| Bulldog Interactive | Leicestershire |
| Bulletpoint Marketing | Greater Manchester |
| Bulletproof | Hertfordshire |
| Bumbl Creative Ltd | |
| Bump Studios | Merseyside |
| Bureau Veritas UK | |
| Burnett & Reid, LLP | |
| Burns Statistics Ltd | |
| Burnthebook | Derbyshire |
| Burrotech | |
| Burton SEO | Staffordshire |
| Bus Solutions | Greater Manchester |
| Business & Tourism Solutions | |
| Business Advice Service Ltd | |
| Business Application Software Developers Association | Buckinghamshire |
| Business Careware Ltd | South Yorkshire |
| Business Communications | Greater London |
| Business Comuter Resources Ltd | East Sussex |
| Business Continuity Services Ltd | South Ayrshire |
| Business Green | |
| Business Integration Software Ltd | |
| Business IT Plus Ltd | West Sussex |
| Business Maps Ltd | Oxfordshire |
| Business Micro Systems (NI) | Ards and North Down |
| Business Micro Systems Ltd | |
| Business Net Solutions Ltd | Buckinghamshire |
| Business of Software | Cambridgeshire |
| Business Systems (UK) Ltd | Falkirk |
| Business Web | Greater London |
| Business Webpage Ltd | Norfolk |
| BusinessCloud | |
| BusinessGen Ltd | Cardiff |
| BusinessLDN | |
| BusiSoft Solutions | East Sussex |
| Busuu Ltd | |
| Busybee Web Design | Argyll and Bute |
| Butterworth Laboratories Ltd | |
| Buy It Direct Ltd | West Yorkshire |
| Buzz (Hessle) Ltd | |
| Buzz Digital | |
| Buzzin Media Ltd | Kent |
| BuzzSumo Ltd | |
| Buzzword | West Sussex |
| BVM Ltd | Hampshire |
| BVNK Services Ltd | |
| BW3 | Tyne and Wear |
| BWD | |
| Bynx Ltd | Warwickshire |
| Byra Digital Marketing Ltd | |
| Byte IT Computers | |