| Heathcoat Yarns & Fibres Limited | Professional & scientific | 1948 |
| Heathfield Terminal Company Limited | Extraterritorial | 1978 |
| Heaver Brothers Limited | Transport & logistics | 2002 |
| Heddon Management Limited | Construction | 1996 |
| HEI Electrical Ltd | Wholesale & retail | 2004 |
| Helado Ltd | Professional & scientific | 2006 |
| Helnick Limited | Other services | 2002 |
| Heltor Limited | Wholesale & retail | 1961 |
| Hemmings Coaches Limited | Transport & logistics | 2004 |
| Hempowered Pets Limited | Wholesale & retail | 2023 |
| Herbavet (UK) Limited | Wholesale & retail | 1998 |
| Heronbay Developments Limited | Construction | 1999 |
| Heyford House Day Spa Ltd | Other services | 2008 |
| Hidene Limited | Extraterritorial | 2000 |
| Higher Holcombe Ltd | Hospitality | 2018 |
| Higher Wiscombe Limited | Hospitality | 2004 |
| Highfield Manor Limited | Construction | 2003 |
| Highway Management Services Limited | Professional & scientific | 1982 |
| Hill Farm Cottages Ltd | Hospitality | 2018 |
| Hill's of Woodmancote Limited | Hospitality | 2003 |
| Hills Services Limited | Transport & logistics | 2004 |
| Hime Properties Ltd | Construction | 2004 |
| Hinobis Ltd | Transport & logistics | 2018 |
| Holemoor Properties Limited | Construction | 1997 |
| Holiday Finance 2000 Limited | Professional & scientific | 1999 |
| Holley Close Conservation Limited | Real estate | 2006 |
| Holliss Filling Stations Limited | Wholesale & retail | 2003 |
| Holmacott Landfill Site & Recycling Centre Limited | Water & waste | 2003 |
| Holmes Farm (Spaxton) Limited | Agriculture & fishing | 1955 |
| Home Direct South West Limited | Wholesale & retail | 2002 |
| Home-Brew-Hopshop.Co.Uk Ltd | Wholesale & retail | 2006 |
| Hong Kong Cornwall Square Limited | Construction | 2016 |
| Honiton & District Carnival | Arts & recreation | 1995 |
| Honiton Concrete Limited | | 1974 |
| Hoopbray Limited | Professional & scientific | 1987 |
| Horizons (Plymouth) | Arts & recreation | 2002 |
| Horrell Builders Ltd | Construction | 2003 |
| Horseford Specialist Cleaning Services Limited | Administrative & support | 2005 |
| Hoskins Minerals Limited | | 1964 |
| Hotel Elizabeth Limited | Professional & scientific | 2004 |
| Houndiscombe Consultants Limited | Professional & scientific | 2001 |
| House Avenue Management Company Limited | Households | 2000 |
| Housewares (Sidmouth) Ltd. | Wholesale & retail | 2003 |
| Howe and Davis Limited | Extraterritorial | 1949 |
| Howen Investment Company Limited | Financial services | 1959 |
| Hudson Holbrook Holdings Limited | | 1987 |
| Hudsons Trading Limited | Wholesale & retail | 2003 |
| Huila Ltd | Other services | 2024 |
| Hylo Automated Parking Limited | Manufacturing | 1989 |
| IAN MAY Limited | Education | 2006 |
| ICG Baker Limited | Construction | 2003 |
| Ignite Corporate Development Limited | Professional & scientific | 2004 |
| Ilfracombe Cleaning Services Limited | Administrative & support | 2003 |
| Imperial House Management Company Limited | Households | 1999 |
| Imprint (Print and Design) Limited | | 1974 |
| IMT Contracting Ltd | Other services | 2023 |
| IN 2 Computers Limited | Extraterritorial | 2005 |
| IN 2 Networks Limited | Information & communication | 2005 |
| In-Touch (South West) Limited | Transport & logistics | 1991 |
| Indellvin Ltd | Administrative & support | 2007 |
| Indulgent Hotels Limited | Hospitality | 2006 |
| Indus Biomedica (U.K.) Limited | Professional & scientific | 1988 |
| Infocus Enterprises Limited | Hospitality | 2016 |
| Inkost Ltd. | Wholesale & retail | 1996 |
| Insideout Home Ltd | Wholesale & retail | 2006 |
| Intercover (Insurance Consultants) Limited | | 1981 |
| Investacast Ilfracombe Ltd. | Professional & scientific | 2005 |
| Isaacs Surveying Ltd | Professional & scientific | 2025 |
| Isca Agriculture Limited | Construction | 2003 |
| Isca Scaffold Limited | Construction | 1992 |
| Ivor Doble Limited | Wholesale & retail | 1959 |
| Ivor Jones & Co. Ltd. | Financial services | 1973 |
| Ivorian Catering Ltd | Other services | 2022 |
| J & T Hackney Carriage Limited | Transport & logistics | 2007 |
| J G W Management Limited | Professional & scientific | 2002 |
| J R Transport & Sons Limited | Transport & logistics | 2000 |
| J V Pengelly Building Ltd | Construction | 2007 |
| J&Jl 2026 Limited | Real estate | 2026 |
| J. Hoare & Sons | | 1999 |
| J. P. Leisure Ltd | Administrative & support | 2007 |
| J.& F.J.Baker & Company Limited | Manufacturing | 1896 |
| J.A.C. Building and Civil Engineering Limited | | 1985 |
| J.C.Sharpe Limited | Wholesale & retail | 1965 |
| J.E.Stacey & Co.Limited | Construction | 1959 |
| J.K.S. Floorings Limited | Construction | 1973 |
| J.P. Civil Engineering & Surveying Limited | Construction | 2002 |
| J.T. White (Builders) Limited | | 1974 |
| J.T.S. (Wholesale) Carpets Limited | Transport & logistics | 1989 |
| J.Y.Coles & Sons Limited | Construction | 1954 |
| JAB Networked Solutions Limited | Information & communication | 1999 |
| Jackman SW Limited | Construction | 1996 |
| Jackmans Tackle Limited | Wholesale & retail | 2004 |
| Jackmans Toybox Limited | Wholesale & retail | 1999 |
| Jackson Construction Management Limited | Extraterritorial | 1997 |
| Jackson Limited | Wholesale & retail | 1951 |
| Jackson Spencer & Charles Limited | Hospitality | 1963 |
| Jakes Limited | Hospitality | 2001 |
| James Mccormick Photography Ltd | Professional & scientific | 2015 |
| James on Line Limited | Wholesale & retail | 2002 |
| James Roland Bartram Ltd | Other services | 2007 |