| Conrad (Flitwick) Limited | Abingdon | 2020 |
| Conrad (Gloucester) Limited | Abingdon | 2022 |
| Conrad (Glyme) Holdco Limited | Abingdon | 2022 |
| Conrad (Glyme) Limited | Abingdon | 2022 |
| Conrad (Goose House Lane) Limited | Abingdon | 2020 |
| Conrad (Grain) Limited | Abingdon | 2020 |
| Conrad (Halesworth) Limited | Abingdon | 2021 |
| Conrad (Hawarden) Limited | Abingdon | 2017 |
| Conrad (Heybridge) Limited | Abingdon | 2016 |
| Conrad (Langage) Limited | Abingdon | 2017 |
| Conrad (Langstone) Limited | Abingdon | 2020 |
| Conrad (Larport) Limited | Abingdon | 2016 |
| Conrad (Lawford) Limited | Abingdon | 2020 |
| Conrad (Lester Way) Limited | Abingdon | 2020 |
| Conrad (Letchworth) Limited | Abingdon | 2020 |
| Conrad (Lillyhall) Limited | Edinburgh | 2014 |
| Conrad (Lower Dunton) Limited | Abingdon | 2020 |
| Conrad (Lowestoft) Limited | Abingdon | 2020 |
| Conrad (Malmesbury) Limited | Abingdon | 2021 |
| Conrad (Matching) Limited | Abingdon | 2017 |
| Conrad (Melksham) Limited | Abingdon | 2017 |
| Conrad (Middleton Junction) Limited | Abingdon | 2017 |
| Conrad (Middlewich) Limited | Abingdon | 2018 |
| Conrad (Midsomer) Limited | Abingdon | 2020 |
| Conrad (Minehead) Limited | Abingdon | 2020 |
| Conrad (Moorfield) Limited | Abingdon | 2020 |
| Conrad (Neston) Limited | Abingdon | 2021 |
| Conrad (Newark) Limited | Abingdon | 2020 |
| Conrad (Oldbury) Limited | Abingdon | 2020 |
| Conrad (Plymouth Rock) Limited | Abingdon | 2020 |
| Conrad (Plymouth) Limited | Abingdon | 2017 |
| Conrad (Purfleet) Limited | Abingdon | 2016 |
| Conrad (Putnoe) Limited | Abingdon | 2015 |
| Conrad (Rake Lane) Limited | Abingdon | 2020 |
| Conrad (Redbourn) Limited | Abingdon | 2015 |
| Conrad (Redfield) Limited | Abingdon | 2020 |
| Conrad (Redscar) Limited | Abingdon | 2018 |
| Conrad (Riversmeet) Limited | Abingdon | 2025 |
| Conrad (Runcorn) Limited | Abingdon | 2017 |
| Conrad (Sandon) Limited | Abingdon | 2023 |
| Conrad (Sandycroft) Limited | Abingdon | 2017 |
| Conrad (Shepperton) Limited | Abingdon | 2022 |
| Conrad (Sittingbourne) Limited | Abingdon | 2016 |
| Conrad (ST Philips) Limited | Abingdon | 2021 |
| Conrad (Stability Services) Limited | Abingdon | 2025 |
| Conrad (Stevenage a) Limited | Abingdon | 2015 |
| Conrad (Stevenage B) Limited | Abingdon | 2015 |
| Conrad (Sudmeadow) Limited | Abingdon | 2020 |
| Conrad (Sundon) Limited | Abingdon | 2020 |
| Conrad (Swindon) Limited | Abingdon | 2017 |
| Conrad (Thames) Limited | Abingdon | 2021 |
| Conrad (Torquay) Limited | Abingdon | 2021 |
| Conrad (Trafalgar Park) Limited | Abingdon | 2020 |
| Conrad (Walpole) Limited | Abingdon | 2022 |
| Conrad (Watchet) Limited | Abingdon | 2023 |
| Conrad (Water Lane) Limited | Abingdon | 2020 |
| Conrad (Winchester) Limited | Abingdon | 2017 |
| Conrad (Windrush) II Holdco Limited | Abingdon | 2022 |
| Conrad (Windrush) II Limited | Abingdon | 2022 |
| Conrad (Witham) Limited | Abingdon | 2020 |
| Conrad (Wootton) Limited | Abingdon | 2020 |
| Conrad (Wrexham) Limited | Abingdon | 2017 |
| Conrad (Wroughton) Limited | Abingdon | 2017 |
| Conrad (Yaxley) Limited | Abingdon | 2020 |
| Conrad (Yeovil) Limited | Abingdon | 2017 |
| Conrad Cleveleys (Holdings) Limited | Abingdon | 2015 |
| Conrad Energy (CHP) Limited | Abingdon | 2022 |
| Conrad Energy (Solar Developments) Limited | Abingdon | 2022 |
| Conrad Energy (Solar Operations) Limited | Abingdon | 2023 |
| Conrad Energy (Trading) Limited | Abingdon | 2017 |
| Conrad Energy Limited | Abingdon | 2015 |
| Conrad Lytham (Holdings) Limited | Abingdon | 2015 |
| Consall Hydro Limited | Stoke-On-Trent | 2013 |
| Consensus Power Ltd | London | 2021 |
| Consensus Power Trading PLC | London | 2022 |
| Conservice Limited | Chard | 1998 |
| Considered Systems Ltd | London | 2022 |
| Constant Cooling Limited | Cambridge | 1991 |
| Constantine Energy Holdings Limited | London | 2022 |
| Constantine Energy Midco Limited | London | 2023 |
| Constantine Storage Holdings Limited | London | 2023 |
| Consultoria WTE Grimsby Ltd | Bridgwater | 2022 |
| Consus Energy Limited | Southsea | 2025 |
| Contact Renewables and Solar Ltd | Preston | 2022 |
| Contactus Electrical Ltd | Skewen | 2018 |
| Containair Limited | Oldham | 2025 |
| Contigo Innovations Ltd | London | 2022 |
| Contourglobal Solutions (Northern Ireland) Limited | 42-46 Fountain Street | 2007 |
| Contract Natural GAS 2 Limited | London | 2004 |
| Contract Natural GAS Limited | London | 1994 |
| Control Communications Limited | Wakefield | 2024 |
| Control Electric Ltd | Warmley | 2017 |
| Controlled Air Solutions Limited | London | 1998 |
| Controlled Temperature Air Conditioning Ltd | Egerton | 2023 |
| Contronics DRY Misting Limited | Chichester | 2019 |
| Contullich Energy Storage Limited | Kings Langley | 2022 |
| Convex Energy Limited | Billingham | 2018 |
| Conway Energy Limited | Magherafelt | 2015 |
| Conway Energy NO 2 Limited | Manchester | 2007 |
| Conway Holdings Limited | Magherafelt | 2015 |