| Company name | Reg. code |
|---|---|
| 2QT OÜ | 14390358 |
| QT DESIGNS OÜ | 16449400 |
| QT LIMITED OÜ | 14311887 |
| QT ENTERTAINMENT OÜ | 16216943 |
| QTP OÜ | 14308925 |
| QTH OÜ | 11599448 |
| QTM OÜ | 16735904 |
| QTBC OÜ | 16877797 |
| QTUUL OÜ | 17442245 |
| QTIME OÜ kustutatud | 16732231 |
| QTT-X OÜ | 17227512 |
| QTECH OÜ | 14680518 |
| QTM ONE OÜ kustutatud | 16444167 |
| QTHRON OÜ | 17160481 |
| QTM CORP OÜ (former name QTM COPR OÜ) | 16204615 |
| QTH ENERGY OÜ (former name OÜ QTH Metall) | 14640660 |
| QTB LINGUA OÜ kustutatud | 12248432 |
| QTMNETWORK OÜ kustutatud | 16443870 |
| QTM CONSULTING OÜ | 16523776 |
| TFGCROWD OÜ (former name QTERM Estonia OÜ) | 14278391 |
| DIGEX CO. EUROPE OÜ kustutatud (former name QTRIEurope OÜ) | 14704236 |