| Hazelbank Court (Plymouth) Management Company Limited | Households | 1987 |
| HCP Auctions (South West) Ltd | Wholesale & retail | 2024 |
| HCP Auctions SW Ltd | Wholesale & retail | 2022 |
| Heating (Southwest) Limited | Manufacturing | 1978 |
| Hedgefield Ltd | Real estate | 2021 |
| Heirloom & Perennial Ltd | Wholesale & retail | 2013 |
| Heiwa & Hikari Ltd | Real estate | 2026 |
| Helen Jane Limited | Financial services | 2003 |
| Hemmick Services Limited | Administrative & support | 1999 |
| Henwood Barns Ltd | Hospitality | 2018 |
| Herbert Properties Ltd | Real estate | 2024 |
| Heronside Limited | Real estate | 1989 |
| High Moor Motors Ltd | Wholesale & retail | 2025 |
| High Point Access Ltd | Construction | 2017 |
| Hivestead Ltd | Arts & recreation | 2023 |
| HJH Publishing Limited | Wholesale & retail | 2011 |
| Hocking Property Group Ltd | Hospitality | 2025 |
| Holiday Cottages (South West) Ltd | Hospitality | 2025 |
| Home Away Property Solutions Ltd | Real estate | 2023 |
| Homeglowcleaners Ltd | Administrative & support | 2025 |
| Hot WOK Liskeard Limited | Hospitality | 2023 |
| House Clearance Plymouth (South West) Ltd | Water & waste | 2024 |
| House of Crowds Ltd | Other services | 2022 |
| HP Transport Management Ltd | Transport & logistics | 2016 |
| HW Foods Limited | Hospitality | 2022 |
| Hydra Marine and Civils Ltd | Construction | 2022 |
| I. Stanton Plant Hire Ltd | Wholesale & retail | 2007 |
| Ideal Foods Limited | Wholesale & retail | 2001 |
| Ideal Nutritional Foods Limited | Wholesale & retail | 2010 |
| Ideal Pet Foods Limited | Agriculture & fishing | 2014 |
| Ideal Seafoods Limited | Agriculture & fishing | 2016 |
| Inar T&S Ltd | Wholesale & retail | 2026 |
| Incineration South West Limited | Extraterritorial | 1981 |
| Independent Football Academy Ltd | Arts & recreation | 2013 |
| Infinity Concepts Limited | Information & communication | 2024 |
| Infinity Marine Limited | Manufacturing | 2026 |
| Ingoma Limited | Wholesale & retail | 2011 |
| INNOV8ION Property Limited | Financial services | 2025 |
| Inswy 1963 Limited | Extraterritorial | 2013 |
| International Stone Ltd | Mining & quarrying | 2001 |
| Intj Ltd | Construction | 2003 |
| Invictus Investment Holdings Limited | Financial services | 2021 |
| Invictus Turnaround Management Limited | Professional & scientific | 2006 |
| ION Pack Ltd | Manufacturing | 2023 |
| ISC Consultancy Limited | Professional & scientific | 2015 |
| Island Architects Limited | Professional & scientific | 2008 |
| J P Contractors (South West) Ltd | Construction | 2021 |
| J. H. AV Limited | Administrative & support | 2009 |
| J. Rendle Carpentry Limited | Construction | 2005 |
| J.C.G Precision Masonry Ltd | Construction | 2026 |
| J.Hartnell Construction Limited | Construction | 2024 |
| James Hawken Music Ltd | Information & communication | 2024 |
| James Wadham Consultants Limited | Professional & scientific | 2010 |
| Jana Retail Limited | Wholesale & retail | 2019 |
| Janet Christine Whitton Limited | Extraterritorial | 2025 |
| Janice Elizabeth Bell Ltd | Extraterritorial | 2025 |
| Jarvis Electrical Ltd | Construction | 2025 |
| Jason Runnalls Ltd | Manufacturing | 2014 |
| Jason Walters Ltd | Extraterritorial | 2017 |
| Javelyn Holdings Ltd | Wholesale & retail | 2025 |
| JAW Hire Ltd | Administrative & support | 2020 |
| JB Film Productions Limited | Information & communication | 2022 |
| JDT Cornwall Limited | Financial services | 2025 |
| Jellie Roar Limited | Professional & scientific | 2025 |
| Jewell Properties Ltd | Real estate | 2016 |
| JG & Sons Roofing Ltd | Construction | 2026 |
| Jguard Ltd | Manufacturing | 2024 |
| JIM Elliott & SON Ltd | Construction | 2017 |
| Jireh Investments Limited | Health & social care | 2024 |
| JIW Consulting Limited | Extraterritorial | 2013 |
| Jj's Kitchen Looe Ltd | Hospitality | 2026 |
| Jj's Liskeard Ltd | Hospitality | 2022 |
| JJS Bar Looe Ltd | Hospitality | 2026 |
| JKM HR Consulting Limited | Public administration | 2016 |
| JL Planning (SW) Ltd | Professional & scientific | 2021 |
| JM Equipment Ltd | Wholesale & retail | 2014 |
| John Harris Financial Services Ltd | Financial services | 2016 |
| JON Searle Ltd | Administrative & support | 2021 |
| Joyroi Ltd | Information & communication | 2024 |
| JR Logistics Group Ltd | Transport & logistics | 2026 |
| Jtbn Developments Ltd | Construction | 2014 |
| Juliet Dawn Music Ltd | Extraterritorial | 2014 |
| Justjera Ltd | Wholesale & retail | 2021 |
| JW Mechanical, Electrical & Controls Ltd | Other services | 2019 |
| K & C Crane Services Ltd | Manufacturing | 2011 |
| K & S Agricultural Services Limited | Agriculture & fishing | 2011 |
| K R Holwill Limited | Construction | 2003 |
| K R P Electrical Limited | Construction | 2008 |
| Kabula Limited | Other services | 2018 |
| Kaddy Enterprises and Solutions Limited | Professional & scientific | 2017 |
| Karrek Parc Management Company Limited | Households | 2022 |
| Katim Investments Limited | Real estate | 2013 |
| Kazuki Films Ltd | Arts & recreation | 2025 |
| KD3 Consulting Limited | Information & communication | 2013 |
| Keason Plant Services Limited | Manufacturing | 2003 |
| Keever Limited | | 1985 |
| Kellows Ltd | Hospitality | 2017 |
| Kernewek Properties Limited | Real estate | 2024 |
| Kernow Architectural Services Ltd | Professional & scientific | 2024 |
| Kernow Brunch Box Ltd | Hospitality | 2024 |