| Green Lane Residents Company Limited | Professional & scientific | 1999 |
| Green Renovation Solutions Ltd | Construction | 2025 |
| GREEN42 Ltd | Construction | 2025 |
| Greencourt Graphics Ltd | Professional & scientific | 2017 |
| Greenwich Partners Limited | Administrative & support | 2003 |
| Guthrie & Kirkwood Interior Design Ltd | Professional & scientific | 2015 |
| GWD Contractors Ltd | Construction | 2007 |
| H & B Building Construction Ltd | Construction | 2023 |
| H.S.W. Timber Co. Limited (the) | Wholesale & retail | 1961 |
| Hachi Wilson UK Limited | Wholesale & retail | 2024 |
| Hadden Enterprises Limited | Health & social care | 2010 |
| Haffenden Creative Ltd | Professional & scientific | 2025 |
| Hair and Beauty on Demand Ltd | Wholesale & retail | 2021 |
| Hair Supplies Purley Limited | Other services | 2025 |
| Haltec Building Services Limited | Construction | 2008 |
| Halubamsa Ltd | Professional & scientific | 2024 |
| Hamchem Limited | Administrative & support | 1989 |
| Hamer Contract Solutions Limited | Administrative & support | 2014 |
| Hamilton Forbes & Associates Limited | Professional & scientific | 2018 |
| Harewood Gardens Management Limited | Households | 2022 |
| Harris and Moore Bespoke Ltd | Construction | 2024 |
| Harry Legal & Advocacy Services Ltd | Professional & scientific | 2019 |
| Hatton Court Investments Ltd | Real estate | 2024 |
| Hawkes Solutions Limited | Professional & scientific | 2017 |
| Hayden VT Consulting Ltd | Professional & scientific | 2025 |
| HDF Consulting Ltd | Professional & scientific | 2014 |
| HE Real Estate Ltd | Real estate | 2016 |
| Health Alternatives Ltd | Health & social care | 2019 |
| Health Touch Ltd | Information & communication | 2014 |
| Healthpoint Technologies Limited | Administrative & support | 2000 |
| Healthy Mate Limited | Information & communication | 2018 |
| Heatflow Services Limited | Construction | 2008 |
| Heath Capital Advisory Ltd | Financial services | 2026 |
| Heath House (Wallington) Management Co Ltd | Households | 2016 |
| Heaven's Sound Ltd | Information & communication | 2025 |
| Hedges Tree Consultants Limited | Professional & scientific | 2017 |
| Hegarty Group Holdings Ltd | Financial services | 2025 |
| Hencarlo Limited | Construction | 2017 |
| Heron Carpentry Limited | Construction | 2011 |
| Herox UK Ltd | Construction | 2024 |
| Herring Holdings Ltd | Financial services | 2022 |
| HI Gloss Limited | Construction | 2012 |
| Hi-Mind Limited | Information & communication | 2017 |
| Hickson & Daughter Ltd | Wholesale & retail | 2023 |
| Hidden Clever Ltd | Information & communication | 2014 |
| Highway 42 Ltd | Real estate | 2022 |
| Hilden Estate Limited | Real estate | 2022 |
| Hilden Holdings Limited Liability Partnership | | 2018 |
| Hills Hounds Kent Ltd | Agriculture & fishing | 2022 |
| Hillview Buildings and Maintenance Ltd | Construction | 2019 |
| Hillwood House and Homes Limited | Construction | 2018 |
| Hines Group Limited | Financial services | 2026 |
| HJM Media Services Limited | Professional & scientific | 2024 |
| Hodford Group Limited | Professional & scientific | 2021 |
| Holbrook (Chislehurst) Limited | Households | 1984 |
| Holloway Group Holdings Limited | Professional & scientific | 2025 |
| Holtzwerke Limited | Construction | 2025 |
| Hoops Trading Limited | Wholesale & retail | 2013 |
| Hope Fundraising Ltd | Administrative & support | 2026 |
| Hornbrook House Limited | Construction | 2019 |
| Horsley Ltd | Information & communication | 2024 |
| House Munkey Limited | Real estate | 2020 |
| House of Balance Limited | Arts & recreation | 2022 |
| House of Beaute Limited | Other services | 2017 |
| House of Zaha Limited | Financial services | 2024 |
| House to Live Limited | Real estate | 2023 |
| Housemartyns Ltd | Real estate | 2026 |
| Howelletts Limited | Real estate | 2018 |
| Hudson Interpreting Services Ltd | Professional & scientific | 2005 |
| Huis Property Investment Limited | Construction | 2018 |
| Huis Property Limited | Real estate | 2011 |
| Hunter Heating Solutions Ltd | Construction | 2021 |
| Hurryforward Limited | Information & communication | 1986 |
| Huts Group Ltd | Construction | 2020 |
| Hvms Power Systems Engineering Limited | Extraterritorial | 2016 |
| Hysteria Machine Limited | Manufacturing | 2020 |
| I.K.Legal Consultants Limited | Professional & scientific | 2023 |
| IAM Apothecary Ltd | Wholesale & retail | 2020 |
| IB Business Advisors Group Ltd | Professional & scientific | 2024 |
| Ice Spirits Ltd | Wholesale & retail | 2024 |
| ICH Leisure Limited | Hospitality | 2019 |
| ICH Properties Ltd | Real estate | 2018 |
| Icon Properties London Ltd | Wholesale & retail | 2013 |
| ICT365 Ltd | Information & communication | 2007 |
| Ideal (Chislehurst) Properties Investments Limited | Real estate | 2015 |
| Idrimas Ltd | Administrative & support | 2016 |
| Ieuan James Limited | Other services | 2013 |
| Igmc Limited | Administrative & support | 2011 |
| Ihawu Security Limited | Administrative & support | 2024 |
| Iman Hygiene Therapy Ltd | Health & social care | 2022 |
| Imap Consulting Ltd | Other services | 2019 |
| Imperial Homes Residential (Chiselhurst) Limited | Households | 2007 |
| Imperial Mechanical Building Services Ltd | Construction | 2007 |
| Implex Design Ltd | Professional & scientific | 2020 |
| Imtech Design Limited | Professional & scientific | 1989 |
| IN Passing Limited | Information & communication | 2024 |
| IN the Frame Media Ltd | Professional & scientific | 2026 |
| In-House Cloud Solutions Limited | Information & communication | 2025 |
| Indal and Co Ltd | Professional & scientific | 2012 |
| Independence & Compliance Consultants Limited | Extraterritorial | 2008 |