| Hipe Trains Ltd | Houghton Le Spring | 2026 |
| Hire Charge Limited | Winchester | 2012 |
| Hirst Solar Energy Limited | Stockton-On-Tees | 2015 |
| Hirwaun Energy Limited | Aberdare | 2016 |
| Histon Power Limited | London | 2025 |
| HIT Finance Consulting Management Ltd | London | 2023 |
| Hitchcox Holdco 2 Limited | London | 2026 |
| Hitec Services Limited | Dronfield | 2005 |
| Hive Renewables Limited | Romsey | 2023 |
| Hive Solar Limited | Romsey | 2022 |
| HJB Electrical Ltd | Beccles | 2016 |
| HJB Turbines Ltd | Manchester | 2023 |
| Hjec Limited | Bridgend | 2014 |
| HJW Electrical Limited | Thornton-Cleveleys | 2019 |
| HK Air Conditioning Limited | Romney Marsh | 2025 |
| HK Green Energy Services Ltd | Tilbury | 2022 |
| Hkexcavations Limited | Gillingham | 2019 |
| HL Air Conditioning Services Limited | Chertsey | 2021 |
| HLM Enterprises Limited | Wellingborough | 2022 |
| HLR Utilties Ltd | Sandhurst | 2024 |
| HM Carlton Forest Ltd | Ashford | 2017 |
| HM Energy UK Limited | London | 2015 |
| HM GB (Wind) Ltd | Ascot | 2020 |
| HMA Electrical Services Limited | High Wycombe | 2013 |
| HMF Engineering and Project Management Consultants Ltd | Newcastle | 2022 |
| HMS Utilities Ltd | Glasgow | 2019 |
| HN Cooling Ltd | Morden | 2023 |
| HOB Lane Solar Farm Limited | Bristol | 2022 |
| Hoback Solar Ltd | Gatwick | 2011 |
| Hoblai Limited | Wimborne | 2022 |
| Hoborough's Dyke Power Limited | Norwich | 1999 |
| Hockliffe Green Energy Centre Ltd | Faversham | 2022 |
| Hoddesdon Energy Ltd | Hoddesdon | 2014 |
| Hoku Infrastructure Limited | London | 2024 |
| Hola Solar Ltd | Bury St. Edmunds | 2026 |
| Holbeach Biogas Limited | Bedford | 2011 |
| Holbeach Energy Park Limited | London | 2021 |
| Holbein Property Innovation Ltd | Covent Garden | 2023 |
| Holborn Energy Limited | Birmingham | 2012 |
| Holder Air Conditioning Limited | Carshalton | 2015 |
| Holemoor Solar Ltd | Exeter | 2023 |
| Hollamoor Limited | London | 2011 |
| Holland Park Services Limited | West Wickham | 2009 |
| Holly Farm Solar Park Limited | Bristol | 2013 |
| Hollybush Bess Ltd | London | 2022 |
| Hollygreen Energyfarm Limited | Sunderland | 2024 |
| Hollypark Farm Energy Ltd | Omagh | 2011 |
| Holme Bioenergy Limited | Gainsborough | 2018 |
| Holme Hydro Limited | Evesham | 2013 |
| Holme Infrastructure Projects Limited | Wareham | 2014 |
| Holme Lane Bess Limited | London | 2022 |
| Holme Wood Lane Energy Centre Limited | Rochford | 2025 |
| Holmes Air Conditioning Ltd | Harrow | 2023 |
| Holsen Limited | Belfast | 2014 |
| Holtair Limited | Brentwood | 2023 |
| Holton Solar Farm Limited | Reading | 2012 |
| Holtwood Solar Limited | London | 2013 |
| Holyhead Deep Limited | Holyhead | 2016 |
| Home Air-Conditioning Ltd | Barnsley | 2025 |
| Home Energy Limited | Manchester | 2016 |
| Home Energy Trading Ltd | London | 2016 |
| Home Farm Solar 1 Limited | Hove | 2014 |
| Home Farm Solar Limited | Warrington | 2018 |
| Home-Air Ltd | East Boldon | 2005 |
| Homeco Technologies Limited | Chesterfield | 2008 |
| Homeland Electrical Services Ltd | Wirral | 2020 |
| Homeland Solar Limited | London | 2013 |
| Homer Renewables Limited | London | 2024 |
| Homestead Community Solar C.I.C. | London | 2015 |
| Homesun 2 Limited | Reading | 2011 |
| Homesun 3 Limited | Reading | 2011 |
| Homesun 4 Limited | Reading | 2011 |
| Homesun 5 Limited | Reading | 2011 |
| Homesun Holdings Limited | London | 2023 |
| Homesun Limited | Reading | 2010 |
| Honest Heating Ltd | London | 2022 |
| Honest Power Ltd | Sunderland | 2022 |
| Honeysome Road Solar Limited | Hove | 2015 |
| Hong-Hai-Er Facilities Services Ltd | Ruislip, | 2024 |
| Honingham Gridco Ltd | Norwich | 2022 |
| Honister Energy Limited | Kendal | 2015 |
| Hook Moor Wind Farm Limited | London | 2007 |
| Hook Valley Farm Solar Park Limited | London | 2012 |
| Hoolan Energy Limited | London | 2015 |
| Hoon HAY Solar Limited | Slough | 2020 |
| Hoopers Pool Solar Farm Limited | Bristol | 2022 |
| Hooton BIO Power Limited | London | 2015 |
| Hooton Pagnell Renewables Limited | Shepton Mallet | 2025 |
| Hope Energy Ltd | Birmingham | 2020 |
| Hope Solar Park Limited | Exeter | 2012 |
| Hopetoun Renewables Limited | Edinburgh | 2010 |
| Hopi Co. Ltd | London | 2018 |
| Hoppit Energy Ltd | Ballynahinch | 2025 |
| Hops Energy Limited | London | 2013 |
| Hopsrig Wind Farm Limited | Motherwell | 2015 |
| Horizon Nuclear Power Limited | Slough | 2008 |
| Horizon Nuclear Power Oldbury Limited | Slough | 2009 |
| Horizon Nuclear Power Services Limited | Slough | 2009 |
| Horizon Nuclear Power Wylfa Holdings Limited | Slough | 2015 |
| Horizon Nuclear Power Wylfa Limited | Slough | 2009 |