| Electricity Distribution Engineering Services Ltd. | Leeds | 2009 |
| Electricity Industry Run OFF Services Limited | London | 2005 |
| Electricity Network Contractors (East) Limited | Buckingham | 2018 |
| Electricity North West Limited | Stockport | 1989 |
| Electricity Plus Supply Limited | London | 2004 |
| Electricity Storage Network Limited | Exeter | 2011 |
| Electricity Supply Solutions Ltd | Derby | 2016 |
| Electrics by Ebers Ltd | Tonbridge | 2014 |
| Electripel Networks Limited | Liverpool | 2021 |
| Electriphy Ltd | Ashton-Under-Lyne | 2026 |
| Electrisol Limited | Belper | 2013 |
| Electro Cool Ltd | London | 2023 |
| Electro Fixings Ltd | Willenhall | 2019 |
| Electro Green Power Ltd | London | 2010 |
| Electro Tech (Glasgow) Ltd | Glasgow | 2018 |
| Electroad Ltd | Bungay | 2023 |
| Electrocall Limited | Ferndale | 2005 |
| Electrocity Ltd | Leeds | 2018 |
| Electron Commercial Utilities Limited | Droitwich | 2007 |
| Electron Green Limited | London | 2021 |
| Electron HV Consultants Ltd | Glasgow | 2024 |
| Electroroute Energy Limited | London | 2016 |
| Electroroute Energy Supply NI Limited | Newry | 2016 |
| Electrosmith Ltd | Sutton | 2015 |
| Electrus Generation Ltd | Belfast | 2024 |
| Electrus Wind Farm 1 Ltd | Belfast | 2024 |
| Elecvault Ltd | Leicester | 2022 |
| Elecwiz Limited | Chalfont St. Giles | 2006 |
| Elegance Energy Saving UK Ltd | Ilford | 2020 |
| ELEKTRIKA1 Ltd | London | 2020 |
| Element Commissioning Services Ltd | Gravesend | 2019 |
| Element Wind Limited | Perthshire | 2007 |
| Elemental Power Ltd | Birmingham | 2022 |
| Elementary Connect Ltd | Manchester | 2024 |
| Elementary Energy Limited | Leeds | 2012 |
| Elements Energy Ltd | Penarth | 2020 |
| Elements Green Bolney Holding Ltd | London | 2025 |
| Elements Green Development Ltd | London | 2022 |
| Elements Green Midco Ltd | London | 2025 |
| Elements Green New Midco Ltd | London | 2022 |
| Elements Green New Parent Ltd | London | 2025 |
| Elements Green Penllergaer Ltd | London | 2021 |
| Elements Green Renewables SPV001 Ltd | London | 2022 |
| Elements Green Renewables SPV002 Ltd | London | 2022 |
| Elements Green Renewables SPV003 Ltd | London | 2022 |
| Elements Green Renewables SPV004 Ltd | London | 2022 |
| Elements Green Renewables SPV006 Ltd | London | 2023 |
| Elements Green Renewables SPV007 Ltd | London | 2023 |
| Elements Green Renewables SPV008 Ltd | London | 2023 |
| Elements Green Solis Limited | London | 2023 |
| Elements Green Staythorpe Bess Ltd | London | 2021 |
| Elements Green Staythorpe Gridco Ltd | London | 2023 |
| Elements Green Trent Ltd | London | 2021 |
| Elextric Ltd | London | 2021 |
| Elfficiency Ltd | Sutton | 2008 |
| ELG Commercial 1 Limited | London | 2023 |
| ELG Commercial 2 Limited | London | 2024 |
| ELG Commercial 3 Limited | London | 2024 |
| Elgar Energy Holdings Limited | London | 2025 |
| Elgar Middleton BIO Power Limited | London | 2015 |
| Elgar Middleton Operations Limited | London | 2017 |
| Elgin Energy Italy Holdings Limited | Weybridge | 2024 |
| Elgin Grid Connections Ltd | Weybridge | 2023 |
| Elgin SM Limited | London | 2016 |
| Elin Wynt CYF | Mold | 2012 |
| Eliock Hydro Electric Company Limited | Dalkeith | 1991 |
| Elios Energy Holdings 3 Limited | London | 2017 |
| Elios Energy Holdings Limited | London | 2015 |
| Elios Renewable Energy Limited | London | 2010 |
| Elite Air M&E Ltd | Hemel Hempstead | 2023 |
| Elite Boiler Care Ltd | London | 2025 |
| Elite Building Services Solutions Ltd | Poole | 2024 |
| Elite Climate Solutions Ltd | Glossop | 2021 |
| Elite Commercial & Domestic GAS Services Ltd | Bedford | 2023 |
| Elite Complete Access Limited | Mildenhall | 2025 |
| Elite Cooling Specialists Ltd | Aberdeen | 2024 |
| Elite Electrical & Fire Ltd. | Burgh Heath | 2015 |
| Elite Electrical Solutions (North East) Ltd | Middlesbrough | 2016 |
| Elite Installation Services Limited | Ware | 2001 |
| Elite Mechanical Group Limited | Neath | 2026 |
| Elite Services Technical Solutions Limited | Dagenham | 2020 |
| Elite Solar Group Ltd | Pulborough | 2026 |
| Elite Temperature Control Limited | Fareham | 2021 |
| Eljax Energy Consultants Limited | Maesteg | 2018 |
| Elka GAS & Electrics Ltd | Oxford | 2020 |
| Ella Bioenergy Ltd | Caerphilly | 2024 |
| Elleidium Wave Power Ltd | Bury St. Edmunds | 2023 |
| Ellesmere Renewables Ltd | Bangor | 2011 |
| Ellg Energy Services Limited | Nelson | 2023 |
| Elli Solar SPV 1 Limited | London | 2013 |
| Elliott Controls Engineering Limited | Chelmsford | 2018 |
| Ellis Climate Control Ltd | Richmond | 2023 |
| Ellis Lighting Ltd | Romford | 2021 |
| Ellough AD Plant Limited | Ely | 2010 |
| Ellough Solar 2 Limited | London | 2015 |
| ELM BSI Wind Ltd | London | 2022 |
| ELM Power Limited | Stockport | 2020 |
| ELM SC Wind Farms Ltd | London | 2023 |
| ELM Solar (Darran) Limited | London | 2015 |
| ELM Solar Energy Limited | London | 2016 |