| Horst Construction Limited | Construction | 2014 |
| Hot Tomato Pizza Ltd | Hospitality | 2018 |
| Howard Way Management Company Limited | Households | 2014 |
| Howton Cropcare Limited | Administrative & support | 2014 |
| Huggsmead Limited | Hospitality | 2023 |
| Hunas Software Ltd | Information & communication | 2025 |
| Hush Hair & Beauty Limited | Other services | 2006 |
| Hydroseis Ltd | Professional & scientific | 2021 |
| Hythe Shipyard Limited | Manufacturing | 2025 |
| IAN Wills Holdings Ltd | Financial services | 2025 |
| Idass Fitness Ltd | Wholesale & retail | 2016 |
| Ideal Imports Ltd | Wholesale & retail | 2017 |
| IG Marketing and Business Development Limited | Professional & scientific | 2017 |
| Imhuk Limited | Information & communication | 2001 |
| IN a Pinch Cleaning Ltd | Administrative & support | 2025 |
| Independent News Limited | Information & communication | 2016 |
| Intelligent Support Systems Ltd | Information & communication | 2012 |
| IVY Farm Studios Ltd | Professional & scientific | 2022 |
| J & M Windpower Limited | Energy | 2012 |
| J Browning Limited | Construction | 2003 |
| J Hawkins Engineering Ltd | Professional & scientific | 2025 |
| J Holmes Assets Limited | Real estate | 2019 |
| J Pannell Engineering Ltd | Professional & scientific | 2026 |
| J Ross Properties Ltd | Construction | 2019 |
| J W FRY Holdings Ltd | Financial services | 2024 |
| JA Carpentry & Construction Ltd | Construction | 2024 |
| James Aldis Resource Management Limited | Professional & scientific | 2024 |
| James Law Construction Limited | Construction | 1999 |
| James YEO Cabinet Makers Ltd | Manufacturing | 2011 |
| Jamfirst Ltd | Administrative & support | 2025 |
| Jamie Harris Construction Ltd | Construction | 2025 |
| JH Building Ltd | Construction | 2019 |
| Jjoscar Limited | Construction | 2025 |
| JLS Advisor Ltd | Professional & scientific | 2022 |
| JMD PUB Co Limited | Hospitality | 2026 |
| John Walters Limited | Real estate | 2017 |
| JPB Electrical S.W. Limited | Construction | 2025 |
| JSK Property Limited | Real estate | 2003 |
| Jugise | Financial services | 2018 |
| Juliacondonart Ltd | Manufacturing | 2013 |
| JW Distillers Holdings Limited | Financial services | 2022 |
| K M Hoskin Limited | Administrative & support | 2007 |
| K Wallis Limited | Extraterritorial | 2008 |
| Karen Wallis Law LLP | | 2008 |
| Kareynolds Ltd. | Manufacturing | 2014 |
| Katlee Property Developments Limited | Real estate | 2024 |
| KB Barber Launceston Limited | Other services | 2023 |
| Keep Audio Co Ltd | Hospitality | 2022 |
| Keith Hopper Electrical Limited | Construction | 2005 |
| Kennards House Limited | Real estate | 2022 |
| Kennedy Accounting Limited | Professional & scientific | 2020 |
| Kennedy Living Limited | Real estate | 2022 |
| Kensey Building Services Limited | Construction | 2007 |
| Kensey Consultants Ltd | Other services | 2014 |
| Kensey Parc Management Company Limited | Households | 2005 |
| Kern & Fable Ltd | Professional & scientific | 2025 |
| Kernow Analytical Technology Limited | Professional & scientific | 1996 |
| Kernow Assets Limited | Real estate | 2003 |
| Kernow Digital Ltd | Information & communication | 2022 |
| Kernow Engineering Solutions Ltd | Construction | 2024 |
| Kernow Financial Planning Ltd | Professional & scientific | 2020 |
| Kernow Group (Southwest) Ltd | Professional & scientific | 2022 |
| Kernow Group Limited | Professional & scientific | 2019 |
| Kernow Grub Hub Ltd | Hospitality | 2023 |
| Kernow Inns Ltd | Hospitality | 2026 |
| Kernow Installations Limited | Professional & scientific | 2008 |
| Kernow Microbiology Ltd | Professional & scientific | 2018 |
| Kernow Roast Limited | Wholesale & retail | 2025 |
| Kernow Scada Ltd | Information & communication | 2017 |
| Kernow Services Ltd | Professional & scientific | 2022 |
| Kernow Sweepers Southwest Limited | Professional & scientific | 2022 |
| KEW Venna Management Limited | Households | 2025 |
| KF Boutique Ltd | Wholesale & retail | 2025 |
| Kingscott Property Co Limited | Households | 1995 |
| Kittows Limited | Real estate | 1988 |
| KIW Property Holdings Limited | Financial services | 2026 |
| KJ Frain ALL Steel Fabrications Limited | Administrative & support | 2006 |
| Konelly Properties Ltd | Real estate | 2026 |
| Krayzee Vapes Ltd | Wholesale & retail | 2025 |
| Land at Burcroft Ltd | Construction | 2025 |
| Landmark Developments (Surrey) Limited | Construction | 2005 |
| Landrends Pump House Ltd | Water & waste | 2016 |
| Language Connected Limited | Education | 2014 |
| Lanson Management Ltd | Extraterritorial | 2010 |
| Lanson Microbe Limited | Professional & scientific | 2014 |
| Lanson Place Ltd | Real estate | 2026 |
| Lanson Recycled Non-Ferrous Metals Ltd | Wholesale & retail | 2025 |
| Lanson Refill CIC | Wholesale & retail | 2026 |
| Lanvean (Bude) Management Company Limited | Households | 2022 |
| Laponica (UK) Limited | Financial services | 2019 |
| Launceston Agricultural Association Limited | Other services | 1999 |
| Launceston Association Football Club Limited | Arts & recreation | 2007 |
| Launceston Barber Ltd | Other services | 2024 |
| Launceston Barbershop Ltd | Other services | 2026 |
| Launceston C Commerce Limited | Other services | 2025 |
| Launceston Commercials Ltd | Wholesale & retail | 2017 |
| Launceston Community Hub CIC | Health & social care | 2026 |
| Launceston Community Transport Partnership | Transport & logistics | 2008 |
| Launceston Foodbank Ltd | Health & social care | 2011 |
| Launceston Golf Club (NMR) Ltd | Arts & recreation | 2025 |