| Instituto Valenciano de la Edificación | |
| Insyste, S.A. | Madrid |
| Intarex, S.L. | Barcelona |
| Inte | Barcelona |
| INTECH3D | Lleida |
| Integrasoft | Segovia |
| Integrasys, S.A. | Madrid |
| Intelectium Consulting, S.L. | Barcelona |
| Intelligence Partner | Madrid |
| Intelligenia, S.A. | Granada |
| Intelligent Atlas, S.L. | |
| Interactive Digital | Murcia |
| Interantena | Sevilla |
| Interausa | Barcelona |
| Interdigital.es | Barcelona |
| Interficie | Barcelona |
| Intergrid Tecnologies del Coneixement, S.L. | Barcelona |
| interMEDIA | Asturias |
| Intermedio | Zaragoza |
| Intermega | Barcelona |
| Internacional Periféricos y Memorias España, S.L. | Barcelona |
| International Association of Science Parks and Areas of Innovation | Málaga |
| International Congress on Blockchain and Applications | Salamanca |
| International Data Computer, S.L. | Madrid |
| International Learning Authority, S.L. | Barcelona |
| International University Study Center | |
| International Venture Consultants | Madrid |
| Internet Galicia | Lugo |
| Internet Kioskos | Madrid |
| Internet Republica, S.L. | Madrid |
| Internet Security Auditors, S.L. | Barcelona |
| Internet Web Serveis | Lleida |
| Internet Web Solutions | Málaga |
| Internext | Barcelona |
| Internxt Universal Technologies, S.L. | Valencia |
| Intervia | Madrid |
| Intexmedia, S.L. | Cáceres |
| INTIA | |
| Intraempresas | Madrid |
| INTRAS | |
| Intuate | Barcelona |
| INTUIX | Barcelona |
| InvBit, diseño y desarrollo web, S.L. | A Coruña |
| Invelco, S.A. | Madrid |
| Invelon Technologies, S.L. | Lleida |
| Inventivo | Balearic Islands |
| Inveready | Barcelona |
| Invest in Spain | Madrid |
| Investigación y Programas, S.A. | Madrid |
| Invivo Capital | Barcelona |