| Happy Camel CIC | Education | 2023 |
| Happy Ever After Ltd | Extraterritorial | 2023 |
| Happy Fulfilment UK Ltd | Transport & logistics | 2025 |
| Happy Kids Collective Limited | Wholesale & retail | 2025 |
| Happy Pets Dog Day Care Limited | Professional & scientific | 2025 |
| Happy Scent Co Limited | Wholesale & retail | 2022 |
| Happyccino Ltd | Hospitality | 2019 |
| Harbour Arch Quay Limited | Real estate | 2007 |
| Harbour Arch Quay Management Company Limited | Real estate | 2019 |
| Harbour Crest Holdings Ltd | Households | 2026 |
| Harbour House Holidays Limited | Extraterritorial | 2009 |
| Harbour Lights Developments Limited | Construction | 2020 |
| Harbour Lights Media Limited | Information & communication | 2013 |
| Harbour Pizza Limited | Hospitality | 2025 |
| HARBOUR8 Limited | Hospitality | 2017 |
| Harbourside Court Management Company Limited | Households | 1984 |
| Harbourside Huts Limited | Construction | 2021 |
| Harbourside Lettings Plymouth Ltd | Real estate | 2021 |
| Harbourstone Mortgages Limited | Financial services | 2025 |
| Harbron Group Services Ltd | Administrative & support | 2018 |
| Harbron Home Improvements Ltd | Construction | 2011 |
| Hardcastles Property Services Ltd | Real estate | 2000 |
| Harding & Sons,Limited | Wholesale & retail | 1929 |
| Harding Facilities Limited | Real estate | 2024 |
| Harding Group South West Ltd | Construction | 2026 |
| Harding Plymouth Limited | Hospitality | 2019 |
| Hardman Capital Limited | Financial services | 2024 |
| Hardwick Farm Management Company Limited | Professional & scientific | 1996 |
| Hardwick Nurseries Property Limited | Real estate | 2018 |
| Hardy SW Ltd | Construction | 2016 |
| Hareston Hospitality Ltd | Hospitality | 2023 |
| Hareston Manor Weddings Ltd | Hospitality | 2020 |
| Hareston Mechanical Ltd | Professional & scientific | 2022 |
| Hargrave Media Limited | Administrative & support | 2020 |
| Harman Bagels Holdings Plymouth Limited | Financial services | 2024 |
| Harman Bagels Plymouth Limited | Hospitality | 2021 |
| Harman Bagels Totnes Limited | Hospitality | 2025 |
| Harmony Park Homes Ltd | Real estate | 2023 |
| Harmos Limited | Wholesale & retail | 2023 |
| Harold Duckworth & Co Limited | Professional & scientific | 2019 |
| Harold Heath Ltd | Construction | 2021 |
| Harper Construction Ltd | Construction | 2019 |
| Harris Bros. Holdings Limited | Financial services | 2023 |
| Harris Bros.(Billericay)Limited | Real estate | 1940 |
| Harris Composite Services Ltd | Manufacturing | 2025 |
| Harris Homes South West Ltd | Real estate | 2023 |
| Harris Hounds Dog Walking Ltd | Other services | 2023 |
| Harris Hounds Services Ltd | Other services | 2019 |
| Harrison Lessor Ltd | Construction | 2022 |
| Harrison Rigging Services Limited | Mining & quarrying | 2018 |
| Harrisons Builders Limited | Construction | 2002 |
| Harrowbeer Ltd | Real estate | 2026 |
| Harry's Café Plymouth Ltd | Hospitality | 2025 |
| Hart and Mind Limited | Professional & scientific | 2007 |
| Hart Marine Consultants Limited | Professional & scientific | 2011 |
| Hart Medics Limited | Health & social care | 2022 |
| Hart of Bookkeeping Limited | Professional & scientific | 2017 |
| Hartlands Management Company Limited | Households | 2019 |
| Hartlepool Properties Ltd | Real estate | 2018 |
| Hartley Construction Management Ltd | Professional & scientific | 2018 |
| Hartley Electronics Limited | | 1992 |
| Hartley Gardens Plymouth Management Limited | Households | 2018 |
| Hartley Park (Plymouth) Management Co. Limited | Households | 1978 |
| Hartley Park Freehold Ltd | Households | 2019 |
| Hartley Service Centre Limited | Wholesale & retail | 2012 |
| Harts Fascias & Roofing Company Ltd | Construction | 2022 |
| Harvella Builders Ltd | Construction | 2017 |
| Harvey Construction Management Ltd | Construction | 2025 |
| Harveys Surveyors Ltd | Professional & scientific | 2013 |
| Harveyson Forestry Limited | Agriculture & fishing | 2013 |
| Haskins Holdings Limited | Financial services | 2025 |
| Hasmar Retail Limited | Wholesale & retail | 2006 |
| Hastingswhitening Limited | Health & social care | 2025 |
| Hat-Trick Sales Promotion Limited | | 1988 |
| Hatch Marquee Hire (Holdings) Limited | Administrative & support | 2013 |
| Hatch Marquee Hire Limited | Administrative & support | 2004 |
| Hatch Masters Limited | Arts & recreation | 2020 |
| Hattam Carpenters Ltd | Construction | 2014 |
| Haulmark Property Management Limited | Real estate | 2026 |
| Hauss & Haven Ltd | Real estate | 2026 |
| Havana Plymouth Ltd | Hospitality | 2020 |
| Haven Accessories Ltd | Manufacturing | 2025 |
| Haven Recovery Housing CIC | Real estate | 2020 |
| Havencare Homes and Support Limited | Real estate | 1987 |
| Havenscape Ltd | Real estate | 2024 |
| Havsstad Media Ltd | Information & communication | 2020 |
| Hawkbridge Consultants Limited | Manufacturing | 2011 |
| Hawkins Cars Limited | Wholesale & retail | 2016 |
| Hawkmoor Close Limited | Households | 2017 |
| Hawkstone 2002 Limited | Real estate | 2002 |
| Hawthorn Scientific Ltd | Professional & scientific | 2024 |
| Hayden Property Holdings Limited | Real estate | 2020 |
| Hayes Construction SW Ltd | Construction | 2022 |
| Hayes END (West Hill) Management Company Limited | Households | 2016 |
| Hayle Community Rugby Facilities Limited | Construction | 2008 |
| Haylo Labs Limited | Financial services | 2025 |
| Haylo Ventures Limited | Professional & scientific | 2022 |
| Hayman Engineering Limited | Financial services | 2018 |
| HAZ Group SW Ltd | Construction | 2026 |
| Hazel Winston Holdings Limited | Financial services | 2022 |