| InfoNET d.o.o. | City of Zagreb |
| InfoPlus d.o.o. | City of Zagreb |
| Informatička podrška d.o.o. | City of Zagreb |
| Infos Plus d.o.o. | |
| Infosistem d.d. | City of Zagreb |
| Infoss Slatina | Virovitica-Podravina |
| ING servis | City of Zagreb |
| InGames j.d.o.o. | Primorje-Gorski Kotar |
| ININ d.o.o. | Brod-Posavina |
| Inis d.o.o. | |
| Inity Agency | |
| Innova Software | Varaždin |
| Innovation Ads Croatia | Primorje-Gorski Kotar |
| Innovation Studio | |
| Inpro d.o.o. | Međimurje |
| Insieme j.d.o.o. | Split-Dalmatia |
| InSky Solutions d.o.o. | Zagreb |
| inspiracija.com | City of Zagreb |
| Instal Eršek d.o.o. | City of Zagreb |
| Instar Centar | |
| Institut Ruđer Bošković | City of Zagreb |
| Institut za elektroprivredu d.d. | |
| Institut za fiziku | |
| InsulaBit j.d.o.o. | City of Zagreb |
| IntegraCAD | Primorje-Gorski Kotar |
| Intel d.o.o. | |
| Inter-BIZ | Varaždin |
| Inter-Comp d.o.o. | |
| Interactive1 Zagreb d.o.o. | City of Zagreb |
| Interdata d.o.o. | City of Zagreb |
| Internetske stranice Nacionalnog CERT-a | City of Zagreb |
| InterSoft d.o.o. | |
| INTERWEB d.o.o. | Primorje-Gorski Kotar |
| Intesis d.o.o. | City of Zagreb |
| Inventa IR2 d.o.o. | City of Zagreb |
| Inventum | City of Zagreb |
| Ipos | City of Zagreb |
| Ipsum d.o.o. | Dubrovnik-Neretva |
| Iqmedia | Požega-Slavonia |
| Irata d.o.o. | City of Zagreb |
| Iskon Internet d.d. | City of Zagreb |
| Istra Tech d.o.o. | Istria |
| IT Jedan d.o.o. | City of Zagreb |
| IT.inteligentne tehnologije d.o.o. | City of Zagreb |
| Item d.o.o. | Split-Dalmatia |
| IV Ci d.o.o. | City of Zagreb |
| Izrada web stranica | Krapina-Zagorje |
| J-Sistem d.o.o. | Međimurje |
| Jadran Informatika d.o.o. | Primorje-Gorski Kotar |
| Jadrija d.o.o. | City of Zagreb |