| Tel-Ster Sp. z o.o. | |
| Telbit | Pomeranian |
| Telbud S.A. | Greater Poland |
| Teldat | |
| Teleaudio Diwa Sp. z o.o. Sp.k. | Masovian |
| Telecom Consulting | Masovian |
| Telekom | Silesian |
| Telekom Warmia Sp. z o.o. | Warmian-Masurian |
| Telekomfort | Silesian |
| Telemedi | |
| TelePolska Sp. z o.o. | Masovian |
| Telestrada | Masovian |
| Teletronic | Lesser Poland |
| Televoice Polska | Masovian |
| TelForceOne S.A. | Lower Silesian |
| Tels | Masovian |
| Telskol Sp. z o.o. | Masovian |
| Telvinet Sp. z o.o. | Lower Silesian |
| Tema Sp. z o.o. | Podlaskie |
| Tempora | Świętokrzyskie |
| Ten Squares Games S.A. | |
| Tenesys | |
| Tenit Internet | Silesian |
| Tequila Games Sp. z o.o. | |
| Tequila Mobile S.A. | Lower Silesian |
| Ternet Sp. z o.o. | Warmian-Masurian |
| Terrabio Sp. z o.o. | |
| TEST | Lubusz |
| TESTY | Pomeranian |
| Tetrix | Podlaskie |
| The Batteries Sp. z o.o. | |
| The Heart | |
| The Software House | |
| Thorium Space | |
| Tidaro | |
| TiltUp Ltd | |
| Tim4 Digital | Silesian |
| TimeFrame Software | Lesser Poland |
| TMA Automation Sp. z o.o. | |
| TME Transfer Multisort Elektronik Sp. z o.o. | Łódź |
| TMSYS Sp. z o.o. | |
| Tomorrow Sp. z o.o. | |
| Toolbox for HR | |
| Tooploox Sp. z o.o. | |
| Tooploox Sp. z o.o. | |
| Top Position | Silesian |
| Top2net Sp. z o.o. | Lower Silesian |
| Topological Methods in Nonlinear Analysis | Kuyavian-Pomeranian |
| Topus | Lower Silesian |
| Toucan Systems | |