| 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 |
| Tenkai.pl s.c. | |
| TenodWordpressa | |
| Tequila Games Sp. z o.o. | |
| Tequila Mobile S.A. | Lower Silesian |
| Ternet Sp. z o.o. | Warmian-Masurian |
| Terrabio Sp. z o.o. | |
| TerraEye | |
| Terrry Soot Management Group | |
| TEST | Lubusz |
| Testerly | |
| Testspring | |
| TESTY | Pomeranian |
| Tetrix | Podlaskie |
| The Batteries Sp. z o.o. | |
| The BitByBit Company | |
| The Code Brothers | |
| The Coded Self | |
| The Coders | |
| The Digital Bunch | |
| The Force Code Sp. z o.o. | |
| The Heart | |
| The Humans Sp. z o.o. | |
| The Knights of U | |
| The New Look | |
| The Software House | |
| the.good.code | |
| Thorium Space | |
| THTG | |
| Tidaro | |
| Tiem4IT | |
| TigriWeb | |
| TiltUp Ltd | |
| Tim4 Digital | Silesian |
| TimeFrame Software | Lesser Poland |
| TimonWeb | |
| TMA Automation Sp. z o.o. | |
| TME Transfer Multisort Elektronik Sp. z o.o. | Łódź |
| TMSYS Sp. z o.o. | |
| Together Software | |
| TogetherData | |