| Heritage Envelopes Limited | Manufacturing | 1986 |
| Heritage Tradesmen Ltd | Construction | 2019 |
| Herons Care and Support Limited | Health & social care | 2025 |
| Highfly Ventures Ltd. | Professional & scientific | 2015 |
| Highland Haze Limited | Wholesale & retail | 2025 |
| Highly Marelli UK Limited | Manufacturing | 2020 |
| Hilmar Limited | Real estate | 2003 |
| HJR Contractors Limited | Professional & scientific | 2023 |
| Hobbies and Handcrafts CIC | Hospitality | 2024 |
| Hoggett Automotive Ltd | Wholesale & retail | 2025 |
| Holmes and SON Property Limited | Real estate | 2025 |
| Home & Gift (UK) Limited | Wholesale & retail | 2005 |
| Home Management Group (Property Management) Limited | Real estate | 2018 |
| Home Management Group Limited | Real estate | 2016 |
| Home Trends (NE) Ltd | Wholesale & retail | 2021 |
| Home Trends Trading Ltd | Wholesale & retail | 2015 |
| Homes for YOU NE Ltd | Real estate | 2022 |
| Homestyle UK Roofing & Building Ltd | Construction | 2018 |
| Hoola Fashion Ltd | Wholesale & retail | 2025 |
| Horizon Training Associates Ltd | Administrative & support | 2016 |
| Horsley Enhanced Homes Ltd | Real estate | 2024 |
| Horvath Group Ltd | Professional & scientific | 2022 |
| Hot Bites Limited | Hospitality | 2013 |
| House of Destiny Ministries | Other services | 2007 |
| Howay Inn Limited | Administrative & support | 2018 |
| HSF Training Limited | Education | 2006 |
| HT Shaw Logistics Ltd | Transport & logistics | 2025 |
| Hughes Pumps Limited | Manufacturing | 1985 |
| Humble Warrior Yoga Ltd | Arts & recreation | 2024 |
| Humes LLC Ltd | Financial services | 2026 |
| Hunt Property Development Limited | Households | 2024 |
| Hurricane Shutters and Doors Limited | Manufacturing | 2020 |
| Hutchinson Logistics Ltd | Transport & logistics | 2025 |
| Hutchy's Bar Limited | Hospitality | 2023 |
| I J Cook Limited | Hospitality | 2003 |
| I Shoot Media Ltd | Arts & recreation | 2017 |
| I&Vm Ltd | Real estate | 2022 |
| Ibis Logistics Limited | Transport & logistics | 2019 |
| Icarus Courier Group Limited | Transport & logistics | 2024 |
| Ideas Education Ltd | Education | 2009 |
| IFC African, Latin American and Caribbean Fund, LP | | 2010 |
| IFC Catalyst Fund (Japan), LP | | 2013 |
| IFC Catalyst Fund (UK), LP | | 2012 |
| IFC Catalyst Fund, LP | | 2012 |
| IFC Financial Institutions Growth Fund, LP | | 2015 |
| IFC Middle East and North Africa Fund, LP | | 2015 |
| IFC Russian Bank Capitalization Fund LP | | 2012 |
| IHL Property Limited | Real estate | 2021 |
| IJH Professional Services Ltd. | Professional & scientific | 2021 |
| ILA Investment Group Ltd | Real estate | 2023 |
| Immersive Sound Studios Limited | Information & communication | 2025 |
| Impress Properties Ltd | Real estate | 2011 |
| Impressions NE Limited | Other services | 2016 |
| In-Hindsight Ltd | Information & communication | 2023 |
| Incharge EV Limited | Manufacturing | 2024 |
| Indices AI Limited | Information & communication | 2025 |
| Indie & Ivory Limited | Manufacturing | 2026 |
| Indigoseo Ltd | Professional & scientific | 2025 |
| Induction Pipe Bending UK Limited | Manufacturing | 2005 |
| Industrial Maintenance Solutions (NE) Ltd | Wholesale & retail | 2014 |
| Ingleford Scaffolding Limited | Construction | 2010 |
| Inicio People Limited | Professional & scientific | 2023 |
| Inkfinite Printing Limited | Manufacturing | 2024 |
| Intergalactic Shredquarters Ltd | Wholesale & retail | 2022 |
| International Initiative for Impact Evaluation 3IE | | 2021 |
| International Inspection Services Limited | Mining & quarrying | 2018 |
| Internet Association | | 2018 |
| Iotech Systems Limited | Information & communication | 2017 |
| Ipoc Limited | Wholesale & retail | 2024 |
| Ippm Limited | Wholesale & retail | 2025 |
| Irwin & Associates Limited | Professional & scientific | 2015 |
| Isabella Holdings Limited | Other services | 2016 |
| ISO Plumb Plumbing and Heating Limited | Construction | 2023 |
| Istanblue Barbers Ltd | Other services | 2019 |
| IT Supplies Ltd | Information & communication | 2021 |
| It'Z Print & Design (NE) Limited | Other services | 2009 |
| Italanglo Ltd | Real estate | 2013 |
| Italian Furnishing Ltd | Wholesale & retail | 2016 |
| Itec Management Consultants Limited | Professional & scientific | 2000 |
| J & J Property Maintenance & Services Ltd | Construction | 2019 |
| J & M Pet Beds Ltd | Administrative & support | 2010 |
| J & N Property Services Ltd | Real estate | 2021 |
| J Baddams Barbering Limited | Other services | 2025 |
| J Brennan Plumbing and Heating Ltd | Construction | 2017 |
| J E Parker Electrical Ltd | Construction | 2020 |
| J Ferry Management Limited | Construction | 2010 |
| J M B (NE) Limited | Arts & recreation | 2014 |
| J M Barham Limited | Information & communication | 2023 |
| J P Construction NE Ltd | Construction | 2025 |
| J Robinson Associates Ltd | Professional & scientific | 2007 |
| J T Communications Limited | Construction | 2016 |
| J Waring Finance and Consulting Ltd | Professional & scientific | 2024 |
| J&B Groundworks NE Limited | Construction | 2023 |
| J&F Johnson Holdings Limited | Financial services | 2023 |
| J&G Bodyworks Ltd | Wholesale & retail | 2025 |
| J. Dinning (Lumley) Limited | Wholesale & retail | 2012 |
| J.A.S. Print Limited | Manufacturing | 1981 |
| J.B. Graham (Print & Design) Limited | | 1981 |
| J.C. Atkinson and SON Limited | Other services | 1966 |
| J.D.R. Management Limited | Professional & scientific | 1998 |