| Halmatic Ltd | Information & communication | 2012 |
| Halo & HUE Designs Ltd | Wholesale & retail | 2024 |
| Hamblin Care Support Service Limited | Public administration | 2020 |
| Hammett Performance Group Ltd | Professional & scientific | 2024 |
| Hampshire Pantry Ltd | Hospitality | 2024 |
| Hampton Marine Limited | Real estate | 1970 |
| Hampton Safety Ltd | Other services | 2019 |
| Hampton Steel and Wire Limited | Extraterritorial | 1952 |
| Hampton Steel Limited | Manufacturing | 1991 |
| Handcraft Holding Company Limited | Professional & scientific | 2019 |
| Handcraft Manufacturing Limited | Wholesale & retail | 2004 |
| Hands Free IT Limited | Information & communication | 2005 |
| Handyman Stefan Ltd | Construction | 2020 |
| Hangar .41 Ltd | Professional & scientific | 2024 |
| Hani Trading Ltd | Wholesale & retail | 2015 |
| Hannah's Hair Parlour Ltd | Other services | 2020 |
| Hansel Logistics Ltd | Transport & logistics | 2016 |
| Happy Friday Ltd | Real estate | 2026 |
| Happydayz Nursery (Northants) Ltd | Health & social care | 2023 |
| Harborough Garden Machinery Ltd | Other services | 2018 |
| Harbur Holdings Ltd | Financial services | 2025 |
| Hardtwell Limited | Extraterritorial | 2024 |
| Hardwick & Heath Ltd | Wholesale & retail | 2023 |
| Hardwick (Wellingborough) Limited | Real estate | 2024 |
| Harkstate Limited | Real estate | 2022 |
| Harlestone Consulting Ltd | Professional & scientific | 2023 |
| Harmonious Duck Limited | Information & communication | 2012 |
| Harmony Spa by Marta Ltd | Health & social care | 2025 |
| Harrison Transport & Investments Ltd | Transport & logistics | 2026 |
| Harrisonhub Socials Ltd | Professional & scientific | 2024 |
| Harrium Consulting Ltd | Administrative & support | 2017 |
| Harrowden Buccleuch Limited | Real estate | 2025 |
| Harrowden Farms Group Limited | Agriculture & fishing | 2014 |
| Harrowden Farms Limited | Agriculture & fishing | 1964 |
| Harshini Ltd | Wholesale & retail | 2023 |
| Harshini Property Ltd | Real estate | 2025 |
| Harvest Services Limited | Real estate | 2025 |
| Harvester Software Limited | Information & communication | 2016 |
| Hatschek Luxury Bathrooms Limited | Construction | 2015 |
| Hatton Academies Trust | Education | 2012 |
| Hatton Park Gardens Management Limited | Households | 2021 |
| Hatton School Limited | Hospitality | 2011 |
| Hatton Square Wealth Planning Ltd | Financial services | 2025 |
| Haus of WOW Events Ltd | Administrative & support | 2026 |
| Hava Core Properties Ltd | Real estate | 2023 |
| Haven Circle Companionship Ltd | Health & social care | 2026 |
| Haven Distributors Limited | Wholesale & retail | 2025 |
| Hawkins Engineering Ltd | Manufacturing | 2009 |
| Hawkwell Limited | Financial services | 2026 |
| Hawthorn & Grove Farm Ltd | Agriculture & fishing | 2023 |
| Hayburner Ltd | Information & communication | 2022 |
| Hayche Ltd | Wholesale & retail | 2025 |
| Hayesdale Fire Protection Ltd | Public administration | 2025 |
| Hayyan Closes Ltd | Professional & scientific | 2025 |
| Hazel Tree Country Boarding Kennels LLP | | 2017 |
| Hazmak Ltd | Health & social care | 2023 |
| HBP Property Rentals Ltd | Real estate | 2025 |
| Hbsz Limited | Real estate | 2022 |
| HCF Surveying Ltd | Professional & scientific | 2025 |
| HCK Civils Limited | Construction | 2016 |
| HCK Lettings Limited | Real estate | 2019 |
| HCL Technic Limited | Construction | 2024 |
| HD Sign and Digital Ltd | Manufacturing | 2020 |
| HDJ Infotech Ltd | Information & communication | 2025 |
| HDJ Realty Ltd | Real estate | 2022 |
| Head to TOE Trading Limited | Wholesale & retail | 2021 |
| Headson Ceramics Limited | Construction | 2010 |
| Headway East Northants Limited | Health & social care | 1999 |
| Health Pro Ltd | Health & social care | 2022 |
| Healthpro Staffing Ltd | Administrative & support | 2024 |
| Hearing to the T Ltd | Health & social care | 2025 |
| Heartbeat a CIC | Arts & recreation | 2023 |
| Hearts Care Services UK Ltd | Other services | 2017 |
| Heat Well Ltd | Construction | 2025 |
| Heathfield Park View Limited | Professional & scientific | 2016 |
| Heatsavers Energy Solutions Ltd | Construction | 2020 |
| Hebrigging Ltd | Construction | 2025 |
| Heidi Harper Limited | Manufacturing | 2018 |
| Heidi's Boutique Limited | Wholesale & retail | 2015 |
| Held in Spite Ltd | Wholesale & retail | 2026 |
| Helmdon Blackpits Power Limited | Energy | 2014 |
| Help and Safety at Work Limited | Public administration | 2003 |
| Helping Hand Projects & Consulting Limited | Professional & scientific | 2014 |
| Helping Hands Recruitment Agency Ltd | Wholesale & retail | 2017 |
| HEM BBQ Ltd | Hospitality | 2026 |
| Hemphill Fabrications Ltd | Construction | 2022 |
| Hendrickson United Kingdom Ltd | Manufacturing | 1985 |
| Henry Property Management Ltd | Real estate | 2023 |
| Henry's Property Services Limited | Households | 2021 |
| Henry's Rentals Limited | Households | 2025 |
| Hercrownuk Ltd | Other services | 2019 |
| Hermes Memini Ltd | Construction | 2026 |
| Hernik Building Services Ltd | Construction | 2024 |
| Hernik Sales and Lettings Ltd | Real estate | 2016 |
| Hero JI Beds Ltd | Hospitality | 2025 |
| Hero JI Ltd | Hospitality | 2024 |
| Herodontics Ltd | Health & social care | 2025 |
| Hevalyns Limited | Professional & scientific | 2017 |
| Hewitt Trading Ltd | Wholesale & retail | 2026 |
| Hews Construction Limited | Administrative & support | 2024 |