| I+D Informática | Cantabria |
| i-RME.es | Zaragoza |
| i2CAT | Barcelona |
| i2CAT | |
| i3s | Biscay |
| I6NET Solutions and Technologies | Madrid |
| Iberacces | Lleida |
| Iberbyte informática | Madrid |
| Ibercaja | |
| Ibercom | Madrid |
| Ibercrédito | Madrid |
| Iberdat Security, S.L. | La Rioja |
| Iberdrola, S.A. | Biscay |
| Ibérica de Sonorización y Telecomunicaciones IBERSONTEL, S.L. | Madrid |
| IbéricaMultimedia | Madrid |
| Iberinform Internacional, S.A.U. | Madrid |
| Ibermedia | Valencia |
| Iberpixel | Madrid |
| Ibersoft España, S.L. | Zaragoza |
| Ibersystems Solutions, S.L. | Barcelona |
| Ibertech | Madrid |
| Ibertel Towebs, S.L. | Madrid |
| Ibertrónica | Madrid |
| Iberwall Servicios Informáticos, S.L. | Barcelona |
| Iberzal Tecnología, S.L. | Segovia |
| iBoo Mobile | Barcelona |
| Ibrands | Madrid |
| ICB Services | Madrid |
| ICenter Torrent, S.L. | Valencia |
| ICFO | Barcelona |
| ICFO | |
| ICG Software | Lleida |
| ICM | Barcelona |
| Icom Spain, S.L. | Barcelona |
| iCommunity | Madrid |
| ICONS Soluciones Informáticas, S.L. | Madrid |
| Iconstudio | Madrid |
| iCREATIVOS | Burgos |
| ICS Solution | Barcelona |
| ICTI Internet Passion, S.L. | Ciudad Real |
| ID Finance | Barcelona |
| ID Grup, S.A. | Barcelona |
| ID Sistemas Informaticos | Madrid |
| Idatel | Valladolid |
| IDC Games | Madrid |
| IDC, S.A. | Barcelona |
| IDD Media Pro | Madrid |
| Iddea Soluciones Internet, S.L. | A Coruña |
| Iddeon Technologies, S.L. | Barcelona |
| Idealis | Castellón |