| HAIRDAYS1 Ltd | Other services | 2024 |
| Halcyon House Creative Ltd | Professional & scientific | 2025 |
| Hamblin Developments Ltd | Wholesale & retail | 2017 |
| Hamels Wellness Stamford Ltd | Health & social care | 2022 |
| Hampton Business Park Management Company Limited | Real estate | 2011 |
| Hampton Lakeview Limited | Construction | 2016 |
| Handsome Devils Barber Club Ltd | Other services | 2025 |
| HAP Limited | Professional & scientific | 2001 |
| Hare and Hounds (Greatford) Ltd | Hospitality | 2018 |
| Harkie Global Ltd | Wholesale & retail | 2019 |
| Harp Business Centre Limited | Real estate | 1980 |
| Harr Fleet Ltd | Information & communication | 2023 |
| Harrison & Dunn Ltd | Wholesale & retail | 2011 |
| Harrison Landscapes Limited | Administrative & support | 2020 |
| Haven Rentals Limited | Real estate | 2022 |
| Hawkspeed Ltd | Transport & logistics | 2022 |
| Hawksworth Carpenters Ltd | Construction | 2014 |
| Haynes Horticulture Limited | Administrative & support | 2020 |
| HBL Global Partners Limited | Administrative & support | 2025 |
| Headline Support Ltd | Administrative & support | 2026 |
| Healthcare Location Limited | Real estate | 2006 |
| Healthreach Limited | Hospitality | 2014 |
| Healthy Hearing Limited | Health & social care | 2022 |
| Heart and Horizon Coaching Limited | Education | 2025 |
| Heavy Pencil Limited | Professional & scientific | 2012 |
| Hector and Pearl Ltd | Manufacturing | 2019 |
| Hegarty Therapy Ltd | Health & social care | 2018 |
| Helen Blythe Consulting Limited | Professional & scientific | 2018 |
| Hello Mind Ltd | Health & social care | 2020 |
| Hemex LLP | | 2007 |
| Hendry White Ltd | Real estate | 2022 |
| Herdale Digital Consulting Limited | Professional & scientific | 2016 |
| Heritage Horticulture Cambridgeshire Ltd | Administrative & support | 2025 |
| Herts Electrical Services Limited | Construction | 2011 |
| HFB MJK Properties Ltd | Real estate | 2025 |
| Hi-Spec Precision Engineering Limited | Manufacturing | 2011 |
| Hightrees Homes Ltd | Real estate | 2024 |
| Hill-Fort Tree Care Ltd | Administrative & support | 2015 |
| Hinch Plant and Contractors Limited | Construction | 1996 |
| Hindmarch Holdings Limited | Financial services | 2023 |
| Historical Roofing Services Ltd | Extraterritorial | 2023 |
| Hive Leisure (Callow Hall) Limited | Administrative & support | 2018 |
| Hive Leisure Limited | Administrative & support | 2018 |
| Hoarding Disorders UK (East) CIC | Other services | 2025 |
| Hofn Trading Limited | Manufacturing | 2025 |
| Holdings Group Limited | Financial services | 2026 |
| Holly&Lil the Collar Makers Ltd | Manufacturing | 2012 |
| Holmach Limited | Wholesale & retail | 1974 |
| Home Farm Management (Ketton) Company Limited | Households | 2024 |
| Homes by Katie Cardew Ltd | Professional & scientific | 2022 |
| Hometime 2020 Ltd | Real estate | 2018 |
| Homewise Property Limited | Real estate | 2017 |
| Honest Content Ltd | Professional & scientific | 2019 |
| Hoppi Dorri Ltd | Real estate | 2018 |
| Horton's Emporium Ltd | Arts & recreation | 2018 |
| Houghton Web Studio Ltd | Information & communication | 2025 |
| Hounds on the Hill Limited | Other services | 2025 |
| Hourhero Ltd | Information & communication | 2021 |
| House of Skin & Beauty Ltd | Other services | 2025 |
| HRL Consulting Limited | Professional & scientific | 2017 |
| HRO Property Limited | Real estate | 2024 |
| HTM Security Solutions Ltd | Construction | 2023 |
| Human Workings Ltd | Information & communication | 2025 |
| Hunters Interiors (Stamford) Limited | Professional & scientific | 2003 |
| Huntmore Limited | Administrative & support | 2000 |
| Huxley Automotive Limited | Wholesale & retail | 2021 |
| Hyde Design and Build Limited | Construction | 2024 |
| Hydrava Heating & Plumbing Limited | Construction | 2021 |
| Hydroscape-Group Ltd | Professional & scientific | 2025 |
| I & R EC Ltd | Professional & scientific | 2003 |
| I AM Robyn Limited | Professional & scientific | 2018 |
| I Mortgage Group Ltd. | Financial services | 2008 |
| I-Compli Solutions Limited | Information & communication | 2022 |
| I-Tg International Services Ltd | Wholesale & retail | 2019 |
| IAN Halsall Decorators Limited | Construction | 2021 |
| IAN Mcnaught Limited | Wholesale & retail | 2019 |
| IAW Property Limited | Real estate | 2012 |
| IBC Supplies Limited | Wholesale & retail | 2010 |
| IC Assets Ltd | Real estate | 2025 |
| Icgregory Limited | Real estate | 2007 |
| Iconz Experience Ltd. | Arts & recreation | 2015 |
| IDS Driving School Ltd | Education | 2025 |
| IF Audio Studio Ltd | Wholesale & retail | 2026 |
| Ii-Vi Laser Enterprise Ltd | Professional & scientific | 2013 |
| Iibm Ltd | Administrative & support | 2013 |
| Ikon Campers Ltd | Manufacturing | 2025 |
| IM Hospitality Ltd | Hospitality | 2020 |
| Imagine Plus UK Ltd | Other services | 2024 |
| Imassets Ltd | Financial services | 2023 |
| Impact Resilience Limited | Professional & scientific | 2022 |
| Impeller Ventures Ltd | Professional & scientific | 2016 |
| Imprezaco Ltd | Financial services | 2012 |
| INDF1 (Sandridge) LLP | | 2023 |
| Indigo 24 Ltd | Information & communication | 2021 |
| Inexa Talent Solutions Ltd | Administrative & support | 2019 |
| Infinite Coaching Limited | Education | 2007 |
| Infinite Raven Coaching and Consultancy Ltd | Professional & scientific | 2023 |
| Infinity Developments (Cambs) Ltd | Construction | 2025 |
| Inncona Limited | Professional & scientific | 2018 |
| Inner Bloom Sound Temple Limited | Wholesale & retail | 2020 |