| Harlequin Pizza House Ltd | Hospitality | 2025 |
| Harley Road Management Company Limited | Households | 2005 |
| Harley Street Developments Limited | Real estate | 2019 |
| Harley Street Studio Limited | Health & social care | 2020 |
| Harley Street Surgery Limited | Professional & scientific | 2015 |
| Harley's Unicorn Limited | Hospitality | 2019 |
| Harleys Transport Limited | Transport & logistics | 2012 |
| Harling & SON Limited | Wholesale & retail | 2024 |
| Harlo Recruitment Ltd | Administrative & support | 2025 |
| Harlow Grange Park Management Company Limited | Households | 1997 |
| Harlow Medico Legal Limited | Other services | 2013 |
| Harlow Oval Court Limited | Households | 2004 |
| Harlson Timber Frame Ltd | Construction | 2018 |
| Harlstone Transport Limited | Transport & logistics | 1991 |
| Harmain Capital Ltd | Real estate | 2026 |
| Harman Contracting Ltd | Professional & scientific | 2014 |
| Harmby Properties Limited | Real estate | 1973 |
| Harmer Property Solutions Ltd | Real estate | 2015 |
| Harmonia Designs Ltd | Professional & scientific | 2026 |
| Harmonia Home Care Limited | Administrative & support | 2024 |
| Harmonic Edge Ltd | Professional & scientific | 2024 |
| Harmonise IT Consulting Ltd | Information & communication | 2013 |
| Harmont Investment Company Limited | Extraterritorial | 1963 |
| Harmony and Resonance Ltd | Professional & scientific | 2025 |
| Harmony Blinds of Leigh Ltd | Wholesale & retail | 2016 |
| Harmony Housing Management Ltd | Professional & scientific | 2019 |
| Harmony Property & Asset Ventures Ltd | Real estate | 2024 |
| Harmony Property Management and Services Limited | Real estate | 2024 |
| Harmony Retail Cloud Ltd | Wholesale & retail | 2025 |
| Harmony Robo GOV Ltd | Information & communication | 2026 |
| Harmonyhealth Limited | Public administration | 2026 |
| Harmonypeak Investments Ltd | Extraterritorial | 2025 |
| Harmonyz Ltd | Construction | 2018 |
| Harnbury Holdings Ltd | Hospitality | 1992 |
| Harnbury Ltd | Hospitality | 1978 |
| Harnoor Distributions Ltd | Wholesale & retail | 2017 |
| Harnpeak Global Trade Ltd | Wholesale & retail | 2026 |
| Harodin Ltd | Professional & scientific | 2026 |
| Harold P. Heywood & Co. Limited | Other services | 1997 |
| Haroon Phoneix Ltd | Wholesale & retail | 2025 |
| Haroon Rashid Ltd | Professional & scientific | 2022 |
| Haroon Saeed Ltd | Health & social care | 2012 |
| Haroon Visuals Ltd | Information & communication | 2020 |
| Haroun Photography Ltd | Professional & scientific | 2022 |
| Harp Construction Services Ltd | Professional & scientific | 2025 |
| Harp Heart Ltd | Hospitality | 2020 |
| Harper and Hunter Limited | Construction | 2016 |
| Harper Car Wash Ltd | Administrative & support | 2022 |
| Harper Craven Associates Limited | Education | 1989 |
| Harper Enterprises Ltd | Real estate | 2026 |
| Harper Law Ltd | Professional & scientific | 2021 |
| Harper Mill Management Company Limited | Households | 2005 |
| Harper Motors (Dukinfield) Limited | Transport & logistics | 1983 |
| Harper Oak Properties Ltd | Real estate | 2022 |
| Harperdale Limited | | 1984 |
| Harperfoldstables Limited | Agriculture & fishing | 2020 |
| Harpers Comedy Limited | Arts & recreation | 2015 |
| Harpers Hair Studios Ltd | Other services | 2017 |
| Harperstone Ltd | Wholesale & retail | 2024 |
| Harpreet Deals Ltd | Wholesale & retail | 2025 |
| Harpur's Plaice Limited | Hospitality | 2024 |
| Harpurhey Homes Ltd | Real estate | 2009 |
| Harpurhey Nails Ltd | Other services | 2026 |
| Harra Living Ltd | Hospitality | 2024 |
| Harriemore Limited | Professional & scientific | 2018 |
| Harrier Consulting Ltd | Professional & scientific | 2024 |
| Harriet and DEE Limited | Wholesale & retail | 1998 |
| Harriet Williams Ltd | Health & social care | 2015 |
| Harrington Company Management Ltd | Wholesale & retail | 2025 |
| Harrington Grounds Management Company Ltd | Households | 2022 |
| Harrington House Estates Limited | Construction | 2002 |
| Harrington Leigh Associates Ltd | Administrative & support | 2014 |
| Harrington Taylor Financial Consultants Ltd | Professional & scientific | 2019 |
| Harrington Wealth Limited | Professional & scientific | 2026 |
| Harrington&Co Property Ltd | Wholesale & retail | 2026 |
| Harris & Ross Limited | Health & social care | 2004 |
| Harris Advisory Legal Ltd | Professional & scientific | 2020 |
| Harris and Reeves Properties Ltd | Real estate | 2012 |
| Harris D Care Ltd | Health & social care | 2023 |
| Harris Electrical Services Ltd | Construction | 2018 |
| Harris Global Solutions Limited | Professional & scientific | 2016 |
| Harris Healthcare Ltd | Health & social care | 2018 |
| Harris Sltns Ltd | Information & communication | 2025 |
| Harris Street Management Company Limited | Real estate | 2022 |
| Harrison & SON Will Writing Service Ltd | Professional & scientific | 2025 |
| Harrison & Sons,Limited | Professional & scientific | 1920 |
| Harrison Advisory Ltd | Professional & scientific | 2026 |
| Harrison and Company (UK) Limited | Professional & scientific | 2009 |
| Harrison Architectural Drawings Limited | Professional & scientific | 2021 |
| Harrison Business Consultants Ltd | Professional & scientific | 2024 |
| Harrison Chambers Limited | Professional & scientific | 2025 |
| Harrison Design and Developments Ltd | Construction | 2023 |
| Harrison Housing Specialist Ltd | Construction | 2025 |
| Harrison Ince Design Partnership Limited | Professional & scientific | 2019 |
| Harrison Ince Group Limited | Financial services | 2017 |
| Harrison Ince Holdings Limited | Professional & scientific | 2012 |
| Harrison International Engineering Ltd | Professional & scientific | 2026 |
| Harrison James Property Ltd | Real estate | 2020 |
| Harrison Mccarthy (Bathroom & Plumbing Supplies) Limited | Wholesale & retail | 2009 |
| Harrison Microsystem Consultants Limited | Professional & scientific | 2012 |