| Hayes-Daugherty Limited | Health & social care | 2013 |
| Haynes and Marshall Limited | Other services | 2013 |
| Hazel Maxwell-Payne & Associates Limited | Administrative & support | 2010 |
| HC Developments (Exmouth) Ltd | Real estate | 2024 |
| Headsup Mental Health Awareness C.I.C. | Health & social care | 2018 |
| Health Advisor Limited | Information & communication | 2013 |
| Health MD Limited | Health & social care | 2023 |
| Healthy Estate Life Planning Limited | Other services | 2018 |
| Heathpark Service Station Limited | Wholesale & retail | 1993 |
| Hello Language Experiences Ltd | Education | 2026 |
| Hello Sidmouth Ltd | Education | 2026 |
| Heltor Plant Hire and Groundworks Limited | Construction | 2018 |
| Henley Studio Limited | Manufacturing | 2021 |
| Hennesy Holdings Ltd | Real estate | 2023 |
| Heritage Holdings Devon Limited | Financial services | 2024 |
| Heron Court Management Company (Exmouth) Limited | Households | 1975 |
| Hespera RTM Company Ltd | Households | 2019 |
| Hewart Electrical Limited | Construction | 2021 |
| Highbury Management Co. (Exmouth) Ltd. | Households | 1993 |
| Highcliffe (Exmouth) Flat Management Co. Limited | Households | 1986 |
| Highcliffe Court (Lympstone) Management Company Limited | Households | 1998 |
| Highfield Court and Ashley House Exmouth (Management) Limited | Households | 1994 |
| Highland Books Limited | Information & communication | 1995 |
| Highland Property Development (Exmouth) Ltd | Construction | 2011 |
| Hikura Ltd | Information & communication | 2025 |
| Hill Lane 2 Limited | Construction | 2024 |
| Hill Lane Properties Ltd | Construction | 2010 |
| Hillcrest (SW) Limited | Construction | 2021 |
| Hillcrest Construction & Developments Limited | Construction | 2017 |
| Hillcrest Management Company (Exmouth) Limited | Households | 2012 |
| Hillcrest Property Investments (SW) Limited | Real estate | 2024 |
| Hillside Court (Exmouth) Limited | Households | 1989 |
| Hillview Management Company (Sidford) Limited | Households | 2009 |
| Hindsight Capital Ltd | Professional & scientific | 2025 |
| Hireace Ltd | Information & communication | 2025 |
| Hirethings Ltd | Administrative & support | 2021 |
| HIS + Hers Plumbing & Heating Ltd | Construction | 2019 |
| HJS Property Group Limited | Real estate | 2021 |
| HMH Investments Group Ltd | Real estate | 2024 |
| HNC Accounting Solutions Limited | Professional & scientific | 2000 |
| Hoff and Sheppard Ltd | Wholesale & retail | 2024 |
| Holchar Properties Limited | Real estate | 2025 |
| Holloways Electrical Solutions Limited | Construction | 2020 |
| Holmes Timber Frame Design (SW) Limited | Administrative & support | 2006 |
| Home and Heart Living Ltd | Health & social care | 2025 |
| Home From Home Property Services Limited | Real estate | 2016 |
| Home in Town Ltd | Real estate | 2006 |
| Home-Start Exeter, East and MID Devon | Health & social care | 2006 |
| Homer Design Limited | Information & communication | 2008 |
| Honiton Storage Limited | Administrative & support | 2024 |
| Honu Ltd | Information & communication | 2014 |
| Hospitality Thirteen Ltd | Hospitality | 2023 |
| Hot Stuff Event Management Limited | Administrative & support | 2015 |
| Hotel Riviera Limited | Hospitality | 2023 |
| House of Cards 8288 Ltd | Wholesale & retail | 2025 |
| House of Thread Studio Ltd | Wholesale & retail | 2026 |
| Howard Properties Lettings Limited | Real estate | 2007 |
| Howes Homes Limited | Administrative & support | 2011 |
| Hudson Couriers Ltd | Transport & logistics | 2019 |
| Hunters Moon Hotel Limited | Hospitality | 2008 |
| Hypa-Consulting Limited | Professional & scientific | 2023 |
| I.K International Limited | Manufacturing | 2020 |
| IAN Crook Wealth Management Ltd | Financial services | 2011 |
| IBB Point Limited | Hospitality | 2026 |
| Ician IT Ltd | Extraterritorial | 2022 |
| ICO Developments Limited | Households | 2021 |
| Ideal Clothes Care Specialists & Laundry Limited | Manufacturing | 2022 |
| Ideal Commercial Laundry Limited | Manufacturing | 2021 |
| Identity UK (Retail) Limited | Administrative & support | 2013 |
| IG Water Research and Consultancy Limited | Professional & scientific | 2026 |
| Igeneration.Holdings Ltd | Professional & scientific | 2020 |
| Igeneration.Life Ltd | Professional & scientific | 2020 |
| Imagination Exchange Limited | Arts & recreation | 2022 |
| IMP Ideas Ltd | Professional & scientific | 2012 |
| Imperium Landscaping & Maintenance Ltd | Administrative & support | 2025 |
| Imperium Marketing Ltd | Professional & scientific | 2025 |
| Inanli Barber Grooming Limited | Other services | 2023 |
| Inchcoulter Management Company Limited | Households | 2001 |
| Inconf Ltd | Information & communication | 2020 |
| Infinite Property Assets Ltd | Real estate | 2022 |
| Infinity SW Ltd | Wholesale & retail | 2018 |
| Infinitystay Ltd | Hospitality | 2023 |
| Inn the Village Ltd | Hospitality | 2016 |
| Innerlimits Foundation | Arts & recreation | 2010 |
| Innerlimits Limited | Arts & recreation | 2002 |
| Instruct Media Limited | Other services | 2025 |
| Insurastore.Com Limited | Financial services | 2007 |
| Insurastore.Com LLP | | 2006 |
| Interdesign Pharmcare Ltd | Construction | 2010 |
| Inverter Fusion Limited | Manufacturing | 1991 |
| Investment Land Causeway Ltd | Construction | 2025 |
| Investment Land Ltd | Real estate | 2018 |
| Investment Land Marsh Farm Ltd | Construction | 2025 |
| Investment Land ST Giles Ltd | Construction | 2024 |
| Ipexit Ltd | Information & communication | 2018 |
| Isaac Property Investments Limited | Real estate | 2016 |
| Isard Developments Limited | Real estate | 1971 |
| Iuvenis Ltd | Administrative & support | 2023 |
| J and H Consultancy Services Limited | Professional & scientific | 2021 |
| J Goodfellow Roofing Limited | Construction | 2018 |