| GT Life Limited | Administrative & support | 2025 |
| GUIDE4LIFE Limited | Professional & scientific | 2015 |
| Gustav Group Limited | Wholesale & retail | 2018 |
| Gustora Limited | Hospitality | 2025 |
| Hakuna Mutt Tada Limited | Professional & scientific | 2019 |
| Haley Projects Ltd | Construction | 2021 |
| Halling Property Investments Limited | Real estate | 2017 |
| Hamilton Renata Limited | Administrative & support | 2003 |
| Hampshire Ductwork Services Limited | Construction | 1995 |
| Hampton Towers Management Company Limited | Households | 1988 |
| Hapi Ltd | Health & social care | 2026 |
| Happy Little Ones Ltd | Hospitality | 2017 |
| Happy PAY UK Limited | Financial services | 2025 |
| Hardwicke Property Holdings Limited | Construction | 2022 |
| Harlecon Ltd | Hospitality | 2021 |
| Hartley Pool Maintenance Limited | Administrative & support | 2003 |
| Harvest Drive Residents Association Limited | Administrative & support | 2015 |
| Harvey Design Ltd | Construction | 2019 |
| Harward's Gardening Services Limited | Administrative & support | 2023 |
| Hatfields of Crowthorne Limited | Wholesale & retail | 1965 |
| Havenform Limited | Households | 1996 |
| HBC Global Ltd | Professional & scientific | 2012 |
| Heath Cottage Management Company Limited | Real estate | 2002 |
| Heathermount Gardens (Crowthorne) Limited | Households | 1970 |
| Heathlake Park NO.1 Residents Company Limited | Households | 1992 |
| Heathpark Estates Limited | Real estate | 2025 |
| Heavens Sent GTM Services Limited | Professional & scientific | 2025 |
| Help YOU Accountancy Limited | Professional & scientific | 2014 |
| Help YOU Taxation Ltd | Extraterritorial | 2019 |
| Henchman-Price Finance Ltd | Professional & scientific | 2014 |
| Herbert Morrison Limited | Extraterritorial | 1995 |
| Heresy Hammer Limited | Information & communication | 2025 |
| Heritage Club Limited | Arts & recreation | 2013 |
| Heritage Land (Crowthorne) Limited | Real estate | 2013 |
| Herovibes Ltd | Information & communication | 2024 |
| Heuricity Ltd | Information & communication | 2025 |
| Hewett 360 Ltd | Information & communication | 2023 |
| High Grove Residents Management Company Limited | Households | 2003 |
| High Pine Investments Limited | Financial services | 2024 |
| Highgrove (Winnersh) Management Company Limited | Households | 2000 |
| Hightower Computing Limited | Information & communication | 1998 |
| Hillcrest Holdings (Berkshire) Ltd | Construction | 2024 |
| Hillside Park Freehold (Sunningdale) Limited | Real estate | 2007 |
| Hillside Park Management (Sunningdale) Limited | Real estate | 1983 |
| Hive Hydrogen Limited | Professional & scientific | 2022 |
| Hobbs Utility Services Ltd | Construction | 2025 |
| HOD Scaffolding London Ltd | Construction | 2026 |
| Homeview Builders Ltd | Construction | 2019 |
| Hook Steel Fabrications Limited | Manufacturing | 2017 |
| Horizon Building Supplies Limited | Administrative & support | 2025 |
| Horizon Windows and Doors Limited | Administrative & support | 2024 |
| Howevandyke Ltd | Professional & scientific | 2020 |
| HSY Sales Limited | Wholesale & retail | 2021 |
| Hughp Broadcast Ltd | Information & communication | 2020 |
| Hulbert Gate Management Limited | Households | 2005 |
| Humber Consultancy Services Limited | Professional & scientific | 2023 |
| Hyenergy Consultancy Limited | Professional & scientific | 2014 |
| Hyenergy Holdings Limited | Financial services | 2020 |
| I AM Energy Healer Ltd | Health & social care | 2022 |
| IAN Howlett Ltd | Construction | 2018 |
| IDC Maisonettes Ltd | Households | 2025 |
| IE Sims Ltd | Wholesale & retail | 2026 |
| IJO Power Ltd | Professional & scientific | 2024 |
| Ikon Hair Limited | Other services | 2011 |
| ILC Support Services Limited | Information & communication | 2019 |
| Illfx Ltd | Professional & scientific | 2019 |
| IMD Transport Ltd | Transport & logistics | 2018 |
| Imerlebi Ltd | Hospitality | 2024 |
| Immai Ltd | Wholesale & retail | 2024 |
| IMPROVE4U Limited | Construction | 2021 |
| Inca Financial Management Ltd | Professional & scientific | 2026 |
| Inflexion Advisory Ltd | Professional & scientific | 2015 |
| Informis Limited | Professional & scientific | 2014 |
| Infratek Consulting Limited | Information & communication | 2014 |
| INK Studio Architects Ltd | Professional & scientific | 2026 |
| Innocenti Limited | Information & communication | 2013 |
| Innovative Computers Limited | Information & communication | 1988 |
| Inspeerity Limited | Information & communication | 2018 |
| Inspired Clinical Consulting Limited | Professional & scientific | 2012 |
| Interface Force Measurements Limited | Wholesale & retail | 1994 |
| Interior Commercial Management Ltd | Professional & scientific | 2022 |
| Inventura Ltd | Construction | 1996 |
| Invitem Ltd | Information & communication | 2023 |
| IPL Pharma Services Limited | Professional & scientific | 2017 |
| Iplaato Services Ltd | Information & communication | 2022 |
| Ironduke Ltd | Professional & scientific | 2013 |
| Isoscan (UK) Limited | Manufacturing | 1994 |
| Ivinson DEV Ltd | Information & communication | 2024 |
| IWK (UK) Limited | Wholesale & retail | 2011 |
| J Lyons Advisory Limited | Professional & scientific | 2025 |
| Jackbconstruction Limited | Construction | 2022 |
| Jairos & Sons Ltd | Water & waste | 2026 |
| James Smith Web Consultancy Ltd | Information & communication | 2014 |
| Jarryd's Store Ltd | Wholesale & retail | 2024 |
| JB Trucks Ltd | Wholesale & retail | 2021 |
| JDK Automotive Limited | Wholesale & retail | 2022 |
| JDM Merchandise Limited | Wholesale & retail | 2008 |
| JEE Holdings Limited | Financial services | 2025 |
| Jelley Cats Ltd | Hospitality | 2022 |
| Jensen House Management Limited | Professional & scientific | 2013 |