| Highfield Court Residents Association Limited | Real estate | 1976 |
| Highgate Capital Limited | Professional & scientific | 2020 |
| Highgrain Limited | Real estate | 1987 |
| Highlands Freehold Limited | Households | 1997 |
| Highlands Management Limited | Households | 1986 |
| Highlands Orchard Residents Association Ltd | Households | 1986 |
| Highline Autos Ltd | Wholesale & retail | 2017 |
| Highoak Properties Limited | Other services | 2011 |
| Highplus Limited | Financial services | 1997 |
| Highstone Advisory Ltd | Professional & scientific | 2018 |
| Highstone Clarity Ltd | Professional & scientific | 2020 |
| Highstone Limited | Extraterritorial | 2014 |
| Highview (New Barnet) Limited | Professional & scientific | 2005 |
| Highview Advisory Limited | Professional & scientific | 2021 |
| Higive Ltd | Other services | 2011 |
| Hilaf Limited | Health & social care | 2018 |
| Hill Farm Avenue Limited | Administrative & support | 2012 |
| Hill Farm High Street Limited | Administrative & support | 2013 |
| Hill Farm Projects Limited | Real estate | 2023 |
| Hill Farm Studios and Workshops Limited | Extraterritorial | 2021 |
| Hill Farm Studios Limited | Extraterritorial | 2021 |
| Hill House Research Limited | Professional & scientific | 2014 |
| Hill Top Carehome Limited | Health & social care | 2026 |
| Hillbillyz Ltd | Wholesale & retail | 2024 |
| Hillclay Holdings Limited | Real estate | 2022 |
| Hillcrest Catering Co. Limited | Hospitality | 1970 |
| Hillcroft Brand and Marketing Limited | Administrative & support | 2017 |
| Hily House Property Limited | Households | 1964 |
| Himalayan Express Ltd | Wholesale & retail | 2014 |
| Hinton Advisers Ltd | Professional & scientific | 2025 |
| Hircombe Holdings Ltd | Professional & scientific | 2021 |
| Hire Genius Limited | Information & communication | 2020 |
| Hire Sprint Ltd | Administrative & support | 2025 |
| Hire-In Ltd | Administrative & support | 2019 |
| Hirecruit Limited | Administrative & support | 2023 |
| Hissa Group Ltd | Real estate | 2016 |
| Hitaki Holdings Ltd | Real estate | 2025 |
| Hitchings Partnership Limited | Real estate | 2009 |
| Hittite Limited | Extraterritorial | 2021 |
| Hixon and Hound Limited | Other services | 2025 |
| HJ Design Solutions Limited | Professional & scientific | 2021 |
| HJK Technology Ltd | Information & communication | 2020 |
| HJW Services Ltd | Arts & recreation | 2022 |
| HK Architects Ltd | Professional & scientific | 2015 |
| HK Properties (London) Limited | Professional & scientific | 2015 |
| HL Postal Ltd | Wholesale & retail | 2021 |
| HLH General Builders Ltd | Construction | 2004 |
| HLH Maintenance Ltd | Construction | 2016 |
| HLP Investments Limited | Administrative & support | 2013 |
| HNR Security Services Limited | Administrative & support | 2025 |
| HNV Drylining Ltd | Construction | 2016 |
| HOA Beauty Bromley Ltd | Other services | 2023 |
| HOA London Academy Ltd | Other services | 2023 |
| Hobday Property Management Limited | Real estate | 2002 |
| Hokandara Limited | Administrative & support | 2015 |
| Hokey Cokey Limited | Extraterritorial | 2013 |
| Hola City Ltd | Hospitality | 2021 |
| Hola Guacamole Ltd | Hospitality | 2017 |
| Hola Guacamole Wembley Limited | Hospitality | 2018 |
| Holborn Energy Derivatives Ltd | Financial services | 2025 |
| Holborn Studios Limited | Other services | 1992 |
| Holborn Trading Ltd. | Financial services | 2016 |
| Holiday Air Ltd. | Administrative & support | 2006 |
| Holistech Souls Ltd | Information & communication | 2022 |
| Holistics Collective Limited | Financial services | 2025 |
| Holistics Design Limited | Professional & scientific | 2026 |
| Holly Cullen Casting Limited | Arts & recreation | 2019 |
| Holly Farm Management Ltd | Real estate | 2026 |
| Hollyfields Farm Fresh Eggs Ltd | Wholesale & retail | 2021 |
| Hollywood Court (Elstree) Flats Management Co. Limited | Households | 1974 |
| Holm Oak Developments Ltd | Real estate | 2024 |
| Holm Oak Investments Limited | Real estate | 2021 |
| Holmbrook Estates Limited | Real estate | 2019 |
| Holmes Procurement Limited | Professional & scientific | 2013 |
| Holmes Professional Services Limited | Professional & scientific | 2014 |
| Holmewood Hall Ltd | Administrative & support | 2018 |
| Holt Hideaway Ltd | Real estate | 2022 |
| Holtram Tlpi Ltd | Financial services | 2020 |
| Holy Corn Limited | Manufacturing | 2026 |
| Home City Ltd | Information & communication | 2007 |
| Home Glazing Improvements Limited | Construction | 2001 |
| Home Improvements by Modplan Ltd | Construction | 2012 |
| Home Investment Ltd | Real estate | 2016 |
| Home Rehab Therapists Ltd | Health & social care | 2019 |
| Homebeck Limited | Real estate | 1985 |
| Homebuilders Ltd | Construction | 2019 |
| Homeland Capital Limited | Administrative & support | 2022 |
| Homely Estates Limited | Real estate | 2020 |
| Homely Holdings Ltd | Administrative & support | 2022 |
| Homelyfe Property Services Ltd | Construction | 2025 |
| Homemap Ltd | Construction | 2026 |
| HOMEPHYSIO247 Ltd | Health & social care | 2019 |
| Homes Enterprises Ltd | Wholesale & retail | 2022 |
| Homes for YOU Properties Limited | Real estate | 2021 |
| Homesmart Properties Limited | Real estate | 2020 |
| Homesolutions 4U Limited | Administrative & support | 2024 |
| Homevision Services Ltd | Administrative & support | 2024 |
| Homewood Properties (Herts) Limited | Real estate | 1998 |
| Honeycolm Homes Ltd | Real estate | 2024 |
| Honeymaster Limited | Hospitality | 1994 |