (2) Ltd | Hospitality | 2025 |
| Nocodeai Limited | Information & communication | 2025 |
| Nook Furniture Company Limited | Wholesale & retail | 2004 |
| North Parade Leisure Limited | Hospitality | 2007 |