| Hexanets Ltd | Arts & recreation | 2025 |
| HG Heating & Plumbing Ltd | Construction | 2022 |
| HGV 4 YOU Ltd. | Transport & logistics | 2018 |
| HI Summer Limited | Hospitality | 2021 |
| Hi-Rise Lifting Solutions Ltd | Construction | 2018 |
| Hickmire Limited | Manufacturing | 2006 |
| High CI Ltd | Manufacturing | 2023 |
| High Hopes Limited | Health & social care | 2019 |
| High Street Okra Ltd | Hospitality | 2025 |
| High Street Properties (Wellingborough) Limited | Construction | 2016 |
| High View Consultants Limited | Professional & scientific | 2013 |
| Highfield Community Centre | Arts & recreation | 2023 |
| Highway & City Construction Limited | Construction | 2013 |
| Hiles International Consultants Ltd | Professional & scientific | 2017 |
| Hillfarm Fire Barrier Specialists Ltd | Public administration | 2025 |
| Hilton UK Properties Ltd | Real estate | 2017 |
| Himesh Panchal Limited | Health & social care | 2011 |
| Hincus Ltd | Transport & logistics | 2011 |
| Hinwick Estate Management Ltd | Hospitality | 2026 |
| Hireful Ltd | Information & communication | 1999 |
| HIS Grace Family Home Ltd | Hospitality | 2023 |
| HIT the Ground Sprinting Limited | Information & communication | 2006 |
| HJG Estates Ltd | Real estate | 2023 |
| HK Panchal Properties Ltd | Real estate | 2017 |
| HKM Logistics Ltd | Transport & logistics | 2025 |
| HLM Enterprises Limited | Energy | 2022 |
| HME Finance Ltd | Financial services | 2017 |
| HMG Estates Ltd | Real estate | 2014 |
| HMJ Transportation Limited | Transport & logistics | 2024 |
| HMO Heating Solutions UK Ltd | Construction | 2019 |
| HMW Freelance Limited | Arts & recreation | 2025 |
| HO Transport Ltd | Transport & logistics | 2016 |
| Hodges Properties Limited | Real estate | 2023 |
| Hody Security Services Ltd | Administrative & support | 2022 |
| Hoji Go-Go Ltd | Manufacturing | 2020 |
| Holcot Property Ltd | Real estate | 2018 |
| Holeigh Homes Ltd | Real estate | 2024 |
| Hollyclove Property Management Limited | Real estate | 2006 |
| Hollywood & Co Limited | Professional & scientific | 2013 |
| Home Air Conditioning & Electrical Ltd | Construction | 2024 |
| Home-Start Wellingborough & District | Health & social care | 2006 |
| Homecare Solutions for YOU Limited | Administrative & support | 2022 |
| Hone's Homes Ltd. | Real estate | 2024 |
| Honeds Cleaning Services Ltd | Administrative & support | 2026 |
| Honest Care Services Ltd | Public administration | 2019 |
| Honest Juice Ltd | Manufacturing | 2024 |
| Honey Badger Joinery Ltd | Manufacturing | 2025 |
| Honey Coaching Ltd | Education | 2023 |
| Horizon Facility Services Ltd | Administrative & support | 2020 |
| Hornett Limited | Administrative & support | 2025 |
| Hornigold Services Ltd | Transport & logistics | 2024 |
| Horses for Good Ltd | Agriculture & fishing | 2021 |
| Hot Bunz N Grill Limited | Hospitality | 2025 |
| House One Services Ltd | Households | 2018 |
| Housetop Contractor Ltd | Construction | 2018 |
| Housewives Choice (Rushden) Limited | Wholesale & retail | 2003 |
| Howper 756 Limited | Financial services | 2013 |
| HPA (Groundworks) Limited | Construction | 2016 |
| HPJ Management Ltd | Professional & scientific | 2024 |
| HQ 4 U Solutions Ltd | Transport & logistics | 2019 |
| Hruve Ltd | Professional & scientific | 2018 |
| HS Trade Ltd | Wholesale & retail | 2025 |
| HSH Estates Ltd | Real estate | 2019 |
| HSH Northants Ltd | Wholesale & retail | 2024 |
| HSM P&H Limited | Construction | 2024 |
| Hub Property (Northants) Ltd | Other services | 2023 |
| Hubscope Ltd | Information & communication | 2022 |
| Hudy Limited | Transport & logistics | 2020 |
| Hulatt & Barnes Limited | Wholesale & retail | 2002 |
| Hunnings Consultancy Limited | Professional & scientific | 2014 |
| Hutch Management Services Limited | Professional & scientific | 2020 |
| HV SPV 1 Limited | Professional & scientific | 2016 |
| HV SPV 2 Limited | Professional & scientific | 2016 |
| Hwata Ltd | Transport & logistics | 2026 |
| Hyam Capital Ltd | Construction | 2012 |
| Hydrographicswarehouse Ltd | Wholesale & retail | 2021 |
| Hylec - APL Limited | Wholesale & retail | 1980 |
| Hylec Components Limited | Wholesale & retail | 2015 |
| Hylec Enclosures Limited | Wholesale & retail | 2012 |
| Hylec Properties Limited | Real estate | 2015 |
| Hypar Tank Panels Limited | Extraterritorial | 1984 |
| Hyphen Estates Limited | Real estate | 2025 |
| I SRB Ltd | Construction | 2020 |
| I&I International Transport Limited | Transport & logistics | 2025 |
| I&K Property Investment Ltd | Real estate | 2023 |
| I&T Logistics Ltd | Wholesale & retail | 2025 |
| I-Floor Ltd | Construction | 2024 |
| I.T Blend Limited | Information & communication | 2018 |
| Iacob Construction Limited | Other services | 2018 |
| Iafll Limited | Professional & scientific | 2020 |
| IAN Jones Plumbing & Heating Ltd | Construction | 2013 |
| IAN ROY Taxi's Limited | Other services | 2005 |
| Ibes Security Services Limited | Wholesale & retail | 2022 |
| ICLEAN4U Property Management Services Ltd | Administrative & support | 2025 |
| Ideas in Hand Ltd | Extraterritorial | 2017 |
| Ideate Automotive Ltd | Professional & scientific | 2021 |
| Idolise Media Limited | Information & communication | 2022 |
| Idren Contracts Ltd | Wholesale & retail | 2020 |
| Idrissi & O’Driscoll Holdings Ltd | Other services | 2025 |
| Idrissi Holdings Ltd | Hospitality | 2023 |