| Haprondigital Ltd | Information & communication | 2024 |
| Haraa Limited | Wholesale & retail | 2015 |
| Harborne Maine Limited | Other services | 2015 |
| Hardcore Munch Ltd | Hospitality | 2025 |
| Hardie's Property Lettings Ltd | Real estate | 2020 |
| Hardman Education Limited | Professional & scientific | 2016 |
| Hardtops UK Limited | Wholesale & retail | 2013 |
| Hardwick Farms (Suffolk) Limited | Wholesale & retail | 1998 |
| Hardwick Homes (Developments) Limited | Construction | 2018 |
| Hardwick Homes (Property) Ltd | Real estate | 2023 |
| Hardwick Homes (Swindon) Limited | Real estate | 2015 |
| Hardwick House (Nominees) Limited | Professional & scientific | 2007 |
| Hardwicke. Ltd | Construction | 2020 |
| Hardwired Studios Ltd | Information & communication | 2018 |
| Hared Ltd | Transport & logistics | 2025 |
| Harford’S Holdings Ltd | Real estate | 2025 |
| Hargreaves Road Management Limited | Households | 2002 |
| Harish Properties Ltd | Real estate | 2021 |
| Harish Supermarket Ltd | Wholesale & retail | 2018 |
| Harlequin Playgrounds Ltd | Construction | 2022 |
| Harley Cafe Limited | Hospitality | 2014 |
| Harley Country Lifestyle Limited | Wholesale & retail | 2014 |
| Harley House Rental Services Ltd | Real estate | 2014 |
| Harman Electrical (Swindon) Ltd | Construction | 2024 |
| Harman Electrical Limited | Construction | 2008 |
| Harman's REG Ltd | Wholesale & retail | 2019 |
| Harmell Ltd | Information & communication | 2024 |
| Harmisha Limited | Construction | 2019 |
| Harmoney Financial Ltd | Professional & scientific | 2019 |
| Harmony (Melksham) Limited | Education | 2016 |
| Harmony Equitation Limited | Arts & recreation | 2019 |
| Harmony Health Retreat & Spa Ltd | Administrative & support | 2024 |
| Harper Project Management Specialists Ltd | Information & communication | 2014 |
| Harpers Aggregates & Landscaping Limited | Administrative & support | 2025 |
| Harrimat Services Ltd | Health & social care | 2022 |
| Harris & Anderson Praxis Solutions Ltd | Administrative & support | 2026 |
| Harris and Sons (Swindon) Limited | Real estate | 2025 |
| Harris Change Management Services Ltd | Professional & scientific | 2020 |
| Harris Enterprises Limited | Wholesale & retail | 2015 |
| Harrison Rich Ltd | Wholesale & retail | 2025 |
| Harrison Taverns UK Ltd | Administrative & support | 2018 |
| Harrods Property Management Ltd | Real estate | 2021 |
| Harrowby 040 Cardiff Management Company Limited | Households | 2004 |
| Harrowby Street 1 RTM Company Limited | Households | 2021 |
| Harrowby Street 2 RTM Company Limited | Households | 2021 |
| Harry & Sons Haulage Ltd | Transport & logistics | 2019 |
| Harry Alexander Limited | Administrative & support | 2018 |
| Harry Dhillon Haulage Ltd | Transport & logistics | 2020 |
| Harryburn Wind Farm Limited | Extraterritorial | 2016 |
| Harson Property Limited | Real estate | 2006 |
| Hart Close (Wootton Bassett) RTM Company Limited | Households | 2016 |
| Hart Composite Solutions Ltd | Manufacturing | 2026 |
| Hart Ketogenic Clinic Limited | Health & social care | 2015 |
| Hart of AK Ltd | Hospitality | 2021 |
| Hart Street Properties Limited | Real estate | 2001 |
| Harthill Consulting Ltd | Professional & scientific | 2002 |
| Harthill Ltd | Professional & scientific | 2019 |
| Harthill Partnerships Limited | Professional & scientific | 2021 |
| Hartland Interiors Limited | Construction | 2012 |
| Harvest Health Limited | Health & social care | 2011 |
| Harvey & Gore (Antiques) Limited | Administrative & support | 1969 |
| Harvey One Limited | Wholesale & retail | 2019 |
| Harvey Scotts Limited | Hospitality | 2009 |
| Harvey-Samuel Property Ltd | Extraterritorial | 2022 |
| Harwell Ltd | Real estate | 2016 |
| Hasegan Trans Ltd | Transport & logistics | 2017 |
| Hashvi Limited | Real estate | 2022 |
| Haskins 1999 Limited | Professional & scientific | 1998 |
| Hatfield Aerodrome (Management) Limited | Real estate | 2001 |
| Hatfield Business Park Management Limited | Real estate | 1992 |
| Hato Labo (UK) Ltd | Extraterritorial | 2014 |
| Hatrick Media Limited | Professional & scientific | 2016 |
| Haus of Pulchritude Ltd | Other services | 2026 |
| Hawk Group Limited | Professional & scientific | 2025 |
| Hawk Insulation Limited | Construction | 2014 |
| Hawkcentral Limited | Extraterritorial | 1988 |
| Hawkeye Financial Limited | Financial services | 2018 |
| Hawkeye Wills Ltd | Other services | 2024 |
| Hawkins and Young Limited | Construction | 2003 |
| Hawkins Project Services Ltd | Construction | 2026 |
| Hawksridge Roofing & Building Ltd | Construction | 2023 |
| Hawson Media Limited | Information & communication | 2018 |
| Hayaanisaa Ltd | Wholesale & retail | 2025 |
| Haydon Builders Ltd | Other services | 2023 |
| Haydon Court (North) Residents Company Limited | Households | 1974 |
| Haydon Court (West) Residents Company Limited | Households | 1975 |
| Haydon Development Company Limited | Construction | 1987 |
| Haydon Wick PUB Limited | Hospitality | 2016 |
| Haynes Horseboxes Limited | Wholesale & retail | 2021 |
| Hayven Limited | Real estate | 2024 |
| Hayward & Hughes Ltd | Construction | 2023 |
| Hayward Care (Swindon) Ltd | Health & social care | 2018 |
| Hayzekial Limited | Health & social care | 2021 |
| Hazara Trade Ltd | Wholesale & retail | 2024 |
| Haze Property Ltd | Real estate | 2025 |
| Hazel and Norah Company Limited | Health & social care | 2025 |
| Hazlo Consulting Ltd | Professional & scientific | 2021 |
| Hazwell Ltd | Information & communication | 2014 |
| HBH Property & Letting Ltd | Real estate | 2024 |
| HBT Carpentry Ltd | Construction | 2025 |