| Hatm Limited | Administrative & support | 2017 |
| Hatton Textiles International Limited | Wholesale & retail | 2000 |
| Hautot Developments Limited | Construction | 2015 |
| Hautot Holdings Limited | Financial services | 2015 |
| Hautot Limited | Hospitality | 2014 |
| Haven Banks Management Company Limited | Households | 1989 |
| Haven Investments Limited | Real estate | 1946 |
| Hawarden Smith Group Limited | Financial services | 2021 |
| Hawarden Smith Investments LLP | | 2021 |
| Hawarden Smith Property Limited | Real estate | 2017 |
| Hawke Construction and Project Management Ltd | Construction | 2025 |
| Hawkerland Edge Ltd | Arts & recreation | 2026 |
| Hawkins Carpentry (Devon) Ltd | Manufacturing | 2024 |
| Hawkmoor Parke Management Company Limited | Households | 1995 |
| Hawksden Ltd | Wholesale & retail | 2023 |
| Hawksmoor Fund Managers Limited | Extraterritorial | 2016 |
| Hawksmoor Group Limited | Financial services | 2009 |
| Hawksmoor Investment Management Limited | Financial services | 2007 |
| HAY Tax Limited | Professional & scientific | 2002 |
| Haybarn Writing Limited | Arts & recreation | 2026 |
| Haydn Fine Ltd | Real estate | 2013 |
| Haydn Fine Recruitment Limited | Administrative & support | 2023 |
| Hayes CR UK Ltd | Administrative & support | 2023 |
| Hayes END Limited | Hospitality | 2021 |
| Hayes Grange LLP | | 2015 |
| Hayes Partners Ltd | Real estate | 2025 |
| Haygain Limited | Professional & scientific | 2023 |
| Hayley Cameron Consultancy Ltd | Professional & scientific | 2019 |
| Haymaker-Films Limited | Information & communication | 2025 |
| Hayne Barton Properties Ltd | Hospitality | 2020 |
| Hayne Lane Limited | Administrative & support | 2020 |
| Hayne Quarry Ltd | Mining & quarrying | 2024 |
| Haytor Rentals Ltd | Real estate | 2019 |
| Hayudomo HM Trading Limited | Wholesale & retail | 2013 |
| Haywards Property Developments Ltd | Construction | 2023 |
| Hayzee Ltd | Construction | 2023 |
| Hazeldent Ltd | Health & social care | 2026 |
| Hazelsfield Limited | Agriculture & fishing | 2019 |
| Hazelwood Farms LLP | | 2022 |
| Hazelwood Motor Company Ltd | Professional & scientific | 2012 |
| Hazlewood Riviera Limited | Manufacturing | 2023 |
| Hbat Management Limited | Professional & scientific | 2024 |
| HBM Services Ltd | Professional & scientific | 2026 |
| HBP Haci Limited | Hospitality | 2026 |
| HC Planning Ltd | Professional & scientific | 2023 |
| HCT Turf LLP | | 2013 |
| HCW Property Limited | Real estate | 2024 |
| Head Hair & Beauty Limited | Other services | 2018 |
| Headband Limited | Arts & recreation | 1994 |
| Headforwards Group Limited | Financial services | 2022 |
| Headland Finance Limited | Other services | 1996 |
| Headlight Consultancy Limited | Professional & scientific | 2022 |
| Headline Property Ltd | Real estate | 2022 |
| Headlines Exmouth Limited | Other services | 2019 |
| Headstart Exeter Limited | Other services | 2018 |
| Headway Capital Ltd | Financial services | 2024 |
| Headway Devon | Health & social care | 2003 |
| Headway Homes Ltd | Real estate | 2024 |
| Headway Properties Essex Ltd | Real estate | 2021 |
| Headway Property Developments Ltd | Real estate | 2023 |
| Headway Property Investments Ltd | Real estate | 2017 |
| Heale Limited | Wholesale & retail | 2021 |
| Health Opportunities Devon CIC | Health & social care | 2023 |
| Health S.P.A. Consulting Ltd | Professional & scientific | 2019 |
| Healthcare Analysts Limited | Information & communication | 2017 |
| Healthcare Improvement Designs Limited | Professional & scientific | 2025 |
| Healthfoods Planet Limited | Hospitality | 2021 |
| Heart Felt Recovery CIC | Health & social care | 2024 |
| Heartbreakers Hair Co Ltd | Other services | 2022 |
| Hearthstone Homes Limited | Real estate | 2021 |
| Heartvet Consultants Limited | Professional & scientific | 2010 |
| Heartvet Solutions Limited | Professional & scientific | 2023 |
| Heartvets EOT Limited | Professional & scientific | 2024 |
| Heat Again Limited | Construction | 2022 |
| Heat Tweaks Limited | Construction | 2014 |
| Heatex Solutions Ltd | Construction | 2019 |
| Heathfield Commercials SW Ltd | Manufacturing | 2015 |
| Heathfield Medical Limited | Health & social care | 2021 |
| Heathfield Rentals Limited | Real estate | 1983 |
| Heating Simply Limited | Professional & scientific | 2026 |
| Heatology Limited | Construction | 2009 |
| Heaton Financial Independent Financial Advisers Ltd | Professional & scientific | 2010 |
| Heavenly Retreats Limited | Hospitality | 2022 |
| Heavens Whisper Ltd | Information & communication | 2021 |
| Heavitree Health Spa Ltd | Other services | 2025 |
| Heavitree Inns Limited | Hospitality | 1991 |
| Heavitree Limited | Hospitality | 2019 |
| Heavitree Manor Limited | Real estate | 2022 |
| Heavitree Osteopaths Limited | Health & social care | 2015 |
| Heavitree Social Club Ltd | Hospitality | 1982 |
| Heavitree Stores | | 2003 |
| Heavy Hire Limited | Administrative & support | 2011 |
| Heavy Repping Ltd | Wholesale & retail | 2022 |
| Heavy Tree Ltd | Hospitality | 2025 |
| Hedgd Limited | Information & communication | 2016 |
| Hedgerow Living Limited | Hospitality | 2026 |
| Hedgerow Print Limited | Manufacturing | 2006 |
| Hedland Ltd | Administrative & support | 2025 |
| Heera Cash & Carry Ltd | Wholesale & retail | 2024 |
| Heera International Foods Ltd | Wholesale & retail | 2024 |