| Heather House Development Ltd | Construction | 2013 |
| Heather House Rental Ltd | Extraterritorial | 2013 |
| Heather ST. Johns FC Limited | Arts & recreation | 2016 |
| Heavenly Studios Limited | Professional & scientific | 2025 |
| Hendon Waterside Energy Centre Management Company Limited | Households | 2020 |
| Hendon Waterside Residents’ Management Company Limited | Households | 2020 |
| Henshall Contracts Ltd | Construction | 2025 |
| Henstock Shooter Ltd | Extraterritorial | 2011 |
| Heritage Painting Services Ltd | Construction | 2022 |
| Heritage Park Block C (SW17 6BB) Ltd | Real estate | 2013 |
| HFI Training Limited | Education | 1999 |
| HGI Logistics Solutions Ltd | Transport & logistics | 2020 |
| HGV Expert Ltd | Transport & logistics | 2018 |
| HI Innovation Midlands Limited | Financial services | 2020 |
| Hideaway Projects Ltd | Construction | 2023 |
| High Street Quarter Energy Centre Management Company Limited | Households | 2020 |
| High Street Quarter Residents’ Management Company Limited | Households | 2020 |
| Highbury Equity Ltd | Real estate | 2024 |
| Higher Opportunities Limited | Professional & scientific | 2021 |
| Highhavenestate Limited | Real estate | 2024 |
| Highland Decorators (Midlands) Ltd | Construction | 2021 |
| Highmark Services Limited | Wholesale & retail | 1988 |
| Hiko Hounds Ltd | Other services | 2023 |
| Hiko Scented WAX Ltd | Wholesale & retail | 2023 |
| Hillstone Estates Ltd | Real estate | 2021 |
| Hive Composites Limited | Professional & scientific | 2019 |
| Hobby Hall Farm Ltd | Real estate | 2022 |
| Holcim Participations (UK) Limited | Financial services | 2004 |
| Holcim UK Cement Limited | Mining & quarrying | 2014 |
| Holcim UK Holdings 1 Limited | Financial services | 1922 |
| Holcim UK Holdings 2 Limited | Financial services | 2005 |
| Holcim UK Limited | Mining & quarrying | 1930 |
| Hollywood Aesthetics Ltd | Health & social care | 2017 |
| Home Delivery Express Ltd | Transport & logistics | 2020 |
| Homestead Day Nursery Ltd | Health & social care | 2013 |
| Honey Badger Pictures Ltd. | Arts & recreation | 2025 |
| HOO Hill Holdings Limited | Financial services | 2017 |
| Hope and Glorious Limited | Other services | 2019 |
| Hope Springs Village Ltd | Health & social care | 2018 |
| Horizon Health Consultancy Limited | Administrative & support | 2024 |
| Horizon Hobby Limited | Wholesale & retail | 2003 |
| Horizon M&E Limited | Construction | 2024 |
| House NO 3 Limited | Real estate | 2020 |
| House of Vintage Furnitures Ltd | Wholesale & retail | 2019 |
| HOUSE2HOME Property Enhancement Limited | Construction | 2020 |
| Hove Mindcare Limited | Public administration | 2025 |
| Howen Installations Ltd. | Professional & scientific | 2014 |
| HQS Holdings Limited | Financial services | 2020 |
| Hsds Properties Limited | Extraterritorial | 2025 |
| Hugglescote Grange (HG4) (Cadeby Homes) Manco Ltd | Households | 2025 |
| Hugglescote Vehicle Services Ltd | Wholesale & retail | 2024 |
| Hugopolo Enterprises Ltd | Real estate | 2024 |
| Huipil Ltd | Wholesale & retail | 2023 |
| Hunters Electrical Limited | Construction | 2008 |
| Hutchby & Collumbell Limited | Real estate | 1933 |
| HV Operational Services Ltd | Professional & scientific | 2022 |
| Hydro Utility Solutions (Midlands) Limited | Construction | 2019 |
| Hydro Utility Solutions Ltd | Professional & scientific | 2014 |
| Hydro-Dry Environmental Ltd | Administrative & support | 2025 |
| Hygge Socks Limited | Wholesale & retail | 2016 |
| Hypergalaxy Limited | Information & communication | 2011 |
| I Craft Carpentry Ltd | Manufacturing | 2025 |
| IAN Fardell Interiors Ltd | Construction | 2015 |
| Ibstock Kitchens JA Ltd | Manufacturing | 2016 |
| Ickenham Properties LLP | | 2026 |
| ICO Trading UK Ltd | Wholesale & retail | 2013 |
| Ics-Installations Ltd | Construction | 2021 |
| Idle Works Limited | Professional & scientific | 1956 |
| Ignite GAS (E.Midlands) Ltd | Other services | 2013 |
| Ijs-Risk-Co Ltd | Financial services | 2020 |
| IM Digital Studio Limited | Information & communication | 2025 |
| Impact Fire and Security Ltd | Administrative & support | 2019 |
| Imperium Electrical Services Ltd | Construction | 2017 |
| In-Vent Riser Cleaning Limited | Administrative & support | 2020 |
| Incubator Capital Partners Ltd | Financial services | 2013 |
| Inds Holdings Limited | Financial services | 2021 |
| Infield Ltd | Wholesale & retail | 2015 |
| Infinity Park Derby LLP | | 2014 |
| Infradigi Limited | Professional & scientific | 2019 |
| Infraready Ltd | Wholesale & retail | 2012 |
| Infused Resolutions Ltd | Administrative & support | 2023 |
| Ingley Holdings Ltd | Financial services | 2021 |
| Initialize Films Ltd | Information & communication | 2003 |
| Inky Threads Ltd | Manufacturing | 2024 |
| Inner Engineering Limited | Professional & scientific | 2019 |
| Innerstate Project Ltd | Wholesale & retail | 2021 |
| Innotech Digital & Display Limited | Manufacturing | 2013 |
| Innovation & Design Engineering Limited | Professional & scientific | 2004 |
| Insimbi Engagobiyo Ltd | Financial services | 2026 |
| Inspect-A-Drain (Midlands) Limited | Water & waste | 2017 |
| Inspire IFA Limited | Financial services | 2011 |
| Inspire Landscaping Group Limited | Administrative & support | 2024 |
| Instacoach in the Community CIC | Health & social care | 2023 |
| Instacoach UK Ltd | Health & social care | 2022 |
| Instruments Direct (Services) Limited | Wholesale & retail | 2004 |
| Integral Safety Ltd | Professional & scientific | 2020 |
| Integrated Control Utilities Limited | Construction | 2002 |
| Interiors by Law Ltd | Manufacturing | 2019 |
| Interlink Park Management Company Limited | Households | 1994 |
| International Rides Ltd. | Arts & recreation | 2017 |