| Holdens Enterprise Ltd | Wholesale & retail | 2021 |
| Holdonamo Ltd | Financial services | 2021 |
| Holiday Cottage Housekeepers Ltd | Administrative & support | 2020 |
| Holiday Inspirations Limited | Administrative & support | 2012 |
| Holly Avenue Management Limited | Real estate | 2021 |
| Hollycote Limited | Professional & scientific | 2024 |
| Home Farm Welford Ltd | Construction | 2023 |
| Home of the Sofa Limited | Wholesale & retail | 2010 |
| Homerent Investco Ltd | Real estate | 2026 |
| Homestyle Design Limited | Professional & scientific | 2017 |
| Honey BEE Meadow Ltd | Agriculture & fishing | 2020 |
| Honeyfly Limited | Hospitality | 2021 |
| Hongyun Collection Limited | Information & communication | 2018 |
| Honour ME Limited | Education | 2023 |
| Hooray’S Gelato Kitchen Ltd | Manufacturing | 2020 |
| Hopwood Advisory Ltd | Professional & scientific | 2026 |
| Horizon Geology Ltd | Mining & quarrying | 2023 |
| Horizondata Services Ltd | Information & communication | 2023 |
| HOS OSS Ltd | Wholesale & retail | 2023 |
| Hoskin Hobbs Limited | Administrative & support | 2020 |
| Hospitality First Management Limited | Administrative & support | 2016 |
| Hothouse Designs Limited | Wholesale & retail | 2011 |
| House of Bard Properties Ltd | Hospitality | 2025 |
| House of Spells Limited | Wholesale & retail | 2019 |
| Housey Mchouseface Ltd | Real estate | 2024 |
| Howard Road Management (2012) Limited | Administrative & support | 2013 |
| Howlett Machine Tool Services Limited | Manufacturing | 2018 |
| How’S IT Hanging Ltd | Manufacturing | 2025 |
| HPH Holidays Limited | Hospitality | 2017 |
| HPH Roslyn Holidays Limited | Hospitality | 2023 |
| HS Living Ltd | Hospitality | 2026 |
| Hudson's Trading Spaces Ltd | Wholesale & retail | 2023 |
| Hughes Legal Limited | Professional & scientific | 2015 |
| Hughes Trading Ltd | Hospitality | 2023 |
| HUM Flowerpots Ltd | Wholesale & retail | 2025 |
| Human Eyes Limited | Information & communication | 2022 |
| Humanity Healthcare Ltd | Health & social care | 2019 |
| Hunscote Consulting Limited | Professional & scientific | 2001 |
| Hunsley Construction Limited | Construction | 2022 |
| Hunter Mechanical Ltd | Construction | 2019 |
| Hurt for Friends Limited | Wholesale & retail | 2025 |
| Hush Cinema Ltd | Real estate | 2012 |
| HW Group (Midlands) Limited | Construction | 2023 |
| HWD Solutions Limited | Construction | 2015 |
| Hycool Global Limited | Wholesale & retail | 2011 |
| Hydropro Cleaning Limited | Administrative & support | 2022 |
| Hyperflight Limited | Wholesale & retail | 2011 |
| Hyperion Care Developments (Didcot) Limited | Construction | 2018 |
| Hyperion Group Holdings Ltd | Financial services | 2021 |
| Hysort Ltd | Professional & scientific | 2018 |
| I Compari Ltd | Hospitality | 2022 |
| I T Allison Limited | Agriculture & fishing | 2011 |
| I'M Sexy and I MOW IT! Ltd | Administrative & support | 2023 |
| I-Invest Management Ltd | Professional & scientific | 2018 |
| I4S Consulting Ltd | Professional & scientific | 2023 |
| IAN Downing Consulting Limited | Professional & scientific | 2024 |
| Icarus Reach Limited | Information & communication | 2025 |
| Icom Estate Solutions Ltd | Construction | 2007 |
| Icomed Limited | Manufacturing | 2001 |
| ID Rendering Specialist Ltd | Construction | 2025 |
| Idea Catalyst Partners LLP | | 2011 |
| Ideal Home Supplies (Moreton-In-Marsh) Limited | Wholesale & retail | 1957 |
| Identity Assurance Systems Limited | Information & communication | 2010 |
| Igesía Limited | Professional & scientific | 2022 |
| IL Sorelle Limited | Other services | 2019 |
| Ilfracombe Park Ltd | Hospitality | 2025 |
| Illumit Limited | Information & communication | 2002 |
| Ilmington Homes Limited | Construction | 2024 |
| ILT Consultant Services Limited | Professional & scientific | 2023 |
| IM Freight Forwarding Limited | Transport & logistics | 2014 |
| Imagefile Limited | Information & communication | 1991 |
| IMM Lionhandyman Company Ltd | Administrative & support | 2021 |
| Imogen Cork Ltd | Other services | 2020 |
| Impact Commercial Vehicle Repairs Limited | Wholesale & retail | 2005 |
| Imperatyv UK Ltd | Manufacturing | 2024 |
| Imutual Worldwide Limited | Information & communication | 2010 |
| IN for a Penne Ltd | Hospitality | 2022 |
| Inca Health Consultancy Limited | Professional & scientific | 2025 |
| IND Solutions Limited | Wholesale & retail | 2004 |
| Independent Academic Researchers Ltd | Information & communication | 2021 |
| Independent Penguin Limited | Information & communication | 2024 |
| Independent Remarketing Solutions Limited | Extraterritorial | 2015 |
| Indigo Cloud Limited | Information & communication | 2012 |
| Indigo Contract Management Limited | Construction | 2017 |
| Industrial Air Compressors Limited | Other services | 2025 |
| Ingeneus Ltd | Administrative & support | 2016 |
| Ingram House Limited | Construction | 2025 |
| Inicio Solutions Ltd | Professional & scientific | 2022 |
| Inidimman Consultants Limited | Information & communication | 2014 |
| Inneo Solutions Limited | Administrative & support | 2007 |
| Inovape (Web) Ltd | Wholesale & retail | 2020 |
| Inside Outside Sport Limited | Other services | 2019 |
| Inside Voice Communications Ltd | Professional & scientific | 2023 |
| Insidious Studios Ltd | Information & communication | 2023 |
| Insight Property Management Solutions Limited | Real estate | 2017 |
| Insight Trans Logistics Ltd | Transport & logistics | 2004 |
| INSIGHTS2OUTPUTS Ltd | Professional & scientific | 2025 |
| Inspiriem Technologies Limited | Information & communication | 2008 |
| Intelligent Storm Solutions Limited | Information & communication | 2018 |
| Intent Ecommerce Limited | Information & communication | 2019 |