| Leatherman (UK) Limited | Extraterritorial | 1993 |
| Leavesway Properties Ltd | Real estate | 2021 |
| LEC Cleaning Services Ltd | Administrative & support | 2025 |
| LEE Read Swim School UK Limited | Arts & recreation | 2022 |
| Leisure Breaks UK Property Management Ltd | Administrative & support | 2026 |
| Leisure Parks (Holdings) Limited | Financial services | 2020 |
| Leisure Parks Limited | Hospitality | 2003 |
| Leonard Tyrer & SON Limited | Construction | 2003 |
| LEVEL41 Limited | Information & communication | 2014 |
| Levens Civil Consulting Ltd | Professional & scientific | 2017 |
| Levens Village Shop Ltd | Wholesale & retail | 2015 |
| Lewthwaite Developments Limited | Construction | 2010 |
| LGD Consulting Ltd | Professional & scientific | 2024 |
| Lielle Enterprises Limited | Real estate | 2023 |
| Life Love and Laughs Ltd | Information & communication | 2018 |
| Lifeworks by Design Limited | Professional & scientific | 2022 |
| Lightwater Tarns Country Park Limited | Hospitality | 2011 |
| Limelight Internet Ltd | Information & communication | 2012 |
| Lindeth Tarn Limited | Real estate | 1992 |
| Line-Out Trading Limited | Wholesale & retail | 2004 |
| Linkan UK & Ireland Ltd | Wholesale & retail | 2018 |
| Links Architecture Ltd | Professional & scientific | 2010 |
| Little Ducklings Day Nursery (Garstang) Limited | Administrative & support | 2007 |
| Little Skittles Ltd | Health & social care | 2018 |
| LJL Properties Limited | Real estate | 2023 |
| Lloyd Music Limited | Information & communication | 1988 |
| LMS Woollard Limited | Wholesale & retail | 2022 |
| Lola Communications Limited | Administrative & support | 2010 |
| Long Valley Campers Ltd | Hospitality | 2016 |
| Long Valley Catering Limited | Hospitality | 2011 |
| Long Valley Holidays Ltd | Hospitality | 2016 |
| Long Valley Yurts Keswick Limited | Hospitality | 2011 |
| Long Valley Yurts Windermere Ltd | Hospitality | 2011 |
| Losmusone Ltd | Hospitality | 2019 |
| Lost Valley Consultancy Ltd | Real estate | 2020 |
| Loughrigg Property Developments Limited | Construction | 2024 |
| Lound Road Garage Limited | Wholesale & retail | 1999 |
| Love Life in the Lakes Limited | Real estate | 2019 |
| Love&Learn Limited | Education | 2025 |
| Lovegear Ltd | Wholesale & retail | 2025 |
| LOW Bleaze Old Hutton Management Company Limited | Households | 2002 |
| LOW Chambers Management Company Limited | Households | 2003 |
| LOW Sizergh Barn Limited | Wholesale & retail | 2009 |
| Lowther and Dawson (Kendal) Limited | Construction | 2013 |
| LPC Services Limited | Administrative & support | 2026 |
| LRC Projects (North West) Ltd | Construction | 2023 |
| LRC Projects Holdings Ltd | Financial services | 2026 |
| LSF (Holdings) Limited | Wholesale & retail | 2011 |
| LT Cumbria Ltd | Construction | 2025 |
| Lucy Moore Consulting Ltd | Professional & scientific | 2022 |
| Luna Collective Ltd | Education | 2023 |
| Lune Geographic Ltd | Information & communication | 2023 |
| Lune Valley Pheasantries Limited | Agriculture & fishing | 2005 |
| Luverly Baby Limited | Professional & scientific | 2013 |
| Lyndon's Driving School Limited | Other services | 2006 |
| Lynster Farmers' Group Limited | Agriculture & fishing | 2023 |
| Lyth & Winster Farmers' Group CIC | Other services | 2024 |
| M & C Booth Limited | Agriculture & fishing | 2006 |
| M & C Wood Limited | Professional & scientific | 2011 |
| M & J Wilson Farming Contractors Limited | Agriculture & fishing | 2002 |
| M & W Tarmacadam Contractors Limited | Construction | 2002 |
| M B Digital Limited | Manufacturing | 2010 |
| M B Moffatt Limited | Wholesale & retail | 2009 |
| M D Properties (Kendal) Ltd | Real estate | 1980 |
| M.B.Stavert Limited | Construction | 2005 |
| M.G.D. Limited | Transport & logistics | 2001 |
| M.J.Cox(Kendal) Limited | Construction | 2019 |
| M1 Electrical Contractors Limited | Manufacturing | 2022 |
| MA Money Coach Ltd | Other services | 2022 |
| MAC Tools Limited | Wholesale & retail | 2010 |
| Macbeth, Scott & Co. Limited | Financial services | 1972 |
| Mace Building Contractors Limited | Construction | 2014 |
| Mace Construction (Kendal) Limited | Construction | 1998 |
| Mackenzie Wilson Property & Developments Ltd | Hospitality | 2023 |
| Madden Associates Limited | Professional & scientific | 2015 |
| Maddock Goods Ltd | Wholesale & retail | 2025 |
| Made in Flowers Ltd | Wholesale & retail | 2015 |
| Made to Measure Ltd | Manufacturing | 2025 |
| Maia Systems Ltd. | Professional & scientific | 2020 |
| Majc Holdings Limited | Financial services | 2017 |
| Making Great Tracks Ltd | Wholesale & retail | 2017 |
| Makinson Metals Limited | Wholesale & retail | 2020 |
| Mamu Enterprises Ltd | Hospitality | 2022 |
| Manna House (Cumbria) | Health & social care | 2012 |
| Mapdec Ltd | Manufacturing | 2014 |
| Mardix Holdings Ltd | Manufacturing | 2006 |
| Mark Beresford Ltd | Information & communication | 2025 |
| Mark Mason Construction Limited | Professional & scientific | 2008 |
| Mark Metcalfe Joinery Limited | Construction | 2013 |
| Marketing-Plus (Lancaster) Ltd | Manufacturing | 2013 |
| MARRA46 Ltd | Hospitality | 2022 |
| Martindale's Yard Management Company Limited | Real estate | 2018 |
| Masala Enterprise Ltd | Hospitality | 2024 |
| Mason + Mason Consulting Ltd | Professional & scientific | 2017 |
| Master Mini Market Kendal Ltd | Wholesale & retail | 2025 |
| Mattinson Painting & Decorating Ltd | Construction | 2022 |
| Maya Maya Limited | Wholesale & retail | 2006 |
| Maybea Media Ltd | Information & communication | 2012 |
| Maybrose Limited | Construction | 2018 |
| Mayfair & Northern Limited | Real estate | 2004 |