| Lumea Studios Group Limited | Other services | 2026 |
| Lusso Developments Limited | Construction | 1989 |
| Lustan Ltd | Professional & scientific | 2025 |
| LV Coates Electrical Limited | Manufacturing | 2025 |
| LZR International Ltd | Wholesale & retail | 2022 |
| M & F Cunningham Ltd | Financial services | 2018 |
| M a Carpet & Vinyl Fitting Limited | Construction | 2015 |
| M J Scaffolding (Lincoln) Limited | Construction | 2008 |
| M P Ellis Services Ltd | Professional & scientific | 2021 |
| M.A.T Developers Limited | Administrative & support | 2010 |
| M.J.O. Marketing Ltd | Professional & scientific | 2013 |
| Magna Ltd | Real estate | 2025 |
| MAID2CLEAN (Bourne) Ltd | Administrative & support | 2011 |
| MAID2CLEAN(PETERBOROUGH & Boston) Ltd | Other services | 2012 |
| Mairose Property Limited | Real estate | 2018 |
| Malahide Limited | Professional & scientific | 2006 |
| Manakamana Catering Grantham Limited | Hospitality | 2021 |
| Mannmannam Limited | Hospitality | 2022 |
| Maplethorpe Lettings Limited | Real estate | 2024 |
| Marc Van Morgan Limited | Wholesale & retail | 2005 |
| Mark Scotney Law Ltd | Professional & scientific | 2021 |
| Market Harmony Limited | Financial services | 1998 |
| Marrio Trans Ltd | Transport & logistics | 2021 |
| Masters Tuition Limited | Education | 2024 |
| Matt's Garage Ltd | Wholesale & retail | 2023 |
| Maxice Solutions Ltd | Professional & scientific | 2026 |
| Maxtron Services Limited | Other services | 2026 |
| Mayday Minds Ltd | Hospitality | 2019 |
| MB Bars and Events Ltd | Hospitality | 2020 |
| MCG (Lincs) Ltd | Wholesale & retail | 2012 |
| Mclaren Tree Services Ltd | Other services | 2019 |
| Mclean Roofing East Limited | Construction | 2022 |
| Mclean Roofing North Limited | Construction | 2022 |
| Mclean Roofing West Limited | Construction | 2022 |
| Meadowgate Property Management Limited | Households | 2022 |
| Meadwell Design and Installation Ltd | Construction | 2019 |
| MED Consultancy (UK) Limited | Administrative & support | 2010 |
| Media Seeds Ltd | Professional & scientific | 2024 |
| Meet a Mentor Limited | Education | 2019 |
| Melton Training Services Ltd | Administrative & support | 2011 |
| Mend Therapy Ltd | Arts & recreation | 2014 |
| Mercat Group Ltd | Mining & quarrying | 2026 |
| Meridian Lincs Limited | Other services | 2025 |
| Meridian Travel UK Limited | Administrative & support | 1999 |
| Messenger and Daughters Ltd | Households | 2022 |
| MF K9 Ltd | Other services | 2025 |
| MG Skip Hire & Recycling Limited | Water & waste | 2009 |
| Mi-Tec IT Solutions Ltd | Wholesale & retail | 2021 |
| MIE Projects Ltd | Manufacturing | 2021 |
| Mikay Limited | Health & social care | 2023 |
| Miles of Smiles Childminding Ltd | Education | 2023 |
| Milestone Home Improvements Ltd | Construction | 2012 |
| Minster Fine Foods Limited | Wholesale & retail | 2007 |
| Miodek Transport Ltd | Transport & logistics | 2022 |
| Mirage Architects Limited | Professional & scientific | 2026 |
| Mirror Finish Valets Limited | Other services | 2012 |
| Miss Motivator Ltd | Health & social care | 2020 |
| MJB Music Limited | Wholesale & retail | 2004 |
| MMC Offsite Homes Ltd | Construction | 2018 |
| MND Properties LLP | | 2015 |
| Mobile Masters Bourne Ltd | Wholesale & retail | 2025 |
| Modern Vintage Limited | Wholesale & retail | 2022 |
| Modus Skin LAB Ltd | Health & social care | 2026 |
| Mongkhon Limited | Hospitality | 2025 |
| Monument Joinery Limited | Manufacturing | 2017 |
| Moon Taxis Bourne Ltd | Transport & logistics | 2026 |
| Moore Unidrill Manufacturing Limited | Manufacturing | 2019 |
| More Than Just a Gift (DLH) Ltd | Wholesale & retail | 2021 |
| Morris Softeners Ltd | Water & waste | 2016 |
| Motorsport Design Ltd | Extraterritorial | 2009 |
| Motoryst Ltd | Information & communication | 2022 |
| MPM Plumbing & Heating Ltd | Construction | 2019 |
| MSL Productions Ltd | Arts & recreation | 2025 |
| MSN Infosolutions Limited | Information & communication | 2014 |
| Multicylinder Ltd | Wholesale & retail | 2022 |
| Mureli & Co Service Ltd | Construction | 2025 |
| MW Law Limited | Financial services | 2015 |
| My Accountancy Limited | Professional & scientific | 2018 |
| My.Lab Hair & Beauty Ltd | Other services | 2020 |
| My.Lab Hair & Beauty Stamford Ltd | Other services | 2022 |
| My.Lab Rentals Ltd | Real estate | 2025 |
| N H Dawes Limited | Financial services | 2015 |
| N.J. Pacey Landscaping Ltd | Administrative & support | 1999 |
| Namron's Family Ltd | Health & social care | 2010 |
| Nanna’S Flavours Ltd | Manufacturing | 2026 |
| Nashforce Limited | Transport & logistics | 1995 |
| Nationwide Solar Limited | Construction | 2023 |
| NB Business Growth Associates Ltd | Administrative & support | 2018 |
| NCW Plant Hire Limited | Administrative & support | 2018 |
| NE Roots Limited | Professional & scientific | 2025 |
| Nelson M. Green & Sons (Morton) Limited | Wholesale & retail | 1983 |
| Newbury Industrial Services Limited | Manufacturing | 2026 |
| Newton Fallowell (Bourne Sales & Lettings) Ltd | Real estate | 2012 |
| Newton Wine Bar and Tapas Ltd | Hospitality | 2017 |
| Nico 74 Ltd | Transport & logistics | 2014 |
| Nightwear Ltd | Wholesale & retail | 2000 |
| Nira Motors Company Ltd | Wholesale & retail | 2026 |
| NMG (UK) Limited | Administrative & support | 2002 |
| NMP Medical Ltd | Health & social care | 2021 |
| NO.9 the Lake House Ltd | Hospitality | 2025 |