| Halo Worldwide Limited | Financial services | 2019 |
| Halogen Events Ltd | Arts & recreation | 2019 |
| Hamilton Business Technologies Limited | Information & communication | 2025 |
| Hamilton Management (London) Limited | Administrative & support | 2024 |
| Hamilton Rentals Limited | Information & communication | 1972 |
| Hampden Crescent 1-8 RTM Company Limited | Households | 2020 |
| Hampshire Divecrew Training 2012 Limited | Education | 2012 |
| Hamptons Paving Ltd | Construction | 2025 |
| Hands & EYE Support Ltd | Professional & scientific | 2025 |
| Hands on Money Ltd | Administrative & support | 2025 |
| Handsel Consultancy Limited | Professional & scientific | 2004 |
| Handy Property Solutions Limited | Construction | 2024 |
| Hankmalik Consulting Limited | Information & communication | 2021 |
| Hannah Grace Ltd | Professional & scientific | 2018 |
| Happy Homes Property Lettings Limited | Real estate | 2025 |
| HAQ Medical Limited | Health & social care | 2026 |
| Haque Medical Consultants Ltd | Health & social care | 2018 |
| Hari Dharm Infotech Limited | Information & communication | 2022 |
| Harkiss Properties Limited | Real estate | 2021 |
| Harkiss Solutions Limited | Information & communication | 2022 |
| Harleyx Ltd | Arts & recreation | 2020 |
| Harling Hair Ltd | Other services | 2013 |
| Harmer Editorial Ltd | Professional & scientific | 2013 |
| Harmony Veterinary Care Ltd | Professional & scientific | 2023 |
| Harnell Plus Limited | Information & communication | 2009 |
| Harp Engineering Limited | Manufacturing | 2004 |
| Harp Farm Limited | Agriculture & fishing | 1962 |
| Harper Care Group Ltd | Health & social care | 2025 |
| Harpspring Designs Limited | Professional & scientific | 1986 |
| Harrington & Branch Electrical Ltd | Construction | 2025 |
| Harris of London Ltd | Manufacturing | 2023 |
| Harrison Cars Ltd | Wholesale & retail | 2025 |
| Harrisphere Group Limited | Professional & scientific | 2025 |
| Harrnet Limited | Information & communication | 2014 |
| Harrow Teacher Training Limited | Education | 2022 |
| Harry Chapman Consultancy Ltd | Professional & scientific | 2024 |
| Hartland Road Holdings Ltd | Real estate | 2024 |
| Hartleys Limited | Professional & scientific | 1992 |
| Harwell Associates Limited | Professional & scientific | 2019 |
| HAT and Home Limited | Real estate | 2020 |
| Havelock Arms Management Limited | Real estate | 2013 |
| Haven Build Ltd | Construction | 2023 |
| Haven Point Solutions Limited | Wholesale & retail | 2024 |
| Havisham Homes Limited | Real estate | 2013 |
| Hawk Air (2025) Limited | Transport & logistics | 2022 |
| Hawkcliff Property Ltd | Real estate | 2009 |
| Hawker Aircraft Limited | Professional & scientific | 2005 |
| Hawker Hunter Aviation Limited | Public administration | 2000 |
| Hawkins Design Limited | Professional & scientific | 2024 |
| Hawthorns (Flackwell Heath) Management Co. Limited(The) | Households | 1982 |
| Haya Candles Limited | Wholesale & retail | 2023 |
| Haya Global Investments Limited | Financial services | 2024 |
| Haya Investments Ltd | Real estate | 2018 |
| Hayes Beaumont Arbitration Ltd | Professional & scientific | 2025 |
| Hayes Grove Management Company Limited | Households | 2024 |
| Hayley Anselm Counselling Limited | Health & social care | 2023 |
| Hayrizon Ltd | Administrative & support | 2017 |
| Hazura Sports Limited | Wholesale & retail | 2002 |
| HBT Homes Ltd | Construction | 2024 |
| HC Block & Estate Management Ltd | Real estate | 2021 |
| HC Block Commercial Ltd | Households | 2025 |
| HC Block Compliance Services Ltd | Real estate | 2025 |
| HC Block Legal Services Ltd | Real estate | 2025 |
| HC Property NET (Wokingham) Ltd | Real estate | 2020 |
| HCC Keystone Holdings Limited | Real estate | 2026 |
| HD Installations Ltd. | Construction | 2018 |
| HDS Civil Engineering Ltd | Construction | 2019 |
| HDS Groundwork Ltd | Construction | 2018 |
| Head for Heights Berkshire Ltd | Administrative & support | 2025 |
| Headcount Worldwide Field Marketing Limited | Administrative & support | 1979 |
| Headley Wood Consulting Limited | Administrative & support | 2015 |
| Headliners Recruitment Limited | Administrative & support | 2005 |
| Heads-Up Product Thinking Ltd | Information & communication | 2025 |
| Heal Coaching Ltd | Arts & recreation | 2025 |
| Health & Justice Consultancy Ltd | Health & social care | 2025 |
| Healthcare Medical Consultants Limited | Health & social care | 2011 |
| Healthio Limited | Manufacturing | 2024 |
| Hear Again Berkshire Ltd | Extraterritorial | 2026 |
| HEART2HEART Care Homes Ltd | Health & social care | 2024 |
| Heat Core Solutions Limited | Construction | 2026 |
| Heathcroft Properties Limited | Real estate | 1994 |
| Heidi Avery Salon Ltd | Health & social care | 2015 |
| Heidi Avery Tanning Ltd | Health & social care | 2015 |
| Heidi Counselling Services Ltd | Health & social care | 2026 |
| Heidi Muniko Counselling Ltd | Health & social care | 2024 |
| Heipod Developments Ltd | Construction | 2021 |
| Heirs of Sanpa Ltd | Wholesale & retail | 2012 |
| Helen O'Grady Consulting Ltd | Professional & scientific | 2021 |
| Helpinghandsit Ltd | Information & communication | 2025 |
| Hemar Consulting Ltd | Professional & scientific | 2025 |
| Hemara Design LLP | | 2022 |
| Hemp Brands Ltd | Manufacturing | 2022 |
| Henaks Limited | Manufacturing | 2022 |
| Hencroft Management Company Limited | Households | 1992 |
| Henley Advisory Services Limited | Professional & scientific | 2025 |
| Henley Financial Planning Ltd | Professional & scientific | 2025 |
| Henley Gate Freehold Limited | Real estate | 2017 |
| Henley Gate Management Limited | Households | 2011 |
| Henley Home Improvements Ltd | Construction | 2020 |
| Henshaws Ltd | Real estate | 2025 |