| Bite Investments | |
| Bitenet | Bristol |
| Bitfield Consulting | |
| Bitfount Ltd | |
| Bitjam | |
| Bitmedia Ltd | |
| Biton System Consultants Ltd | Essex |
| Bitpod Ltd | |
| Bitposter | |
| Bits 'N PC | |
| BitSolver Ltd | |
| Bitstamp Ltd | |
| Bitwise Ltd | Fife |
| Bitzesty | |
| BiVictriX Therapeutics Ltd | |
| Biz Midlands | |
| BizClik Media Group | |
| Bizdaq | |
| BizEE Software | Swansea |
| Bizimply | |
| BizMiners | Greater London |
| BizOrg Telecommunications | Lincolnshire |
| BizSpace | |
| Biztalk360 | |
| Biztechsols Ltd | |
| BizWiseIT | West Sussex |
| BJSS | |
| BK Web Design | |
| Black and Blue Software Ltd | West Sussex |
| Black And White Boy SEO & Digital Marketing | |
| Black Bear IT Solutions Ltd | |
| Black Box Network Services (UK) Ltd | Berkshire |
| Black Cat Computers Ltd | Cambridgeshire |
| Black Cat PC | West Sussex |
| Black Cherry Recruitment Ltd | |
| Black Eye Project | |
| Black Marble Ltd | |
| Black Night Software | Tyne and Wear |
| Black Pig Ltd | Hertfordshire |
| Black Poppy Design | Greater London |
| Black Rooster Digital Ltd | |
| Black Square Media Ltd | |
| Black Swan Data | |
| Blackberry Design | Worcestershire |
| Blackbone IT Group | Lancashire |
| Blackbullion | |
| Blackburn Circuit Design Ltd | Greater Manchester |
| Blackburn Communications | |
| BlackCurve Solutions Ltd | |
| BlackfinBio Ltd | |