| Harbrook Development Limited | Real estate | 1973 |
| Hardstone Devon Limited | Manufacturing | 2017 |
| Harrop & Associates (DE) Limited | Construction | 2019 |
| Harrop & Associates (Marple) Limited | Real estate | 2005 |
| Hartley Limited | Professional & scientific | 2006 |
| Hazelcott Ltd | Administrative & support | 2022 |
| Hedgerow Marketing Limited | Professional & scientific | 2015 |
| Herlsh Limited | Financial services | 2025 |
| HGR Experts Limited | Real estate | 2022 |
| Higgins Peters Limited | Professional & scientific | 2021 |
| Higher Teignmouth Farm Ltd | Agriculture & fishing | 2022 |
| Highfield Amenity 2 Limited | Extraterritorial | 2011 |
| Hills Heating Ltd | Construction | 2019 |
| Hollyhocks (South West) Ltd | Wholesale & retail | 2012 |
| Holmes Care Assessments Consultancy Ltd | Health & social care | 2016 |
| Home Farm Combeinteignhead Ltd. | Construction | 2014 |
| Homes for ALL Investments Limited | Households | 2015 |
| Honeyacre Farm Ltd | Agriculture & fishing | 2023 |
| Honeycacao Ltd | Manufacturing | 2018 |
| Horology Design Limited | Arts & recreation | 2008 |
| Horsemanship for Health UK CIC | Education | 2016 |
| House of Fizzy Limited | Arts & recreation | 2025 |
| Housource Ltd | Real estate | 2024 |
| Howard Bruce Ltd | Construction | 2015 |
| Hubs Work Ltd | Information & communication | 2026 |
| HUG & Fable Ltd | Wholesale & retail | 2025 |
| Hughes Shoes Limited | Agriculture & fishing | 2016 |
| Huppenstop Limited | Professional & scientific | 2014 |
| Hydroflow Limited | Extraterritorial | 2014 |
| IAN Livingstone Consulting Limited | Professional & scientific | 2015 |
| Ibrahim Hotel Restaurant Limited | Hospitality | 2012 |
| Idea Strategy and Design Ltd | Information & communication | 2025 |
| Ikigai Miscellany Community Interest Company | Arts & recreation | 2022 |
| Ilearn School of Motoring Ltd | Education | 2020 |
| Ilsham House Management Company Limited | Households | 1982 |
| Impact ME Limited | Information & communication | 2015 |
| Importas Limited | Wholesale & retail | 2005 |
| IN Safe Hands UK & Europe Ltd | Other services | 2018 |
| Inchanga Residents Management Company Limited | Households | 1986 |
| Indoor Air Services Limited | Professional & scientific | 2022 |
| Inertia Group SW Ltd | Financial services | 2026 |
| Inkpad Architecture Ltd | Professional & scientific | 2016 |
| Inn Education Ltd | Education | 2025 |
| Innes & Stone Consultancy Limited | Administrative & support | 2018 |
| Innovatehealth Africa Ltd | Information & communication | 2025 |
| Inspirations Advertising and Design Limited | Professional & scientific | 2004 |
| Inspire Lifestyle Management Ltd | Administrative & support | 2022 |
| Inspired Computer Solutions Limited | Information & communication | 1996 |
| Inspired Occasions Ltd | Arts & recreation | 2022 |
| Inspired Property Services Limited | Construction | 2001 |
| Inspireplay Ltd | Education | 2018 |
| Instruckt Ltd | Education | 2022 |
| Investment Company Plc(The) | Financial services | 1868 |
| Invstr Holdings Ltd | Financial services | 2020 |
| IPA Fishing Limited | Agriculture & fishing | 1990 |
| IQ Engineering Consultants Limited | Information & communication | 2009 |
| Isca Administration Services Limited | Administrative & support | 2014 |
| Isca Energy Limited | Professional & scientific | 2025 |
| IVY Cabs Limited | Transport & logistics | 2009 |
| IVY Education Trust | Education | 2011 |
| IVY Educational Services Limited | Education | 2011 |
| IVY House Freehold Limited | Households | 2012 |
| J B Ceramics Limited | Construction | 2007 |
| J F Plant Engineering Limited | Manufacturing | 2009 |
| J Morgan Consultancy Ltd | Information & communication | 2016 |
| J&G Aerospace Limited | Manufacturing | 2015 |
| J2K Partnership LLP | | 2023 |
| Jabsportes Ltd | Arts & recreation | 2017 |
| Jack James Properties Ltd | Real estate | 2026 |
| Jackmans ALL Seasons Ltd | Wholesale & retail | 2018 |
| Jackmans Store Box Limited | Other services | 2025 |
| Jason's Garden Ltd | Hospitality | 2023 |
| Jcbc (South West) Ltd | Construction | 2020 |
| Jcbc Holdings Ltd | Construction | 2024 |
| Jennerco Limited | Financial services | 2019 |
| Jennifer Roder Limited | Education | 2004 |
| JL Construction (SW) Limited | Construction | 2022 |
| JL Gibbins Ltd | Hospitality | 2025 |
| John Mayne Stonemasonry Limited | Manufacturing | 2014 |
| John Roder Limited | Information & communication | 2003 |
| Jolt Creative Ltd | Arts & recreation | 2011 |
| JON Axford Golf Ltd | Wholesale & retail | 2023 |
| Jones and West Limited | Professional & scientific | 2011 |
| JP Heating & Bathrooms Ltd | Wholesale & retail | 2014 |
| JR Teignmouth Limited | Other services | 2024 |
| JS Financial Consultancy Limited | Financial services | 2005 |
| Jtldreams Ltd | Hospitality | 2024 |
| Jwhockin Ltd | Other services | 2025 |
| Kaythorn Property Ltd | Real estate | 2015 |
| Kazbern Limited | Wholesale & retail | 2004 |
| Kdmg Ltd | Professional & scientific | 2016 |
| Kempston Holdings Ltd | Financial services | 2026 |
| Kind Threads Ltd | Wholesale & retail | 2023 |
| Kingfisher Associates (Consultants) Ltd | Professional & scientific | 2013 |
| Kings ASH Kitchens and Interiors Ltd | Wholesale & retail | 2021 |
| Kingsland Leisure Ltd | Real estate | 2022 |
| Kingsley Projects Limited | Professional & scientific | 2002 |
| Kingsway Community Enterprises | Arts & recreation | 2006 |
| Know Insight Ltd | Information & communication | 2010 |
| Kodasocial.Co.Uk Ltd | Information & communication | 2026 |