| Holtamerch Limited | Hospitality | 1979 |
| Holy Mackerel 1066 Ltd | Wholesale & retail | 2023 |
| Honestdaily Ltd | Manufacturing | 2026 |
| HOP Gardens Properties Limited | Real estate | 2025 |
| HOP Gardens Residents Limited | Households | 2025 |
| Hope Creative Ltd | Information & communication | 2008 |
| Horntye Park Management Company | Arts & recreation | 2001 |
| Horseshoe Place Management Limited | Households | 2022 |
| Hosiery-Direct-Uk Limited | Wholesale & retail | 2008 |
| Hotheads Limited | Information & communication | 2002 |
| House Sussex Limited | Construction | 2026 |
| Hovhannes. Ltd | Wholesale & retail | 2024 |
| Howard House RTM Company Ltd | Households | 2008 |
| HP Building Company Limited | Construction | 2015 |
| HRS Property Holdings Limited | Real estate | 2016 |
| HSC Clinic Limited | Health & social care | 2006 |
| Hubb Holdings Limited | Financial services | 2011 |
| Hubble Aquacare Construction Limited | Construction | 2024 |
| Hubble Aquacare Limited | Agriculture & fishing | 2022 |
| Humanbeing Beinghuman CIC | Education | 2025 |
| Humanova Apps Ltd | Information & communication | 2026 |
| Hurst Developments (Mauhart) Limited | Construction | 2013 |
| Hurstways 1066 Ltd | Construction | 2014 |
| HW International Ltd | Wholesale & retail | 2017 |
| Hybrid Developments (South East) Ltd | Construction | 2022 |
| Hydea 21 Ltd | Hospitality | 2018 |
| Hydroschool Limited | Arts & recreation | 2015 |
| Hype Solutions Limited | Hospitality | 2021 |
| I Love Falafel Ltd | Hospitality | 2024 |
| IA Finance Limited | Financial services | 2017 |
| IAN Hyder & Company Ltd. | Real estate | 2002 |
| IAN Strang Limited | Agriculture & fishing | 2012 |
| IB Osteopathy Limited | Health & social care | 2023 |
| IBC - in Perpetuity | Health & social care | 2020 |
| Ibss Brands Limited | Wholesale & retail | 2024 |
| IC Resources Ltd | Professional & scientific | 2019 |
| Icare Recruitment Ltd | Administrative & support | 2021 |
| Icollard Biomedical Ltd | Professional & scientific | 2025 |
| Idea Generation Ltd | Professional & scientific | 2023 |
| Ideal Mini Market Hastings Ltd | Wholesale & retail | 2026 |
| Ideal Mini Market Ltd | Wholesale & retail | 2016 |
| Igloo Property Investments LLP | | 2009 |
| Ignis Safety Solutions Limited | Public administration | 2024 |
| Ijgm Limited | Information & communication | 2025 |
| Imaani Ltd | Construction | 2018 |
| IMC Contracting Ltd | Professional & scientific | 2026 |
| Immersive Album Experience Limited | Information & communication | 2021 |
| Immersive Album Limited | Information & communication | 2021 |
| IN 2 Play C.I.C. | Education | 2006 |
| IN the Spirit of Innovation Limited | Professional & scientific | 2026 |
| Inbetween Space Limited | Information & communication | 2004 |
| Incident Ready Consulting Ltd | Professional & scientific | 2020 |
| Independant Toiletries Limited | Manufacturing | 2013 |
| Indox Ltd | Information & communication | 2026 |
| Inevotech Ltd | Professional & scientific | 2019 |
| Inmercity UK Ltd | Administrative & support | 2025 |
| Inn the Doghouse Again Ltd | Hospitality | 2024 |
| Innovate Leisure Ltd | Hospitality | 2019 |
| Innovation Incorporated Ltd | Wholesale & retail | 2023 |
| Inqontrol Limited | Construction | 2011 |
| Inside OUT Digital Marketing Limited | Information & communication | 2010 |
| Inspire to Speak Ltd | Health & social care | 2020 |
| Instant Keys Autolocksmith Ltd | Wholesale & retail | 2024 |
| Integral MAN CIC | Health & social care | 2025 |
| Integral Wellness Limited | Health & social care | 2022 |
| Interactive Hive Limited | Information & communication | 2006 |
| Interesting Ideas Limited | Construction | 2012 |
| Invigilating Service for Best Independent Schools Limited | Education | 2025 |
| Ioana B Ltd | Transport & logistics | 2017 |
| Iproperty Investments Limited | Construction | 2016 |
| Iproperty Solutions Limited | Real estate | 2012 |
| Ipsum Logistics Ltd | Transport & logistics | 2025 |
| Iresidential Ltd | Hospitality | 2019 |
| Ironworks UK Limited | Manufacturing | 1992 |
| Irth Designs Ltd | Wholesale & retail | 2012 |
| Island Design Limited | Professional & scientific | 2019 |
| Isobel Anderson Services Ltd | Information & communication | 2024 |
| Isolinear Ltd | Information & communication | 2025 |
| Italiana Restaurant (Bexhill) Ltd | Hospitality | 2009 |
| Itandwebsupport Ltd | Professional & scientific | 2016 |
| Itca Limited | Professional & scientific | 2020 |
| ITF Detectives Limited | Administrative & support | 2014 |
| Izzy K Productions Ltd | Arts & recreation | 2025 |
| J Andersen Limited | Wholesale & retail | 2003 |
| J Coryton Ltd | Professional & scientific | 2026 |
| J D Mills Ltd | Construction | 2005 |
| J Elliott Electrical Ltd | Construction | 2021 |
| J Elliott Inspection / Testing & Fire Alarm Safety Ltd | Professional & scientific | 2025 |
| J N Food & Wine Ltd | Wholesale & retail | 2011 |
| J N Toys Limited | Wholesale & retail | 2001 |
| J&J Emporium Ltd | Wholesale & retail | 2023 |
| J.Hayden(Carpets)Limited | Wholesale & retail | 1970 |
| J.Ro SCO Services Limited | Construction | 2024 |
| J.S.Steel Services Ltd | Administrative & support | 2001 |
| Jack Black Pest Control Services Ltd | Administrative & support | 2022 |
| Jack High Bowls Limited | Wholesale & retail | 2012 |
| Jaeban Limited | Administrative & support | 2008 |
| Jake Robbins Vintage Engineering Limited | Manufacturing | 2012 |
| Jalcopa Ltd | Professional & scientific | 2014 |
| JAM Construction Services Ltd | Construction | 2025 |