| Bigle Legal | Barcelona |
| Biguntek | Gipuzkoa |
| Biko2 2006, S.L. | Madrid |
| Bilnea Digital, S.L. | Murcia |
| BIM Informàtica, S.L. | Barcelona |
| Binaria Web Services, S.L. | Barcelona |
| Binary Systems | Santa Cruz de Tenerife |
| Bincore Servicios Informáticos | Madrid |
| Binsoft | Barcelona |
| Bio-One, S.L. | Barcelona |
| Bioaccez | Barcelona |
| BioBam Bioinformatics | Valencia |
| Biocat | Barcelona |
| Bioga | |
| Bioiberica | Barcelona |
| Bioingenium | Barcelona |
| BIOMAR Microbial Technologies | León |
| Biomedal, S.L. | Sevilla |
| Bioo | Barcelona |
| BioSim | Madrid |
| Bit2Me | Valencia |
| Bitban Technologies, S.L. | Madrid |
| Bitel Group | Valladolid |
| BITmarketing Online SLNE | Alicante |
| BitMetrics | Barcelona |
| Bitnis.com | Pontevedra |
| Bitnova Identificación y Control, S.L. | Murcia |
| Bitnovo | Valencia |
| Bits | Madrid |
| Bittacora Informática y Diseño, S.L. | Badajoz |
| Bittopia.com | Madrid |
| Bizkaia Formación | Biscay |
| Black Elk Studios | Málaga |
| Blamar Automatización y control, S.A. | Madrid |
| Blast Off Partners, S.L. | Castellón |
| Bloc d'apple en català | Barcelona |
| Blockchers | Navarre |
| Blogalia | Las Palmas |
| Blogestudio, S.L. | Valencia |
| BlogsterApp Ambassador, S.L. | Madrid |
| Bloobirds | Barcelona |
| Bloomium | Barcelona |
| BlueFloat Energy International, S.L.U. | Madrid |
| Bnext | Madrid |
| BNP Paribas, S.A. | |
| Bocetos | Madrid |
| Bold Valuable Technology Spain, S.L. | Barcelona |
| Bonet-Galiano-Angulo S.I. S.L. | Valencia |
| Bonsai Partners | Madrid |
| Bonsai Venture Capital | Madrid |