| Lovelock & Sons Limited | Construction | 2011 |
| Lower Abbots (Buckland Brewer) Management Company Limited | Households | 2022 |
| Lower Broad Park Management Company Limited | Administrative & support | 2018 |
| Lower Metcombe Limited | Other services | 2014 |
| Lower Westaway Court Management Company Limited | Households | 2020 |
| LPC Van Conversions Ltd | Manufacturing | 2026 |
| LPD Utopia Energy Limited | Manufacturing | 2023 |
| LS Building Services (SW) Ltd | Construction | 2019 |
| LS Vantedge Apparel Limited | Wholesale & retail | 2026 |
| LT Scaffolding Solutions Ltd | Construction | 2026 |
| LTH Services Ltd | Construction | 2022 |
| Lucky Healthcare Ltd | Wholesale & retail | 2024 |
| Luip Ltd | Health & social care | 2023 |
| Lumiere and Sculpting Light Limited | Arts & recreation | 2013 |
| Lundy Fish Company Ltd | Wholesale & retail | 2025 |
| Lundy Sky Ltd | Wholesale & retail | 2025 |
| Luongo Limited | Other services | 2006 |
| Lush Food Ltd | Hospitality | 2018 |
| LUX Electrical Devon Ltd | Construction | 2023 |
| Luxxify Ltd | Wholesale & retail | 2024 |
| LW Autos Ltd | Wholesale & retail | 2022 |
| LW Rentals 2 - the Dunes (Instow) Ltd | Hospitality | 2023 |
| LW Rentals 3 - Sky Blue (Instow) Ltd | Hospitality | 2023 |
| LW Resi Rentals Limited | Real estate | 2022 |
| LW Topco Limited | Financial services | 2022 |
| Lynton and Barnstaple Railway Community Interest Company | Wholesale & retail | 1997 |
| Lynton Cottage Facility Management Ltd | Administrative & support | 2020 |
| Lynton Cottage Residents Management Company Ltd | Households | 2019 |
| Lynwood House Residents Management Limited | Households | 2017 |
| Lyon Auto Solutions Ltd | Wholesale & retail | 2026 |
| M & D Retail Limited | Hospitality | 2008 |
| M & J Irwin Limited | Construction | 2004 |
| M Ferne Electrical Limited | Construction | 2016 |
| M L Howlett Services Limited | Transport & logistics | 2021 |
| M Latham Joinery Ltd | Manufacturing | 2016 |
| M R Stowell Accountants Limited | Professional & scientific | 2003 |
| M R YEO & SON Limited | Construction | 2006 |
| M Ward Engineering Ltd | Manufacturing | 2006 |
| M&M Incorporated Ltd | Transport & logistics | 2024 |
| M&M Retail (Barnstaple) Ltd | Wholesale & retail | 2014 |
| M. and E. Alarms (Barnstaple) Limited | Construction | 1984 |
| M.J.B. Engineering Solutions Limited | Professional & scientific | 2002 |
| M.R Thorne Construction Ltd | Manufacturing | 2023 |
| M5 Hideaway Ltd | Wholesale & retail | 2018 |
| M5 Security Limited | Administrative & support | 2015 |
| Magest Limited | Administrative & support | 2004 |
| Magma Property Group Limited | Real estate | 2016 |
| Magus Construct Ltd | Construction | 2018 |
| Magus Homes Ltd | Construction | 2020 |
| Magus Properties Ltd | Real estate | 2022 |
| Maidenarch Ltd | Hospitality | 2023 |
| Maintain a Drain Limited | Administrative & support | 2010 |
| Maisey Jones Ltd | Wholesale & retail | 2024 |
| Mallett & SON, Limited | Wholesale & retail | 1911 |
| Manning Wardle & Company Limited | Manufacturing | 1997 |
| Manorville Cars Ltd | Extraterritorial | 2017 |
| Mansard Builders Ltd | Construction | 2010 |
| Manson Solutions Limited | Information & communication | 2020 |
| Maple Retreats Limited | Construction | 2022 |
| Marcel Venn Associates Limited | Professional & scientific | 2008 |
| Marine Court (Instow) Limited | Households | 1993 |
| Mariners Arms Limited | Hospitality | 2010 |
| Marinetech Services Limited | Professional & scientific | 2021 |
| Mark Davey Carpentry Limited | Construction | 2017 |
| Mark Fenton Design Services Limited | Professional & scientific | 2025 |
| Mark Swallow Photography Limited | Professional & scientific | 2017 |
| Mark YEO Designs Ltd | Information & communication | 2019 |
| Marke & Co Ltd | Professional & scientific | 2006 |
| Marke Accountants Ltd | Professional & scientific | 2012 |
| Market European Food Ltd | Wholesale & retail | 2022 |
| Market Gardens Management Company Limited | Real estate | 2023 |
| Marketing Crescendo Ltd | Professional & scientific | 2017 |
| Markit (Training) Ltd | Information & communication | 2019 |
| Marlb Threads Ltd | Wholesale & retail | 2026 |
| Marlow Paint Supplies Limited | Wholesale & retail | 2011 |
| Marshall Carpentry & Joinery Ltd | Manufacturing | 2019 |
| Martha and Hepsie Ltd | Wholesale & retail | 2011 |
| Martin Hammett Associates Limited | Financial services | 2003 |
| Martino Healthcare Limited | Health & social care | 2026 |
| Marwood Community Hall | Real estate | 2013 |
| Marwood Hill Catering Limited | Hospitality | 2006 |
| Mass Adventures Ltd | Hospitality | 2018 |
| Mass Impact Ltd. | Administrative & support | 2020 |
| Massingale & Co. Limited | Real estate | 2010 |
| Mastermind Event Ltd | Administrative & support | 2023 |
| Mathison Holdings Limited | Financial services | 2023 |
| Mathison Marine Engineering Limited | Manufacturing | 2015 |
| Matonie Hospitality Ltd | Hospitality | 2024 |
| Matthews Brothers Holdings Limited | Real estate | 2024 |
| MAY Brothers Limited | Agriculture & fishing | 1958 |
| Mazzard Construction Limited | Construction | 2017 |
| Mazzard Developments 1 Limited | Construction | 2016 |
| Mazzard Developments Limited | Construction | 2016 |
| Mazzard High Bick Limited | Construction | 2020 |
| Mazzard Homes Group Holdings Limited | Financial services | 2024 |
| Mazzard Homes Ltd | Construction | 2025 |
| Mazzard Investments Limited | Construction | 2010 |
| Mazzard Steeple Limited | Real estate | 2017 |
| MB Developments (SW) Limited | Construction | 2025 |
| MB Restaurant Group Ltd | Hospitality | 2020 |