| Beat the Heat AC Ltd | Stevenage | 2024 |
| Beatrice Offshore Windfarm Holdco Limited | Perth | 2016 |
| Beatrice Offshore Windfarm Limited | Perth | 2008 |
| Beattheheat Limited | Loughton | 2007 |
| Beaufort Power Ltd | Warrington | 2014 |
| Beaufort Wind Limited | London | 2003 |
| Beaumanoir Ltd | Grantham | 2024 |
| Beaverwood Limited | Liverpool | 2021 |
| Beaverwood Pellets Limited | Liverpool | 2021 |
| Beavor Grange Solar Limited | London | 2022 |
| Beaw Field Shetland Limited | London | 2011 |
| Beba Energy UK Ltd | Hemel Hempstead | 2009 |
| BEC Energy Ltd | Manchester | 2013 |
| BEC Projects One Ltd | Bristol | 2023 |
| Beckby Biogas Limited | Guildford | 2024 |
| Becker Utilities Ltd | Bracknell | 2023 |
| Beckley Energy Limited | Christchurch | 2012 |
| Beco Electrical Limited | Coventry | 2013 |
| Bedborough Solar Farm Limited | Exeter | 2014 |
| Bedfordshire Air Conditioning Limited | Harpenden | 2019 |
| Bedfordshire Solar 1 Limited | London | 2021 |
| Bedstone Bioenergy Limited | Bromyard | 2026 |
| Bedwell Park Solar Limited | London | 2011 |
| Bedworth Solar Limited | Birmingham | 2020 |
| BEE Biglis Limited | London | 2014 |
| BEE Chard Limited | London | 2014 |
| BEE Derwen Limited | London | 2012 |
| BEE Green Energy Ltd. | Lydney | 2009 |
| BEE Green Solar Holdings Limited | Lydney | 2015 |
| BEE Nancrossa Limited | Cardiff | 2012 |
| BEE Priors Byne Limited | London | 2014 |
| BEE Smart Today Ltd | Rugby | 2018 |
| BEE Spear Hill Limited | London | 2015 |
| BEE Sutor Limited | London | 2014 |
| BEE Swanland Limited | London | 2015 |
| BEE Tump Farm Limited | London | 2014 |
| Beech Farm Solar Limited | Hove | 2014 |
| Beech Tree Farm Wind Turbine Ltd | Craigavon | 2015 |
| Beeches Solar Limited | Reading | 2015 |
| Beechgreen Energyfarm Limited | Houghton Le Spring | 2019 |
| Beechgrove Renewables Limited | Newtownards | 2013 |
| Beechgrove Solar Limited | London | 2011 |
| Beechhill Windfarm Limited | Derrylin | 2014 |
| Beechnut Electrical Limited | Aldershot | 2014 |
| Beegreen Technology Limited | Lydney | 2001 |
| Beehive Biopower (UK) Ltd | Coventry | 2019 |
| Beehive Ventures (UK) Ltd | Coventry | 2018 |
| Beeston Solar Energy Limited | London | 2013 |
| Beeswax Energy Ltd | Hove | 2020 |
| Beetley Energy Limited | London | 2003 |
| Beewired Ltd | Strood | 2010 |
| Beferleah Energy Park Limited | London | 2023 |
| Begl 4 Limited | Warrington | 2010 |
| Beighton Energy Limited | London | 1999 |
| Beili GOF Renewable Energy Ltd | Rhayader | 2016 |
| Beili-Mawr Heat Ltd | Cardiff | 2012 |
| Beinn Bhuidhe Energy Limited | Lincoln | 2009 |
| Beinn IME Hydropower Limited | Thornhill | 2025 |
| Beinn Mhor Power Limited | Glasgow | 2003 |
| Beinn NAN Oighrean Windfarm Ltd | Edinburgh | 2025 |
| Beinneun 2 Limited | London | 2023 |
| Beinneun Wind Farm Ltd | London | 2011 |
| Bel-Air Services (NI) Limited | Carryduff | 2011 |
| Belakane Solar SPV 1 Limited | London | 2013 |
| Belenus Energy Limited | London | 2015 |
| Belfast Energy Storage Company Limited | Belfast | 2019 |
| Belfast GAS Transmission Limited | Belfast | 1992 |
| Belgrave Electrical Services Limited | Haywards Heath | 2003 |
| Bellasize Limited | Goole | 2014 |
| Bellectrics Limited | Maidstone | 2021 |
| Belleknowes Generation Limited | Greenock | 2018 |
| Belleville Limited | Hereford | 2017 |
| Bellhouse Energy Limited | London | 1997 |
| Bellhydro Limited | Greenock | 2011 |
| Bellmoor Energy Park Limited | London | 2023 |
| Bellrock Offshore Wind Farm Limited | Edinburgh | 2022 |
| Bellstane Wind Limited | Edinburgh | 2013 |
| Belltown Power UK Limited | Bristol | 2015 |
| Belltown Power UK Platform 2 Limited | Bristol | 2025 |
| Belltown Power UK Wind Holdco Limited | Bristol | 2020 |
| Belltown Power UK Wind Limited | Bristol | 2020 |
| Belmont Renewable Energy Company Limited | Bolton | 2015 |
| Belper Hydro Limited | Matlock | 2025 |
| Belvedere Energy Investments Limited | London | 2011 |
| Belvedere Energy Investments Portfolio 2 Limited | London | 2011 |
| Belvoir Electrics Limited | Long Bennington | 2019 |
| Bemacs (Electrical) Limited | Corby | 2004 |
| BEN Aketil Wind Energy Limited | Edinburgh | 2003 |
| BEN and Leah Abbott Limited | Mansfield | 2019 |
| BEN Glas Power Limited | Kendal | 2014 |
| BEN MOR Hydro Limited | Edinburgh | 2011 |
| BEN SCA Wind Farm Limited | Edinburgh | 2018 |
| Benarty Electrical Ltd | Glasgow | 2026 |
| Benburb Renewables Ltd | Dungannon | 2022 |
| Bench, Plumbing, Heating and GAS Services Limited | Bristol | 2018 |
| Benchmark Electrical Solutions Limited | London | 2021 |
| Benchmark Electricians Limited | Bicester | 2018 |
| Beneco Energy Limited | Evesham | 2004 |
| Bengrove Bess Ltd | London | 2022 |
| Benmore Estate Limited | Edinburgh | 1998 |