| HI5 Foods Limited | Hospitality | 2025 |
| Hiff Limited | Real estate | 2024 |
| High Achievers Academy Limited | Education | 2021 |
| High Impact Global Limited | Professional & scientific | 2019 |
| Highfive Solutions Limited | Administrative & support | 2024 |
| Hilati Catering Ltd | Hospitality | 2022 |
| Hills Bridge Rail and Construction Ltd | Construction | 2022 |
| Hills Car Body Repairs Ltd | Wholesale & retail | 2023 |
| Hillton Cat Taxi Ltd | Transport & logistics | 2026 |
| Hipsu Properties Limited | Real estate | 2024 |
| Hive Learn Group Ltd | Education | 2024 |
| HM Legal Limited | Professional & scientific | 2024 |
| HMP Property Management Ltd | Financial services | 2023 |
| Holidaynest Ltd | Administrative & support | 2025 |
| Hollyoak Property Services Limited | Construction | 1998 |
| Home Decisions Limited | Other services | 2015 |
| Home Inspirations (UK) Limited | Wholesale & retail | 2013 |
| Homeease Property Management Ltd | Construction | 2025 |
| Homes 365 Ltd | Real estate | 2018 |
| Homes and Services Limited | Real estate | 2023 |
| Homespire Ltd | Wholesale & retail | 2023 |
| Hook Service Ltd | Construction | 2024 |
| Hope N Home Limited | Health & social care | 2025 |
| Hope of Glory Limited | Health & social care | 2012 |
| Hopeful Horizons Living Ltd | Health & social care | 2025 |
| Hopper Transport Services Ltd | Transport & logistics | 2023 |
| Horizon Recruitment Ltd | Administrative & support | 2025 |
| Horley Homes Limited | Construction | 2019 |
| Hornchurch Builders Limited | Wholesale & retail | 1975 |
| Hornchurch Logistics Ltd | Administrative & support | 2024 |
| Hornchurch Patch Testing Clinic Ltd | Health & social care | 2026 |
| Hot Bargains Ltd | Wholesale & retail | 2015 |
| Hotelhubs Property Limited | Hospitality | 2024 |
| House of Bookkeepers Ltd | Professional & scientific | 2025 |
| House of K Limited | Manufacturing | 2023 |
| House of Lovable Ltd | Administrative & support | 2023 |
| House of Padel Ltd | Wholesale & retail | 2025 |
| House of VAZ Limited | Wholesale & retail | 2026 |
| Hridoye Amar Bangladesh Ltd | Other services | 2023 |
| HRM Security Solutions Limited | Administrative & support | 2014 |
| Hs.Daniel Limited | Wholesale & retail | 2023 |
| HSK Automotive Ltd | Wholesale & retail | 2024 |
| HSM College Ltd | Education | 2023 |
| HT G Ltd | Hospitality | 2025 |
| HTS Food Limited | Hospitality | 2026 |
| HUDS10 Ltd | Other services | 2021 |
| Humaira's Army Limited | Information & communication | 2025 |
| Human Talent Services Ltd | Administrative & support | 2013 |
| Humble Living Estates Ltd | Professional & scientific | 2026 |
| Hummer Transport Limited | Transport & logistics | 2025 |
| Hungry DOT Ltd | Hospitality | 2020 |
| Huntesman Ltd | Real estate | 2024 |
| Hunza Co Ltd | Wholesale & retail | 2023 |
| Hutton Hall Events Essex Limited | Administrative & support | 2012 |
| Huxley Lloyd Limited | Information & communication | 2021 |
| Hyryde Ltd | Transport & logistics | 2018 |
| I AM Prosperous CIC | Construction | 2022 |
| I M Billionaire Ltd | Wholesale & retail | 2025 |
| I S H Consultancy Ltd | Professional & scientific | 2022 |
| I&I Services Limited | Construction | 2021 |
| IB Beauty Limited | Other services | 2026 |
| IB POWER1 Ltd | Construction | 2019 |
| IBI Homes Ltd | Real estate | 2023 |
| Ibib Investment Ltd | Financial services | 2018 |
| Icars London Limited | Wholesale & retail | 2022 |
| Icknield Capital Management Ltd | Manufacturing | 2014 |
| ICOM2 Food & Wine Ltd | Wholesale & retail | 2013 |
| Iconic Moves Limited | Real estate | 2020 |
| ICS Terminals (UK) Limited | Administrative & support | 1972 |
| ID Cleanings Limited | Administrative & support | 2025 |
| ID Property Group Limited | Manufacturing | 2022 |
| Idea Pro Ltd | Wholesale & retail | 2024 |
| Ideal International Limited | Construction | 2015 |
| Ifeoma Ventures Limited | Transport & logistics | 2025 |
| IG Quickfix Ltd | Administrative & support | 2016 |
| Igotdaice Limited | Wholesale & retail | 2026 |
| IH Pharma Ltd | Wholesale & retail | 2022 |
| Ijaz Group Ltd | Wholesale & retail | 2023 |
| IJS Holdings Group Ltd | Financial services | 2024 |
| Ikhoa Ventures Ltd | Professional & scientific | 2025 |
| Ikra Property Ltd | Real estate | 2017 |
| Ilirida Cafè Ltd | Hospitality | 2026 |
| Image on Group Limited | Wholesale & retail | 2018 |
| Imark Agency Ltd | Health & social care | 2022 |
| Imbers Management Services Ltd | Wholesale & retail | 2019 |
| Imdavidtalbert Consulting Ltd | Professional & scientific | 2022 |
| IMM Group Limited | Construction | 2026 |
| Impact Builders Ltd | Construction | 2026 |
| Inaaya Trade International Ltd | Wholesale & retail | 2021 |
| Inaya Creations Ltd | Wholesale & retail | 2025 |
| Indyfrt Limited | Transport & logistics | 2010 |
| Indyses Ltd | Health & social care | 2014 |
| Inet Capex Limited | Real estate | 2020 |
| Inet Group Limited | Information & communication | 2015 |
| Inet One Limited | Financial services | 2022 |
| Infinetymart Ltd | Wholesale & retail | 2024 |
| Infusion Glow Ltd | Other services | 2023 |
| Ingall Flooring Ltd | Construction | 2009 |
| Ingrid & Co Construction Ltd | Construction | 2025 |
| Innomotors Limited | Wholesale & retail | 2025 |