| H.S.T Cornwall Limited | Construction | 2025 |
| Hamilton Place Management Limited | Households | 1997 |
| Handford Landscaping Limited | Administrative & support | 2024 |
| Hanks Enterprises Ltd | Other services | 2025 |
| Happy Boba Limited | Hospitality | 2025 |
| Harbour Court (Portreath) Residents Association Limited | Households | 1989 |
| Harbour Court Flats (Falmouth) Limited | Households | 1972 |
| Harbour House (Wadebridge) Limited | Real estate | 2009 |
| Harbour House RTM Company Limited | Households | 2008 |
| Harbour View Falmouth Limited | Hospitality | 2011 |
| Harness Data Intelligence Ltd | Information & communication | 2016 |
| Harris Roofing and Property Services Ltd | Construction | 2024 |
| Hartreeworks Ltd | Information & communication | 2017 |
| Hayes ISW Ltd | Health & social care | 2026 |
| Hayesgalleries Ltd | Arts & recreation | 2022 |
| Health HQ Limited | Health & social care | 2012 |
| Heartlands Trust | Wholesale & retail | 2010 |
| Heathen Brewery Ltd | Manufacturing | 2021 |
| Heavy Friends Limited | Arts & recreation | 2019 |
| Helford Developments Ltd | Construction | 2024 |
| Helidecks SA Limited | Administrative & support | 2016 |
| Helios Construction Ltd | Construction | 2020 |
| Hello Cakes Ltd | Manufacturing | 2019 |
| Henharrier Holdings Limited | Financial services | 2019 |
| Henlys Bar and Restaurant Limited | Hospitality | 2018 |
| Henrys Restaurant Bath Limited | Hospitality | 2016 |
| Herniss Farm Developments Ltd | Extraterritorial | 2021 |
| High Sierra Films Ltd | Information & communication | 2015 |
| Higher Spargo Farm Enterprises Ltd | Agriculture & fishing | 2023 |
| Hirach Ltd | Hospitality | 2023 |
| Histed & Roberts Limited | Health & social care | 2006 |
| Histo Services Limited | Health & social care | 2018 |
| Hoardboard Ltd | Wholesale & retail | 2021 |
| Holman Fraser Limited | Water & waste | 1999 |
| Homequest Limited | Real estate | 2008 |
| Horbury Gated Limited | Construction | 2022 |
| House of Hemp Limited | Manufacturing | 1993 |
| Hudd Properties LLP | | 2011 |
| Hunni Ltd | Information & communication | 2020 |
| Huntington Skye Ltd | Real estate | 2024 |
| HVL Limited | Financial services | 1999 |
| Hwel Ltd | Construction | 2022 |
| Hydration Care Consultancy Limited | Health & social care | 2018 |
| Hypha Knowledge Integration Limited | Information & communication | 2020 |
| Icare Planning Ltd | Health & social care | 2026 |
| ICT Southwest Ltd | Information & communication | 2010 |
| Impossible Immersive Ltd | Arts & recreation | 2026 |
| Impossible Producing CIC | Arts & recreation | 2020 |
| Incredible Oceans CIC | Professional & scientific | 2022 |
| Infocus Consulting Ltd | Professional & scientific | 2018 |
| Ingram Building & Maintenance Services Ltd | Construction | 2018 |
| Innovibe Ltd | Wholesale & retail | 2018 |
| International Breakers Ltd | Wholesale & retail | 2018 |
| International Business Consultancy Ltd | Professional & scientific | 2018 |
| Intersignia Limited | Information & communication | 2010 |
| IQ Property Solutions Limited | Real estate | 2024 |
| Iron House Ventures Limited | Construction | 2015 |
| Ironclad Roofing Limited | Construction | 2025 |
| Istar Group UK Ltd | Administrative & support | 2022 |
| IT Technologies SW Limited | Information & communication | 2004 |
| ITT Events Limited | Manufacturing | 2019 |
| J D Acrylics Limited | Manufacturing | 2012 |
| J Dudley Foods (Cornwall) Limited | Hospitality | 2019 |
| J. Brodie Luke Limited | Construction | 2002 |
| J.M.C.M. Ltd | Construction | 2010 |
| J.P.P. Developments Limited | Real estate | 2017 |
| Jack Franklin Limited | Information & communication | 2013 |
| Jack's Trading Co Ltd | Manufacturing | 2019 |
| Jackie George Ltd | Professional & scientific | 2024 |
| JAM Hill Limited | Wholesale & retail | 2010 |
| James Baker Property Ltd | Real estate | 2019 |
| James Bowden Photography Ltd | Professional & scientific | 2013 |
| James Campbell Brewery Services Limited | Professional & scientific | 2025 |
| JAY Flaxman Studio Ltd | Arts & recreation | 2017 |
| JD Polston Consulting Limited | Professional & scientific | 2017 |
| Jemma Goodman Design Ltd | Professional & scientific | 2023 |
| Jenkin Court Management (Newquay) Limited | Households | 1990 |
| JHH Construction Ltd | Construction | 2024 |
| JHH Property Limited | Real estate | 2019 |
| JL Smile Ltd | Health & social care | 2022 |
| Jmfr Ltd | Professional & scientific | 2017 |
| JO Sawmills Ltd | Manufacturing | 2010 |
| John Stone Digger Hire Ltd | Construction | 2015 |
| Johnrpom Services Ltd | Professional & scientific | 2018 |
| Jolly Sailor (Looe) Ltd | Hospitality | 2022 |
| Jolly Sailor Strength & Conditioning Ltd | Arts & recreation | 2014 |
| Josh Harris Electrical Ltd | Construction | 2025 |
| Jubilee Garage (Falmouth) Ltd | Wholesale & retail | 2022 |
| Judson Research Ltd | Professional & scientific | 2023 |
| Juggle Nation (Coates House) Limited | Construction | 2017 |
| Jumblies Day Nursery | Education | 2007 |
| Jumping Jelly Beans Ltd | Health & social care | 2019 |
| Just Engines Online Limited | Wholesale & retail | 2011 |
| K & M Building and Landscaping Services Ltd | Construction | 2023 |
| K & S Angels Day Nursery Ltd | Health & social care | 2015 |
| K&K Maritime LLP | | 2018 |
| Kairos Chiro Ltd | Health & social care | 2026 |
| Karow Ltd | Information & communication | 2022 |
| Kaspar Films Ltd | Information & communication | 2018 |
| KC Overseas Holdings Limited | Professional & scientific | 1974 |