| Instytut Wysokich Ciśnień Polskiej Akademii Nauk | |
| Instytutu Geografii i Przestrzennego Zagospodarowania im. Stanisława Leszczyckiego Polskiej Akademii Nauk | |
| InSystem Sp. z o.o. | Masovian |
| INT4 | Greater Poland |
| INTB Sp. z o.o. | Świętokrzyskie |
| IntegraKom Sp. z o.o. | Masovian |
| Integral Solutions | |
| Integral Technologies Sp. z o.o. | Masovian |
| Integrated Solutions Sp. z o.o. | |
| Integrator Systemów Automatyki AJL-System Sp. z o.o. | Silesian |
| Integreen Sp. z o.o. | Masovian |
| Integrity Partners | |
| Inteligo | |
| InteliShop.pl | Masovian |
| InteliWISE | |
| Intellect | |
| Intelligent Logistic Solutions | |
| Intelligent Technologies S.A. | |
| Intelliseq S.A. | |
| inten.pl | Lublin |
| Intent Sp. z o.o. | Masovian |
| Inter Consult S.A. | Greater Poland |
| Inter Projekt S.A. | Masovian |
| Inter-Cel | Masovian |
| Interactive Technology | Silesian |
| INTERant | Lower Silesian |
| InterData s.c. | Łódź |
| Interdyscyplinarne Centrum Modelowania Matematycznego i Komputerowego | Masovian |
| Interface Poland Sp. z o.o. | Silesian |
| Interia.pl Sp. z o.o. | |
| Interizon | |
| interkam.pl | Masovian |
| Intermania | Lesser Poland |
| Internet Marketing | Pomeranian |
| Internet Studio Bartosz Hornik | Silesian |
| Interprom.pl | Masovian |
| Interserw | Lublin |
| INTERsoft | Podlaskie |
| Intersys Group Sp. z o.o. | Masovian |
| Intertech Sp. z o.o. | Silesian |
| INTRALOGIC | Masovian |
| introNet | Świętokrzyskie |
| INVAR Integracje Sp. z o.o. | Masovian |
| Invemax Sp. z o.o. | |
| INVENTCOM | Lesser Poland |
| Invest in Wroclaw | |
| Investmag S.C. | Silesian |
| Investment Friends Capital SE | |
| Investtech Group Sp. z o.o. | |
| Invidia | Silesian |