| Bdon Limited | Aberdeen | 2022 |
| Bdraccess Ltd | London | 2025 |
| BE EX Limited | London | 2012 |
| Beach Energy (Otway) Limited | London | 2002 |
| Beacon Resources Limited | Honiton | 1996 |
| Beal Resources Limited | London | 2020 |
| Beam Survey Global Limited | Beaconsfield | 2025 |
| Bearcat Operations Limited | Bath | 2021 |
| Beau Engineering Ltd. | Glasgow | 2016 |
| Beaver Management Services Limited | Billingham | 1996 |
| BEC Consulting Ltd | Edinburgh | 2025 |
| BEC New Ventures Ltd | Nottingham | 2018 |
| Beck Consultancy Ltd | Great Yarmouth | 2011 |
| Bedford Brewery Plymouth Ltd | Yelverton | 2020 |
| Bedrock Drilling Consultancy Ltd | Chichester | 2010 |
| Bedrock Drilling Limited | Chichester | 2012 |
| Bedrock Mineral Group Ltd | London | 2026 |
| Bedrock Petroleum Consulting Ltd. | Swinton | 1995 |
| Beerenberg UK Ltd | Aberdeen | 2019 |
| Begg Engineering Solutions Ltd | Brechin | 2018 |
| Behre Dolbear Engineering Services Limited | Ashford | 2009 |
| Behre Dolbear International Limited | Ashford | 2017 |
| Behre Dolbear UK Limited | Ashford | 1997 |
| Beinit Energy Limited | Manchester | 2020 |
| Belamar Ltd | Folkestone | 2022 |
| Belay Access Solutions Limited | Glasgow | 2015 |
| Belgian Anter Chemical Co., Ltd | Cambridge | 2025 |
| Belgian Barna Industrial Co., Ltd | Cambridge | 2024 |
| Belgium A-Plants Energy Chemical Group Co., Ltd | Cambridge | 2025 |
| Belgium Antwerp Chemical Co., Ltd | Cambridge | 2026 |
| Belgium Fdis International Co., Ltd | Cambridge | 2026 |
| Belgium Hagerberg Chemical Co., Ltd | Cambridge | 2024 |
| Belgium Luohilton International Co., Ltd | Cardiff | 2026 |
| Belgium Mima Chemical Co., Ltd | Cambridge | 2024 |
| Belgium Oldman Crop Nutrition Co., Ltd | Cambridge | 2026 |
| Belgium Ouhenongke (China) Co., Ltd. | West Midlands, England | 2025 |
| Belgium Shiende Fertilizer Co., Ltd | Kenilworth | 2023 |
| Belgium Sicalnit International Ltd | Cambridge | 2024 |
| Believin Technology Co., Ltd | Cardiff | 2026 |
| Bell's OIL Infrastructure Limited | Chester-Le-Street | 2026 |
| Bella MIA Investments Ltd | Newry | 2014 |
| Bellanuel Limited | Stevenage | 2022 |
| Bellerophon Investment Management Limited | London | 2001 |
| Belliston Quarry Company Ltd. (the) | Leven | 1943 |
| Belltest (UK) Limited | | 2006 |
| Belltree Limited | Edinburgh | 1995 |
| Belmak Management Consultancy Limited | Glasgow | 2018 |
| Belt Engineering Services Ltd | Tobermory | 2012 |
| Belvidere Consulting Ltd | Aberdeen | 2019 |
| Bemps Mining and Petroleum Limited | Harrow | 2022 |
| BEN Bennett JR Limited | Rotherham | 1925 |
| BEN Gordon Services Limited | Elgin | 2024 |
| BEN Mair Electrical Ltd | Buckie | 2023 |
| Benacome Limited | Eastbourne | 2012 |
| Benchmark Geophysical Consulting Limited | Coleford | 1999 |
| Benchmarks Group Ltd | Guildford | 2015 |
| Bene-Tek Ltd | Montrose | 2004 |
| Benite OIL & GAS Services Limited | Great Yarmouth | 2019 |
| Bentec Solutions Limited | Portlethen | 2021 |
| Bentley Geosolutions Limited | Bury | 2009 |
| Beowulf Mining PLC | London | 1988 |
| Berbell Limited | Bromborough | 2020 |
| Beringer Offshore Ltd | Chipping Norton | 2021 |
| Berkeley Metals & Commodities Ltd. | London | 2025 |
| Berry & Marshall (Bolton Wood) Limited | Harrogate | 1956 |
| Berry Advanced Limited | Swaffham | 2014 |
| Berwyn Minerals Limited | Swansea | 2010 |
| Berwyn Slate Quarry Limited | Swansea | 1992 |
| Bespoke Wells Ltd | Kilmarnock | 2017 |
| Best Landscaping (Scot) Ltd | Glasgow | 2025 |
| Best One Gems Ltd | Wellingborough | 2025 |
| Betaland Limited | Steyning | 2003 |
| Betney COP Restoration Company Limited | Bakewell | 1996 |
| Bevan Geological Services Limited | Bristol | 2014 |
| Beyond Pertoleum Limited | Huddersfield | 2020 |
| BG Cyprus Limited | London | 2009 |
| BG Delta Limited | London | 1996 |
| BG Great Britain Limited | London | 1967 |
| BG Group Limited | London | 1998 |
| BG Hogg Projects Ltd | Falkirk | 2016 |
| BG International Limited | London | 1967 |
| BG Karachaganak Limited | London | 1996 |
| BG Kenya L10B Limited | London | 1999 |
| BG LNG Investments Limited | London | 2009 |
| BG North Sea Holdings Limited | London | 1989 |
| BG Overseas Limited | London | 2013 |
| BG Rosetta Limited | London | 2004 |
| BG South East Asia Limited | London | 1989 |
| BGM Quality Services Ltd | Wick | 2014 |
| BGP Atlantic Ltd | Cranbrook | 2013 |
| BGX Petroleum Company Ltd | Norwich | 2019 |
| BH 03 Ltd | London | 2003 |
| BH Maintenance Specialists Limited | Arbroath | 2025 |
| BH Quarries Ltd | Wigan | 2023 |
| Bhatti Zinc Resources Ltd | Hull | 2025 |
| BHP Billiton Petroleum Great Britain Limited | London | 1964 |
| BHW Services Ltd | Aberdeen | 2016 |
| Bibby Hydromap Limited | Manchester | 1997 |
| Big and Heavy Ltd. | Port Talbot | 2022 |
| Bigcrad Limited | Cardiff | 2026 |