| BrightRED | Lancashire |
| Brightrock Games | |
| BrightSentinel Ltd | |
| BrightSign Technology Ltd | |
| Brightwell Computers | Suffolk |
| Brill Power | |
| Brillband | |
| Brilliant Digital | Cambridgeshire |
| Brilliant Ltd | Hertfordshire |
| Bring Digital | |
| Bringo | |
| Bristol Baptist College | |
| Bristol Computer Repair | Bristol |
| Bristol Computer Support | |
| Bristol Web Design | Bristol |
| Bristol Web Design Ltd | |
| Britannia Pharmaceuticals Ltd | |
| Britannic Technologies | Surrey |
| British Blockchain Association | |
| British College of Osteopathic Medicine and European School of Osteopathy | |
| British Computer Society | Wiltshire |
| British Design Experts | Hampshire |
| British Machine Vision Association and Society for Pattern Recognition | County Durham |
| British Multi Designers | |
| British Neuroscience Association Ltd | |
| British NIC | Glasgow |
| British Private Equity & Venture Capital Association | |
| British Telecommunications plc | |
| Britweb Ltd | West Sussex |
| Brixx | |
| BRM Computers Ltd | |
| Broad Services Ltd | |
| Broadband Choice | Staffordshire |
| Broadband Cloud Solutions Ltd | Edinburgh |
| Broadband for the Rural North Ltd | Lancashire |
| Broadband Suppliers | |
| Broadband Visual Communications Ltd | Bristol |
| Broadband Wherever | Berkshire |
| Broadband.co.uk | Nottinghamshire |
| Broadbandchoices | |
| Broadberry Data Systems Ltd | Greater London |
| Broadbiz Web Services Ltd | Kent |
| Broadcast Traffic Systems | Bridgend |
| Broadgate Infonet Ltd | Greater London |
| Broadland Computers | |
| Broadland Digital Ltd | Norfolk |
| BroadLogic | |
| Broadplace Advertising Ltd | |
| Broken String Biosciences | |
| Brokertech | |