| Hertfordshire Loan Management Limited | Financial services | 2019 |
| Hetnet Ltd | Professional & scientific | 2018 |
| Hexcha Limited | Health & social care | 2015 |
| HFI Consulting Services Limited | Information & communication | 2022 |
| HG Footworks Ltd | Health & social care | 2014 |
| HGV Local Ltd | Administrative & support | 2026 |
| HI Speed Food Fleet Ltd | Hospitality | 2024 |
| Highbury Investments Limited | Real estate | 2018 |
| Highgrove Windows (UK) Ltd | Construction | 2015 |
| Hightec Vision Ltd | Information & communication | 2006 |
| Hilydproperties Ltd | Real estate | 2017 |
| Hirt Limited | Administrative & support | 2011 |
| Holland Valley Ltd | Construction | 2025 |
| Holman Services Ltd | Professional & scientific | 2025 |
| Holographic Innovations Limited | Manufacturing | 2009 |
| Holographic Security Innovations Limited | Manufacturing | 2007 |
| Homeclean Hampshire Ltd | Administrative & support | 2017 |
| Homestay Properties Ltd | Real estate | 2020 |
| Honey N Coconut Ltd | Health & social care | 2025 |
| Honeywell Health Care Ltd | Health & social care | 2020 |
| Hope House FM Ltd | Professional & scientific | 2019 |
| Hopes and Dreams Ltd | Extraterritorial | 2008 |
| Horizon Imaging Ltd | Information & communication | 2007 |
| HORIZON38 Ltd | Information & communication | 2025 |
| Horn Select Developments Ltd | Real estate | 2022 |
| Hornchurch Square Farnborough Residents Management Company Limited | Households | 2013 |
| Houghton Lewis Group Ltd. | Construction | 2015 |
| House Mortgage Solutions Ltd | Financial services | 2017 |
| House With Blue Shutters Ltd | Real estate | 2017 |
| Houston COX Central Limited | Construction | 2004 |
| Houston COX Fire Door Solutions Limited | Professional & scientific | 2026 |
| Houston COX Limited | Professional & scientific | 2001 |
| Howe Building Group Ltd | Construction | 2021 |
| HPM Consultancy Services Ltd | Professional & scientific | 2023 |
| HPM Steam Engineering Limited | Wholesale & retail | 2010 |
| HR Radio Ltd | Information & communication | 2026 |
| HT Hair Limited | Other services | 2025 |
| Hubfiiit Limited | Arts & recreation | 2020 |
| Hudsons Investments Limited | Hospitality | 2025 |
| Hugo Shaw Properties Limited | Real estate | 2018 |
| Huntercombe Consultants Ltd | Professional & scientific | 2011 |
| Hurst Warne Commercial Property Management Ltd | Real estate | 2017 |
| Huxleys Mercedes Specialist Limited | Wholesale & retail | 2015 |
| HW Autos Limited | Wholesale & retail | 2021 |
| Hybridge Limited | Administrative & support | 2011 |
| Hyperwifi Ltd | Information & communication | 2024 |
| I AM Denim Ltd | Wholesale & retail | 2015 |
| I Griffin Ltd | Energy | 2009 |
| I I 10 Consultancy Limited | Information & communication | 2004 |
| I Want a Mortgage Ltd | Financial services | 2022 |
| I-Financial Consultants Ltd | Information & communication | 2021 |
| I-Procure Technology Limited | Information & communication | 2017 |
| Iain Mclachlan Consultancy Limited | Information & communication | 2024 |
| Icaria LLP | | 2016 |
| Icdc Ltd | Real estate | 2026 |
| Icme Property Ltd | Real estate | 2021 |
| Iconnect Communications UK Ltd | Wholesale & retail | 2009 |
| IFS - Debt LP | | 2023 |
| Iki-Force Ltd | Information & communication | 2023 |
| Imac Systems Limited | Manufacturing | 1979 |
| Imana Consulting Ltd | Financial services | 2017 |
| Immermyth Limited | Information & communication | 2017 |
| Implemented Imagination Limited | Information & communication | 2014 |
| IN 2 HR Ltd | Administrative & support | 2005 |
| IN the BAG Promotions Limited | Professional & scientific | 2015 |
| IN Tune Virtual Services Limited | Professional & scientific | 2021 |
| Inclusive Transformations Ltd | Professional & scientific | 2008 |
| Independent Projects Workshop Ltd | Information & communication | 2025 |
| Indev Real Estate Limited | Professional & scientific | 2022 |
| Index Companies Holdings Limited | Administrative & support | 2010 |
| Index Ebusiness Limited | Information & communication | 2010 |
| Index Inventories Limited | Real estate | 2017 |
| Indigo Labs Limited | Information & communication | 2014 |
| Infigo Media Ltd | Information & communication | 2008 |
| Influencer Trustmark Limited | Information & communication | 2024 |
| Infologica Consulting Limited | Information & communication | 2008 |
| Infrastructure Consent Services Limited | Professional & scientific | 2023 |
| Infrastructure Industries Limited | Professional & scientific | 2025 |
| Ingenium Consulting Services Limited | Professional & scientific | 2017 |
| Ingwe Development Limited | Information & communication | 2007 |
| Initiate Wealth Management Limited | Financial services | 2012 |
| Innerfit Limited | Arts & recreation | 2016 |
| Innoteq Solutions Ltd | Professional & scientific | 2019 |
| Innovate Home Improvements Ltd | Construction | 2024 |
| Innoways Limited | Professional & scientific | 2008 |
| Inspire Gymnastics in Schools Ltd | Education | 2022 |
| Inspired Facilities Management Group Limited | Construction | 2023 |
| Inspired Technologies UK Ltd | Professional & scientific | 2009 |
| Inspired Transitions Ltd | Professional & scientific | 2015 |
| Install IT Ltd | Administrative & support | 2021 |
| Intelligent Accountancy Services Limited | Professional & scientific | 2011 |
| Intelligent Data Networks Limited | Information & communication | 2019 |
| Intent Works Limited | Construction | 2012 |
| Interbuilding Projects Limited | Construction | 2001 |
| Interior Decisions Limited | Wholesale & retail | 1989 |
| Internet Shed Investments Limited | Real estate | 2018 |
| Intouch Tech Ltd | Information & communication | 2012 |
| Investment Assessment Limited | Professional & scientific | 2015 |
| Invio Industries Ltd | Manufacturing | 2025 |
| Iora Acquisition Enterprises Limited | Information & communication | 2018 |