| Kernow Business and Clinical Services Ltd | Administrative & support | 2025 |
| Kernow Cable Connections Ltd | Construction | 2021 |
| Kernow Estates Limited | Extraterritorial | 1988 |
| Kernow Plant Services Limited | Wholesale & retail | 2012 |
| Kernow Special Memories Ltd | Other services | 2018 |
| Key Solar Ltd | Construction | 2023 |
| KG Plumbing & Heating SW Ltd | Construction | 2025 |
| Khmc Limited | Financial services | 2020 |
| Killigorrick Management Company Limited | Households | 2021 |
| Kitchenside Ltd | Manufacturing | 2016 |
| Kixx Cornwall Ltd | Education | 2019 |
| Kixx Cornwall West Ltd | Education | 2021 |
| Knight Electrical (SW) Ltd | Construction | 2021 |
| Knight Properties (Nationwide) Ltd | Manufacturing | 2022 |
| Knowle Accountancy Ltd | Professional & scientific | 2017 |
| Knowle Farm Partnership | | 1994 |
| KV Accounting Solutions Limited | Professional & scientific | 2015 |
| Kwong LEE 1 Limited | Hospitality | 2023 |
| Kwrsp Limited | Wholesale & retail | 2025 |
| L H Bridge Ltd | Construction | 1995 |
| L&H Green Ltd | Real estate | 2024 |
| LA Accountancy Services Limited | Professional & scientific | 2015 |
| Ladye Park Developments Limited | Construction | 2024 |
| LAL Askar Consulting Ltd | Professional & scientific | 2023 |
| Lambert Construction Services Ltd | Professional & scientific | 2014 |
| Lamellion Holdings Ltd | Real estate | 2021 |
| Lamorna Park Management (NO 1) Limited | Households | 1989 |
| Lamorna Park Management (NO.2) Limited | Households | 1990 |
| Lamorna Park Management (NO.3) Ltd | Households | 1994 |
| Land and Heritage Ltd. | Agriculture & fishing | 2017 |
| Lantoom Meadows Apartments Management Company Limited | Households | 2016 |
| Larch Management Company Limited | Households | 1988 |
| Lark Rise Consulting Ltd | Professional & scientific | 2026 |
| Lark Solutions Cornwall Ltd | Transport & logistics | 2021 |
| Launceston Motor Cycle Club, Limited | Arts & recreation | 2004 |
| Laws Meat, Game and Fish Limited | Wholesale & retail | 2023 |
| Lesta’S Home Selects Ltd | Wholesale & retail | 2024 |
| Lesu Ltd | Arts & recreation | 2015 |
| Lewis GAS Services Limited | Construction | 2008 |
| Lewis Technical Ltd | Professional & scientific | 2023 |
| Licoholdings Limited | Information & communication | 2025 |
| Lifetime Strategy Limited | Professional & scientific | 2021 |
| Lighthouse Community Centre C.I.C. | Health & social care | 2018 |
| Lime Tree Financial Planning Ltd | Financial services | 2013 |
| Liskeard and Looe RFC Ltd | Other services | 2010 |
| Liskeard Car Sales Ltd | Wholesale & retail | 2023 |
| Liskeard Car Wash Ltd | Administrative & support | 2023 |
| Liskeard Carpets & Flooring Ltd | Wholesale & retail | 2015 |
| Liskeard Enterprises Limited | Construction | 2017 |
| Liskeard Leisure Limited | Arts & recreation | 2006 |
| Liskeard Nails and Spa Ltd | Other services | 2025 |
| Liskeard Property Management Ltd | Financial services | 2021 |
| Liskeard Radio Limited | Information & communication | 2016 |
| Liskeard Super Hand Car Wash Ltd | Other services | 2026 |
| Liskerret Woods Management Company Limited | Households | 2007 |
| Liskerrett Cleaning Services Ltd | Administrative & support | 2023 |
| Liskerrett Lettings Ltd | Real estate | 2023 |
| Little Jems Limited | Wholesale & retail | 2012 |
| Little Rising Stars Childcare Limited | Health & social care | 2012 |
| Little Upton Court Management Co Limited | Households | 2019 |
| Live Your Style Limited | Wholesale & retail | 2014 |
| LJ FOX Ltd | Professional & scientific | 2024 |
| Llawnroc Ventures Ltd | Households | 2016 |
| Lloyds Residential Limited | Real estate | 1999 |
| Lockington Limited | Construction | 2002 |
| Looe Boats Ltd | Wholesale & retail | 2012 |
| Looe Property Ltd | Construction | 2025 |
| Lovely Flowers Ltd | Wholesale & retail | 2016 |
| Loveny Holdings Ltd | Agriculture & fishing | 2016 |
| Lowarth Grove (Trematon) Management Company Ltd | Households | 2025 |
| Lower Penhale Management Company Limited | Households | 2024 |
| LSJ Construction (South West) Ltd | Construction | 2020 |
| Luqiours Fruits DE MER Limited | Hospitality | 2019 |
| LVE Music Ltd | Arts & recreation | 2024 |
| Lynher Construction Ltd | Construction | 2005 |
| M & M Construction (South West) Limited | Construction | 2006 |
| M & M Contractors Limited | Construction | 2008 |
| M & P Electrical (Cornwall) Ltd | Construction | 2010 |
| M C Bettison Groundworks Limited | Construction | 2005 |
| M Connell Fencing Limited | Construction | 2018 |
| M K Andrew Building Ltd | Construction | 2016 |
| M Perry Associates Ltd | Professional & scientific | 2017 |
| M. Scoble Construction Limited | Construction | 1997 |
| M.S. Builders & SON Ltd | Construction | 2018 |
| M2 Catering Ltd | Hospitality | 2022 |
| Madhawke Limited | Wholesale & retail | 2021 |
| Magnolia Court (Liskeard) Management Company Limited | Households | 2007 |
| Mansell Construction Ltd | Construction | 1998 |
| Mansell Property Holdings Ltd | Construction | 2020 |
| Mansell Tower Gateway Ltd | Construction | 2024 |
| MAP Technical Services Limited | Construction | 1995 |
| Marc Kitchen-Smith Limited | Wholesale & retail | 1998 |
| Marchington White Financial Planning Limited | Financial services | 2006 |
| Marine and Steam Ltd | Agriculture & fishing | 2007 |
| Mariosie Limited | Wholesale & retail | 2026 |
| Mariposa Ltd | Construction | 2020 |
| Market Court (Launceston) Management Company Limited | Households | 1991 |
| Mathy Properties Limited | Real estate | 2022 |
| Mayfield Animals Limited | Agriculture & fishing | 2026 |
| MC & MC Restaurants Ltd | Hospitality | 2022 |