| BlueFinity International | Hertfordshire |
| Bluefish Computer Services | West Sussex |
| Bluefish Web Solutions | East Riding of Yorkshire |
| Bluefruit Software Ltd | Cornwall |
| BlueGoose | Isle of Man |
| BlueGreen Internet Marketing | Cheshire |
| Bluehoop Digital Ltd | |
| BlueJ | Kent |
| Bluejays PC Services | Greater London |
| Bluelinemedia Ltd | Gloucestershire |
| BlueOptima | |
| Bluepoint Corporation Ltd | Buckinghamshire |
| BluescreenIT | Devon |
| Blueshift Internet | Somerset |
| BlueSky Travel Systems Ltd | Greater Manchester |
| BlueStar-UK.com Ltd | Nottinghamshire |
| Bluestorm Design & Marketing Ltd | |
| BlueTree | Bristol |
| BlueTrendy Ltd | |
| Blueverse Ventures | |
| BluGem Communications Ltd | Devon |
| Blundell Apps | |
| Blundell Production Equipment Ltd | West Midlands |
| bluQube | Bristol |
| BMB Web Design | Dorset |
| BME Imaging | Berkshire |
| BMG Research Ltd | |
| BMI Solutions | Bristol |
| BMLL Technologies | |
| BMSoftware & Computer Hardware | Norfolk |
| BMT Cordah Ltd | Aberdeen |
| BMW Innovation Lab | |
| BN1 Digital | |
| Board Intelligence Ltd | Greater London |
| Boardwalk Studio | |
| Bob Design & Marketing Ltd | Bristol |
| Bob's Business | South Yorkshire |
| Bodet Ltd | Hertfordshire |
| Bodi.Me | |
| Bodynet UK | |
| Bodyswaps | |
| BOE Information Systems | |
| Boiler Room Digital | South Yorkshire |
| Bold Endeavours. | Surrey |
| Bold Internet Ltd | Hampshire |
| Bold Web Design & Hosting | |
| Boldon James Ltd | Hampshire |
| Boldyn Networks | |
| Bolster Systems Ltd | |
| Boltzbit | |