| Bill Connon Services Limited | Montrose | 2001 |
| Billcrest Limited | Cleveland | 1993 |
| Binagold Limited | Cobham | 2005 |
| Binding Solutions Ltd | Middlesbrough | 2016 |
| Bing Quarries Ltd | Upperton | 2025 |
| Biochron Ltd | Woking | 2019 |
| Biostratigraphic Associates (UK) Limited | Stoke On Trent | 1999 |
| Birch Vale Quarry Limited | Stockport | 1969 |
| Birchover Stone Limited | Bakewell | 2001 |
| Birks Royd Stone Sales Limited | Elland | 2003 |
| Bisichi PLC | London | 1910 |
| Bissau Exploration Company Ltd | Nottingham | 2015 |
| Bisubro Energy Consultants Ltd | Great Yarmouth | 2024 |
| Biwater Africa Ltd | London | 2023 |
| BJ Services Company Africa Limited | Aberdeen | 1992 |
| BJ Services Company Limited | Aberdeen | 1993 |
| BJ Services Company Middle East Limited | Aberdeen | 1993 |
| BJ Well Services Limited | Brechin | 2006 |
| BJA Instrumentation Ltd | Hebburn | 2023 |
| BJG Energy Services Ltd | Whitley Bay | 2020 |
| Bjoern Roesler Limited | London | 2015 |
| Black Cat Energy Services Ltd | Essex | 2007 |
| Black Diamond Drilling Services Limited | Wigan | 2016 |
| Black Dyke Developments Limited | Slaithwaite | 2015 |
| Black Gold Caledonia Group Ltd. | Glasgow | 2019 |
| Black Oak Mineral Resources Ltd | Coventry | 2025 |
| Black Pearl Global Investments Ltd | Southall | 2021 |
| Black Stone Mines Ltd | Greenford | 2025 |
| Blackflame Energy Ltd | Westminster | 2014 |
| Blackland Park Exploration Limited | Leigh-On-Sea | 1985 |
| Blackrock Contractors Ltd | Leeds | 2026 |
| Blackrock Minerals Ltd | Birmingham | 2025 |
| Blackwood Quarry Engineering Ltd | | 2006 |
| Blackwood Quarry Exports Ltd | | 2007 |
| Blairnathort Farm Renewables Ltd | Milnathort | 2014 |
| Blake Offshore Services Ltd | Buckie | 2021 |
| Blakiston Upstream Developments Limited | London | 2018 |
| Blast LOG Limited | Gerrards Cross | 2006 |
| Blasting Services Limited | Alfreton | 2000 |
| Blaxton Aggregates Limited | Doncaster | 2017 |
| Blaze Holdco Limited | Laurencekirk | 2019 |
| Blaze Manufacturing Solutions Ltd. | Laurencekirk | 2006 |
| Blazers Exploration Ltd | London | 2025 |
| Bleaklow Industries Limited | Bakewell | 1971 |
| Bleiker Surveys Limited | Glossop | 2005 |
| Bliary Stone UK Ltd | Newry | 2018 |
| BLM Well Services Ltd | Dundee | 2012 |
| Block Energy PLC | London | 2005 |
| Block Stone Ltd | Chelmsford | 1995 |
| Blockeeper PLC | London | 2025 |
| Blockware Group Ltd | London | 2018 |
| Bloomsbury Capital Assets Ltd. | London | 2012 |
| Bloomsbury Capital Commodities Ltd | London | 2021 |
| Blue Boar Stone Ltd | Holmes Chapel | 2026 |
| Blue BOY Services Limited | Montrose | 2016 |
| Blue Coach House Services Limited | Mablethorpe | 2024 |
| Blue Diamond ( Holdings ) Limited | Renfrew | 2016 |
| Blue Energy Solutions Ltd | Cowdenbeath | 2026 |
| Blue Equipment (NI) Ltd | Coalisland | 2025 |
| Blue Gate Energy Ltd | Birmingham | 2016 |
| Blue Horizon Energy Group Ltd. | Cardiff | 2020 |
| Blue Machinery (Equipment) Limited | Warrington | 2008 |
| Blue Machinery (Spares) Limited | Warrington | 2002 |
| Blue MEN FIN Ltd | Stonehaven | 2014 |
| Blue Moon Corporation Ltd | London | 2018 |
| Blue Ocean Seismic Services Limited | 110 Cannon Street | 2018 |
| Blue Planet Surveys Limited | Great Yarmouth | 2012 |
| Blue Rock Mining Services Ltd | Bishop'S Stortford | 2011 |
| Blue Skies Energy Resources Limited | Aberdeen | 1996 |
| Blue Spark Energy UK Ltd. | London | 2015 |
| Blue Survey Limited | Southampton | 2021 |
| Blue Turtle Ltd | Inverurie | 2019 |
| Bluenord Energy UK Ltd. | London | 1998 |
| Bluerock Ventures Ltd | Bath | 2016 |
| Bluestar Operator's Limited | St. Columb | 2018 |
| Bluestone Minerals Ltd | Haverfordwest | 2016 |
| Bluetechs UK Groups Limited | Kingston Upon Thames | 2013 |
| Bluewater (Floating Production) Limited | London | 1996 |
| Bluewater Inspection Ltd | Norfolk | 1999 |
| Bluewater Lancaster Production (UK) Limited | London | 2017 |
| Bluewater Sea Lion Production Company Limited | London | 2025 |
| Bluewater Services (UK) Limited | London | 1996 |
| Blumeadows Limited | Manchester | 2015 |
| BLY Emea UK Holdings Ltd | Aberdeen | 2011 |
| Bmac Contracting Ltd | Dingwall | 2022 |
| BMC (UK) Limited | London | 2014 |
| BMC (UK) NO.1 Limited | London | 2014 |
| BMC (UK) NO.2 Limited | London | 2015 |
| BMC (UK) NO.3 Limited | London | 2015 |
| BMC Metals Limited | London | 2015 |
| BMC Minerals Group Limited | London | 2015 |
| BMC Minerals Limited | London | 2015 |
| Bnboe Energies Limited | London | 2025 |
| BOA FE Mineracao (UK) Ltd | London | 2025 |
| Boast Site Services Ltd | Reading | 2018 |
| Boda Limited | Beckenham | 2025 |
| Bodman Geoscience Ltd | Chippenham | 2019 |
| Bodo RIM Limited | Rugby | 2019 |
| Bogdan Track Ltd | Northampton | 2014 |
| Bohec Energy Group Corporation Ltd | Beckenham | 2022 |