| Humphrey and Scace Limited | Professional & scientific | 2010 |
| Humphrey Carpentry and Construction Ltd | Construction | 2026 |
| Humphreys Garage Ltd. | Administrative & support | 2014 |
| Hungrydown Farm Ltd | Agriculture & fishing | 2025 |
| Hunt Motor Company Ltd | Wholesale & retail | 2022 |
| Hunter & Brooks Limited | Hospitality | 2016 |
| Hurkle Limited | Manufacturing | 2024 |
| Hurlock Homes Limited | Wholesale & retail | 2005 |
| Hurstdale Apparel Company Ltd | Administrative & support | 2020 |
| Hutch Design Ltd | Professional & scientific | 2017 |
| Hutchings Developments Ltd | Construction | 2026 |
| Hutchings Wealth Consulting Ltd | Professional & scientific | 2026 |
| Hvcs Installations Limited | Construction | 2001 |
| Hvcs Spares Limited | Wholesale & retail | 2015 |
| HW Coffee Ltd | Hospitality | 2017 |
| HWB Investments Limited | Construction | 2015 |
| HWT Ventures Ltd | Professional & scientific | 2024 |
| HWY Films Limited | Information & communication | 2014 |
| HYD Ltd | Information & communication | 2009 |
| Hydrogen Dukebox Music Ltd | Information & communication | 1993 |
| Hyper Solutions Limited | Information & communication | 2008 |
| Hypermedia Technology Limited | Information & communication | 2014 |
| Hyphen Design Agency Limited | Professional & scientific | 2015 |
| HYS Properties Ltd | Real estate | 2020 |
| Hysterical Ltd | Professional & scientific | 2025 |
| HYY Holdings Ltd | Professional & scientific | 2026 |
| I a Plumbing Ltd | Construction | 2020 |
| I Blame Rupert Limited | Information & communication | 2017 |
| I E Consultancy Limited | Professional & scientific | 2008 |
| I-Link Trading Limited | Wholesale & retail | 2026 |
| I.M Maintenance Services Limited | Construction | 2012 |
| Ibbc Limited | Real estate | 2020 |
| Ibbett Mosely Limited | Extraterritorial | 1984 |
| Ibbett Mosely Surveyors Limited Liability Partnership | | 2008 |
| IC Equestrian Limited | Arts & recreation | 2020 |
| Icfa Ltd | Education | 2022 |
| ICM Support LLP | | 2021 |
| Icon Health & Safety Ltd | Professional & scientific | 2007 |
| Iconic Landscapes Ltd | Administrative & support | 2019 |
| IDE Hill Community Shop CIC | Wholesale & retail | 2012 |
| IDE Hill Freehold Management Company Limited | Households | 2007 |
| IDE Hill Hall Assets Limited | Real estate | 2013 |
| IDE Hill Hall RTM Company Limited | Administrative & support | 2017 |
| IDE Hill Park Leasehold Management Company Limited | Households | 2007 |
| IDE Hill Park Management Company Limited | Households | 2007 |
| Ideal Mats Limited | Other services | 2011 |
| Ideas & Impact Ltd | Professional & scientific | 2019 |
| Identifiers Limited | Professional & scientific | 1991 |
| IDG Foundation CIC | Other services | 2022 |
| Idwala Research Limited | Professional & scientific | 2020 |
| IEI3 Limited | Professional & scientific | 2023 |
| Iford Close Freehold Management Company Limited | Households | 2022 |
| Ightham Plumbing and Heating Ltd | Construction | 2025 |
| Ignition Consultancy Ltd | Administrative & support | 2021 |
| IJ Hospitality Group Ltd | Hospitality | 2026 |
| IJJ Consultancy Ltd | Real estate | 2016 |
| Ikin VT Consultancy Group Limited | Financial services | 2023 |
| Imagine Better Together CIC | Professional & scientific | 2025 |
| Imaging Solutions Limited | Health & social care | 2008 |
| IMC (UK) Learning Ltd | Information & communication | 2006 |
| Imensas Ltd | Information & communication | 2021 |
| Imerolia Marina Developments Limited | Construction | 2026 |
| IMG VFX Limited | Information & communication | 2012 |
| Immersive and Inclusive Audio CIC | Information & communication | 2021 |
| Immortal Capital Ltd | Financial services | 2015 |
| Immunogy Limited | Education | 2023 |
| Impact AJG Ltd | Wholesale & retail | 2019 |
| Impactagri (UK) Ltd | Financial services | 2015 |
| Imperial Bitumen Limited | Extraterritorial | 2025 |
| Imperial Fintech Limited | Financial services | 2023 |
| Improvement Analytics Ltd | Professional & scientific | 2017 |
| Inca Projection Plastering Limited | Construction | 2012 |
| Inchcut Ltd | Other services | 2021 |
| Incredible GXP Services Limited | Professional & scientific | 2025 |
| Independent Hotel Management Consultancy Limited | Professional & scientific | 2026 |
| Indiana Montana Ltd | Professional & scientific | 2019 |
| Indo-Brit Investments Limited | Real estate | 2025 |
| Indulge Mini ME Ltd | Wholesale & retail | 2011 |
| Indus Consulting Services Limited | Professional & scientific | 2014 |
| Indust-Rail Ltd | Wholesale & retail | 2019 |
| Indust-Solution Services Ltd | Wholesale & retail | 2020 |
| Infeel Creative Limited | Information & communication | 2017 |
| Infine Consultants Ltd | Professional & scientific | 2008 |
| Infineedle Limited | Wholesale & retail | 2020 |
| Infinite Percent Limited | Wholesale & retail | 2018 |
| Infinity Circuits Ltd | Other services | 2011 |
| Influx Commercial Services Ltd | Construction | 2023 |
| Ingarden Limited | Wholesale & retail | 2005 |
| Ingrid Limited | Administrative & support | 1997 |
| Injury QED Limited | Administrative & support | 2006 |
| INK Cosmetics Ltd | Wholesale & retail | 2021 |
| Inkpots Creative Limited | Education | 2025 |
| Inline Fulfilment Ltd | Extraterritorial | 2014 |
| Inline International Ltd | Transport & logistics | 2008 |
| Inovocaddy Ltd | Information & communication | 2018 |
| Inscope Management Services Limited | Construction | 2001 |
| Inside Ecology Ltd | Administrative & support | 2012 |
| Inside OUT Sevenoaks Ltd | Construction | 2016 |
| INSIDE22 Ltd | Information & communication | 2026 |
| Insightbox Limited | Information & communication | 2022 |