| Brompton Technology Ltd | |
| Bronco | North Yorkshire |
| Brookland Computer Services Ltd | Greater London |
| Brother UK Ltd | Greater Manchester |
| Broughton Software Ltd | North Yorkshire |
| Brovanture | Surrey |
| Browndog Design Ltd | |
| Browser Media | Essex |
| Broxden | Perth and Kinross |
| Broxden Ltd | |
| Brunel University - Computer Science | Greater London |
| Brunel University London | Greater London |
| Brunning Software | Essex |
| BRV Technologies Ltd | Buckinghamshire |
| Bryant Unlimited | Greater London |
| Brytlyt | |
| BSG Computer Systems Ltd | Gibraltar |
| BSolve IT | Northamptonshire |
| BSS Software | |
| BT Group plc | County Durham |
| BTCminer | |
| BTCSoftware Ltd | |
| BTI Computer Systems | |
| BTP UK | Hampshire |
| BTP Works | |
| BTS Holdings plc | Greater London |
| BTS Ltd | Berkshire |
| Bubbl Ltd | |
| Bubble Automation | Hampshire |
| BubbleIT Solutions Ltd | Nottinghamshire |
| Bubblo | |
| Buckhill Ltd | Berkshire |
| Buckinghamshire New University | Buckinghamshire |
| Bucks Hubs | |
| Bud | Greater London |
| Bud Systems | |
| Buddycloud Ltd | |
| Budgeting Solutions | Nottinghamshire |
| Bueno Europe Ltd | |
| Buffalo Technology | Berkshire |
| Bug Free IT | Northamptonshire |
| Builder.ai | Greater London |
| Builder.ai | |
| BuildingBrands.Agency | |
| Built By Us | |
| Bulb UK Operations Ltd | |
| Bulbshare | |
| Bulgin Ltd | |
| Bull Marketing Ltd | Berkshire |
| Bulldog Digital Media Ltd | |