| Azamedia | Barcelona |
| Azhor | Madrid |
| Azterlan | |
| AZTI | Biscay |
| Azuanet Soluciones Web, S.L. | Cáceres |
| Azul Telecom, S.L. | Madrid |
| Azurita system | Murcia |
| BAB | Barcelona |
| BABEL Sistemas de Información | Madrid |
| Baber S.C.P. | Barcelona |
| BackFund | Madrid |
| BackupInCloud | Madrid |
| Badiapp Technologies, S.L. | Barcelona |
| Balidea | |
| Balio Fintech, S.L. | Barcelona |
| Bamboo Energyy | Barcelona |
| Banca Pueyo, S.A. | |
| BancaMarch | |
| Banckup | Barcelona |
| Banco Bilbao Vizcaya Argentaria, S.A. | |
| Banco Bilbao Vizcaya Argentaria, S.A. | |
| Banco Cooperativo Español | |
| Banco de Albacete, S.A. | |
| Banco de Crédito Cooperativo | |
| Banco de España | |
| Banco de la Nación Argentina Sucursal en España | |
| Banco Europeo de Finanzas, S.A. | |
| Banco Finantia | |
| Banco Mediolanum, S.A. | |
| Banco Occidental, S.A. | |
| Banco Pinchincha | |
| Banco Primus | |
| Banco Santander, S.A. | |
| Bank of New Madrid | |
| BankFlip | |
| Bankinter, S.A. | |
| Banner Agencia de Publicidad | Madrid |
| Barcelona Brain Health Initiative | Barcelona |
| Barcelona Cloud Technologies | Barcelona |
| Barcelona Code School | Barcelona |
| Barcelona Graduate School of Mathematics | |
| Barcelona Health Hub | Barcelona |
| Barcelona Perl Mongers | Barcelona |
| Barcelona School of Economics | |
| Barcelona Supercomputing Center | Barcelona |
| Barcelona Supercomputing Center - Quantum Computing | Barcelona |
| Barcelona Technology School | Barcelona |
| Barcelona Ventures | Barcelona |
| Barcelona Ventures, S.L. | Barcelona |
| Barcelona Virtual | Barcelona |