| Host Provider | Lower Silesian |
| host4u.pl | Kuyavian-Pomeranian |
| HostBill | Subcarpathian |
| HostingFirmowy.pl | Świętokrzyskie |
| Hotailors | |
| How Are You | |
| HSBC Continental Europe (Spółka Akcyjna) Oddział w Polsce | |
| HSI Sp. z o.o. | Opole |
| Hued.me | |
| Huge Thing | |
| HugeTECH Sp. z o.o. | Subcarpathian |
| Humansoft Sp. z o.o. | Masovian |
| hurtowniaGSM.pl | Lower Silesian |
| Husarion Sp. z o.o. | |
| Husarnet Sp. z o.o. | |
| HUSPI IT Consulting & Development | |
| Hustro | |
| Huuuge Games | |
| Huzar Software | Lower Silesian |
| Hycom | |
| Hyh | Silesian |
| HYS Enterprise | |
| I-NET.PL Sp. J. | Warmian-Masurian |
| i-Robots | |
| I-Systems | |
| IBC.pl | Greater Poland |
| IBCS Poland | Lesser Poland |
| IC Solutions | |
| iCenter | Lower Silesian |
| ICODA | |
| iCredit Sp. z o.o. | |
| ICsec S.A. | |
| IDEAMOTIVE Sp. z o.o. | Masovian |
| Ideamotive Sp. z o.o. | |
| IdeaPlace | |
| Ideo Sp. z o.o. | Masovian |
| Ideone.com | Pomeranian |
| IDHost.pl Sp. z o.o. | Opole |
| IDO Electronics | |
| iFEMA | Lesser Poland |
| Ignico Sp. z o.o. | |
| Ignited | |
| IISS Systemy Informatyczne Spółka Jawna | Łódź |
| Ikano Bank AB (publ) S.A. Oddział w Polsce | |
| Ikaria | Łódź |
| Ilario Sp. z o.o. | Masovian |
| iLumio | |
| Imag Centrum Oprogramowania | Greater Poland |
| Image Electronics | West Pomeranian |
| Image Recording Solutions Sp. z o.o. | Masovian |