| Habibti Jaunts Limited | Administrative & support | 2025 |
| Hadley House RTM Company Limited | Households | 2026 |
| Hadstone International Energy Limited | Professional & scientific | 2016 |
| Haghri Co Limited | Health & social care | 2015 |
| Hail Mary Games Ltd | Wholesale & retail | 2024 |
| Hailsham 1963 Limited | Extraterritorial | 2015 |
| Hailsham Accountants Ltd | Professional & scientific | 2013 |
| Hailsham Active CIC | Health & social care | 2017 |
| Hailsham and District BID Ltd | Other services | 2021 |
| Hailsham Chiropractic Clinic Limited | Health & social care | 2012 |
| Hailsham Frontiers Charitable Trust | Other services | 2006 |
| Hailsham Innovations Ltd | Manufacturing | 2013 |
| Hailsham Motor Works Limited | Wholesale & retail | 2026 |
| Hailsham Parish Mission Trust | Other services | 2018 |
| Hailsham Scaffolding Limited | Construction | 2012 |
| Hailsham Structures Limited | Construction | 1985 |
| Hainault Gentle Dental Care Limited | Health & social care | 2011 |
| Halal Shop Limited | Wholesale & retail | 2010 |
| Halcyon Academy Ltd | Information & communication | 2026 |
| Halcyon Enterprises Ltd | Information & communication | 2021 |
| Halcyon Retreat UK Ltd | Administrative & support | 2021 |
| Hall S P Limited | Wholesale & retail | 2017 |
| Hallmark Cinemas LLP | | 2009 |
| HAM Road Developments Ltd | Real estate | 2023 |
| Hamax Holdings Limited | Real estate | 2024 |
| Hambles Carpet and Upholstery Care Ltd | Administrative & support | 2025 |
| Hamilton Quay Management Company Limited | Households | 2004 |
| Hamlin House LLP | | 2012 |
| Hammer Head UK Limited | Construction | 2002 |
| Hammerhead Electrical Services Ltd | Construction | 2016 |
| Hampden View Limited | Households | 2001 |
| Hampton Estates Limited | Real estate | 2016 |
| Handforth Heritage Consulting Limited | Professional & scientific | 2021 |
| Handingwell Ltd | Professional & scientific | 2010 |
| Handyman's Corner (Brixton) Limited | Wholesale & retail | 1977 |
| Hangin Tree Frog Limited | Construction | 2014 |
| Hankham Organics Ltd | Wholesale & retail | 2004 |
| Hanki Properties Ltd | Real estate | 2025 |
| Hannah Baker Limited | Health & social care | 2018 |
| Hannah Flower Ltd | Professional & scientific | 2003 |
| HAP Services Ltd | Construction | 2007 |
| Hapanco Limited | Other services | 2012 |
| Happy Mango Smile Limited | Professional & scientific | 2023 |
| Happy Scissors Ltd | Information & communication | 2008 |
| Harbour Designs Limited | Construction | 2018 |
| Harbour Imaging Direct Limited | Health & social care | 2022 |
| Harbour Lights a (Eastbourne) Management Company Limited | Households | 1990 |
| Harbour Multiple Services Ltd | Construction | 2023 |
| Harbourside Gymnastics Academy Ltd | Arts & recreation | 2019 |
| Harder & Mehl Ltd | Health & social care | 2018 |
| Hardwick House Committee Limited | Households | 2005 |
| Hardwicke House Freehold Limited | Households | 2009 |
| Harecount Ltd | Professional & scientific | 2012 |
| Harecroft Stores Limited | Wholesale & retail | 2014 |
| Hargrave Ltd | Construction | 2025 |
| Hargreaves Business Park Limited | Real estate | 2005 |
| Harhicaj Ltd | Hospitality | 2025 |
| Harle Paris Ltd | Manufacturing | 2023 |
| Harlestone Homes Limited | Extraterritorial | 2012 |
| Harley's Tavern Ltd | Hospitality | 2024 |
| Harmony in Motion Ltd | Education | 2024 |
| Harold Surveys Ltd | Professional & scientific | 2017 |
| Harpenden Dental Practice Ltd | Health & social care | 2016 |
| Harper Hair Co Ltd | Other services | 2018 |
| Harrigan Cove Limited | Hospitality | 2017 |
| Harringman Holdings Ltd | Financial services | 2024 |
| Harris Court Property Management Company Limited | Households | 2009 |
| Harris Electrical Engineering Ltd | Professional & scientific | 2013 |
| Harrison Agency Ltd | Professional & scientific | 2005 |
| Harrison Close Limited | Administrative & support | 2024 |
| Harrison Heating Sussex Limited | Construction | 2024 |
| Harrison Incorporated Ltd | Wholesale & retail | 2004 |
| Harrlie Plumbing Ltd | Construction | 2026 |
| Harrow Weald Dental Practice Ltd | Health & social care | 2022 |
| Harrybreeds Ltd | Wholesale & retail | 2025 |
| Harshen Surgical Care Ltd | Health & social care | 2022 |
| Hart & Co. Plumbing and Heating Ltd | Construction | 2021 |
| Hart Reade LLP | | 2021 |
| Hartington Freeholders Limited | Households | 1998 |
| Hartington Mansions Management Co. Limited | Households | 1972 |
| Hartland Hoodies Ltd | Wholesale & retail | 2020 |
| Hartley Court (Bexhill) Limited | Households | 1990 |
| Harvey & MAY Limited | Administrative & support | 2005 |
| Harvey Property Ventures Limited | Real estate | 2023 |
| Hastings Live Music Ltd | Hospitality | 2020 |
| Hauge Lytton Limited | Health & social care | 2010 |
| Haulaway (Skips) Limited | Water & waste | 2017 |
| Haulaway Limited | Transport & logistics | 1991 |
| Havana Atmosphere Limited | Extraterritorial | 2023 |
| Havana Court Freehold Limited | Real estate | 2004 |
| Havard and Co Ltd | Wholesale & retail | 2011 |
| Havelock Estates Limited | Real estate | 1994 |
| Haven Court (Beckenham) Management Limited | Households | 1982 |
| Haven Garage Limited | Wholesale & retail | 2006 |
| Haven Installations Limited | Other services | 2012 |
| Haven Kitchen and Bar Limited | Hospitality | 2023 |
| Havens Medical Lettings Ltd | Real estate | 2018 |
| Hawk Healthcare Ltd | Health & social care | 2023 |
| Hawkins Commercial Investments Ltd | Real estate | 2021 |
| Hawkins DUO Limited | Construction | 2016 |