| Charge IT NOW Limited | Norwich | 2024 |
| Charge NOW Limited | Norwich | 2024 |
| Chargeav Limited | London | 2026 |
| Charged Infrastructure Limited | London | 2017 |
| Chargenchill Ltd | Burton-On-Trent | 2021 |
| Chargeuk Ltd | Walton-On-Thames | 2020 |
| Charging Network Ltd | Newtownards | 2019 |
| Charja Energy Limited | Crickhowell | 2024 |
| Charles.Robinson Ltd | Berkhamsted | 2019 |
| Charlesfield AD Limited | Lockerbie | 2014 |
| Charlton Park Biogas Limited | London | 2016 |
| Charm Heaven Ltd | Newcastle Upon Tyne | 2012 |
| Charmwood Solar Farm Limited | Arundel | 2022 |
| Charnan Hydro Ltd | Leeds | 2017 |
| Chase EV Charging Ltd | Brownhills | 2024 |
| Chase Installations Limited | Stafford | 2002 |
| Chatleigh Energy Limited | Bath | 2014 |
| Chatteris Turbine Limited | Huntingdon | 2014 |
| Chatterley Energy Storage Limited | London | 2021 |
| CHC Group Limited | Co.Armagh | 1969 |
| Checkers Energy Limited | Edinburgh | 2021 |
| Checkley Wood Energy Limited | Leighton Buzzard | 2015 |
| Cheeky Chargers Ltd | Coventry | 2023 |
| Chelsea Air Conditioning Ltd | London | 2016 |
| Chelsea Bridge Construction Company Limited | London | 2018 |
| Chelson Meadow Community Solar Limited | Plymouth | 2023 |
| Chelson Meadow Energy Limited | London | 1997 |
| Chelveston Renewable Energy Limited | Rushden | 2005 |
| Chelwood Solar Limited | London | 2014 |
| Chelworth Community Solar Limited | Scorrier, Redruth | 2013 |
| Cheniere Marketing Ltd | London | 2013 |
| Cherry Energy Limited | Ballymena | 2013 |
| Chertsey Quarry Solar Limited | London | 2014 |
| Cheshire Air Conditioning Ltd | Runcorn | 2025 |
| Cheshire Climate Control Limited | Ashton-Under-Lyne | 2005 |
| Cheshire Coppice PV Ltd | Saffron Walden | 2014 |
| Cheshire Farm Battery Storage Limited | Stonehouse | 2022 |
| Cheshire Heating Solutions Limited | Widnes | 2019 |
| Cheshire Home Solutions Limited | Runcorn | 2023 |
| Cheshire Renewable Energy Holdings Ltd | London | 2015 |
| Chessgrove Energy Limited | Hanbury | 2022 |
| Chessington Bess Ltd | London | 2022 |
| Chester Energy Storage Limited | Maidenhead | 2024 |
| Chestnut Solar Farm Limited | Rothley | 2023 |
| Cheverton Down Wind Farm C.I.C. | Berkeley | 2015 |
| Chevin Electrical Limited | Leeds | 2009 |
| CHF Air Conditioning Ltd | Accrington | 2020 |
| CHF Sustainability Limited | Maidstone | 2020 |
| Chhokar GAS Services Ltd | Oldbury | 2019 |
| Chichester Power Limited | Chichester | 2014 |
| Chickenhawk Limited | London | 2014 |
| Chickerell Storage 2 Limited | London | 2023 |
| Chickerell Storage Limited | London | 2018 |
| Chiko GAS & Heating Services Ltd | Sheffield | 2016 |
| Chill Factor Services Ltd | Manchester | 2017 |
| Chill IT Automotive Ltd | Gloucester | 2024 |
| Chillair Solutions Ltd | Longfield | 2024 |
| Chiller Technical Solutions Limited | Bristol | 2001 |
| Chilly Baltic Trailer Hire Ltd | London | 2025 |
| Chilly Penguin Ltd | Gloucester | 2025 |
| Chiltern AD Management Ltd | Fakenham | 2017 |
| Chiltern Edge Energy Reserve Ltd | London | 2025 |
| Chilton Cantello Solar Park Ltd | London | 2012 |
| Chimax Electrical Contractor Ltd | London | 2013 |
| Chimmens Energy Limited | Kings Langley | 2022 |
| China Jinko Energy Technology Co., Ltd | Gillingham | 2025 |
| China Jinkoao Technology Co., Ltd | Gillingham | 2025 |
| China National Petroleum Corporation Limited | Cambridgeshire | 2017 |
| Chint Solar UK Management Ltd | London | 2023 |
| Chiplow Wind Farm Limited | London | 2014 |
| Chirmorie Wind Farm Limited | London | 2014 |
| Chisbon Solar Farm Holdings Limited | London | 2013 |
| Chisbon Solar Farm Limited | London | 2013 |
| Chittering Solar Limited | Bristol | 2011 |
| Chittering Solar Two Limited | London | 2012 |
| Chleansaid Wind Farm Limited | London | 2025 |
| CHM Airconditioning Ltd | Whetstone | 2023 |
| Chohan Capital Holdings Ltd | Birmingham | 2025 |
| Chonais Hydro Limited | Edinburgh | 2013 |
| Chopard Energy Limited | London | 2017 |
| CHP Energy NO.1 Limited | Derby | 2021 |
| Chrgup Limited | London | 2022 |
| Chris Hezlett Ltd | Worcester | 2013 |
| Chris Hopkins Electrical Ltd | Crawley | 2012 |
| Chris Hudson Electrical Installations Limited | Faversham | 2017 |
| Chris Lowrie Jointing Services Ltd | Windsor | 2025 |
| Chris Plant Utilities Ltd | Dudley | 2019 |
| Christ Church Library Services Limited | Eastleigh | 1994 |
| Christchurch Energy Limited | Christchurch | 2020 |
| Christchurch Refrigeration Ltd | Norwich | 2026 |
| Christian Electrical Services Ltd | Cheshunt | 2021 |
| Chrome Hvac Installations Ltd | London | 2022 |
| Church Energy Savings Co Ltd | Poole Road, Branksome, Poole | 2015 |
| Church Energy Savings Consortium Limited | Poole | 1999 |
| Church Farm Energy Centre Limited | Essex | 2019 |
| Church Hill Wind Farm Limited | Belfast | 2004 |
| Church Lane Solar Farm Limited | Aylesbury | 2023 |
| Church Minshull Community Hydro CIC | Totnes | 2017 |
| Churchtown Farm Solar Limited | Kings Langley | 2011 |
| Cikabou Ltd | London | 2023 |