| Lincolnshire Butchery Ltd | Wholesale & retail | 2025 |
| Lincolnshire Card Show Ltd | Administrative & support | 2024 |
| Lincolnshire EPC Limited | Other services | 2025 |
| Lincolnshire Gritters Limited | Other services | 2017 |
| Lincolnshire Pork Co Ltd | Agriculture & fishing | 1947 |
| Lincolnshire Rope Access Welding Services Ltd | Professional & scientific | 2018 |
| Lincolnshire VT Specialists Ltd | Professional & scientific | 2023 |
| Lincs Electrical & Plumbing Engineers Limited | Construction | 2005 |
| Lincs Hire & Sales Ltd | Administrative & support | 2020 |
| Lincs Letting Services Ltd | Real estate | 2018 |
| Lincs. Electrical Wholesalers Limited | Wholesale & retail | 1988 |
| Lindsey Barbers Ltd | Other services | 2025 |
| Lindsey Kesteven Limited | Other services | 2023 |
| Linea Tackle UK Limited | Manufacturing | 2022 |
| Link Care Professionals Ltd | Administrative & support | 2026 |
| Links HR Limited | Professional & scientific | 2007 |
| Lisa Bond Aesthetics Ltd | Other services | 2023 |
| Little Willow Holdings Limited | Administrative & support | 2017 |
| LIV & Associates Ltd | Other services | 2025 |
| Living by the Brick Ltd | Wholesale & retail | 2024 |
| Living Connections CIC | Health & social care | 2022 |
| LJ Aero Professional Ltd | Administrative & support | 2025 |
| LJJ Consultancy Services Ltd | Professional & scientific | 2015 |
| Llrf Consulting Services Ltd | Other services | 2022 |
| LM Property Construction Ltd | Construction | 2022 |
| LMC Group Holdings Ltd | Financial services | 2025 |
| LMC Rentals Ltd | Real estate | 2025 |
| LMC Tech Ltd | Wholesale & retail | 2025 |
| LMH Holdings (Gainsborough) Ltd | Financial services | 2025 |
| Lobo Healthcare Limited | Administrative & support | 2015 |
| Local Generation Limited | Energy | 2008 |
| Local Roofline & Patio Ltd | Construction | 2020 |
| Loci Architecture & Design Ltd | Professional & scientific | 2025 |
| Logo Financials Ltd | Professional & scientific | 2024 |
| Looby Loo's Childcare Ltd | Health & social care | 2016 |
| Loom Social Ltd | Administrative & support | 2026 |
| Loopsave Limited | Financial services | 2023 |
| Louis Ludovic Limited | Wholesale & retail | 2023 |
| Louth Physio Limited | Health & social care | 2014 |
| Love for Property Limited | Real estate | 2016 |
| Love for Scunthorpe Limited | Real estate | 2022 |
| Love of Dogs Brackenmoor Limited | Other services | 2026 |
| Lovisa Life & Leisure Ltd | Administrative & support | 2024 |
| Loynes Homes Limited | Construction | 2019 |
| LSB Stunts Ltd | Arts & recreation | 2026 |
| LTH Consultancy Limited | Professional & scientific | 2024 |
| Lugarde UK Ltd | Wholesale & retail | 2024 |
| Lumens Ltd | Wholesale & retail | 2004 |
| Lumitec Consulting Limited | Information & communication | 2018 |
| Lumyra Limited | Other services | 2025 |
| Lunar Mercantile Properties Ltd | Real estate | 2020 |
| Lupostrol Limited | Wholesale & retail | 2024 |
| LUX Laser Limited | Other services | 2026 |
| Luxhealthcare Ltd | Public administration | 2023 |
| Lynbond Holdings Ltd | Administrative & support | 2017 |
| Lynbond Ltd | Administrative & support | 1997 |
| Lynx 19 Limited | Administrative & support | 2019 |
| M Andrews Consultancy Ltd | Professional & scientific | 2024 |
| M D Hoyland Limited | Construction | 2015 |
| M S Pizza Ltd | Hospitality | 2019 |
| M T a Logistics & Transport Ltd | Transport & logistics | 2025 |
| M'N'M Tiling Limited | Construction | 2008 |
| M.R.M. Thompson Limited | Transport & logistics | 2001 |
| M7 Collective Ltd | Real estate | 2026 |
| Mac's Mot's Limited | Wholesale & retail | 2009 |
| Mach Scaffolding Design Limited | Construction | 2015 |
| Maco PSP Limited | Professional & scientific | 2023 |
| Magent Consulting Limited | Professional & scientific | 2013 |
| Magic Nevin Ltd | Wholesale & retail | 2012 |
| Maintenance Maverick Ltd | Construction | 2026 |
| Majc Engineering Ltd | Other services | 2024 |
| Make Gainsborough Ltd | Real estate | 2021 |
| Mann GRP Ltd | Financial services | 2021 |
| Mann Property Holdings Ltd | Real estate | 2021 |
| Manufacturing Systems & Technologies Limited | Manufacturing | 2011 |
| Marbaum Ltd | Administrative & support | 2025 |
| Mark Goodlad Services Ltd | Professional & scientific | 2017 |
| Mark Simmonds Planning Services Limited | Professional & scientific | 2014 |
| Mark Smith Roofing Limited | Construction | 2000 |
| Mark Wood Heating Ltd | Construction | 2003 |
| Mark's Mechanical Services Ltd | Professional & scientific | 2015 |
| Market Street Renewal Limited | Construction | 2016 |
| Marshall and SON Interiors Ltd | Wholesale & retail | 2026 |
| Marshall Scaffolding Limited | Construction | 2024 |
| Martin Site Services Ltd | Construction | 2017 |
| Maspo Logistics Ltd | Wholesale & retail | 2012 |
| Masters of Muck Ltd | Administrative & support | 2017 |
| Mastersavation Ltd | Information & communication | 2026 |
| Mastic Pointing Specialists Limited | Construction | 2002 |
| Matt Johnson Building Services Limited | Construction | 2022 |
| Matt Johnson Property Services Ltd | Real estate | 2026 |
| Matt Timby Limited | Other services | 2019 |
| Mattecca Limited | Other services | 2022 |
| MAW (Newark) Limited | Extraterritorial | 2009 |
| Mayflower Specialist School Academy Trust | Education | 2015 |
| MB Technical Limited | Professional & scientific | 2006 |
| MBS Window Systems Ltd | Manufacturing | 2005 |
| Mcculloch-Green Consultancy Limited | Real estate | 1977 |
| Mcghie Group Limited | Other services | 2019 |
| Mcguigan Rail Ltd | Construction | 2023 |