| Company name | Reg. code |
|---|---|
| TDK OÜ | 16622040 |
| TDK TRADE OÜ kustutatud | 12751527 |
| TIK-TAK OÜ | 10296562 |
| TDU OÜ | 14609822 |
| TDI2030 OÜ | 14402481 |
| KDK OÜ | 17170404 |
| TKK OÜ | 12975758 |
| ADK OÜ | 10087491 |
| TDA OÜ | 14713821 |
| TBK OÜ kustutatud | 12197692 |
| MDK-137 OÜ | 17334254 |
| TOK OÜ | 14303129 |
| TGK OÜ | 16566726 |
| TLK OÜ (former name TT Academy OÜ) | 11062234 |
| TRK OÜ | 10831601 |
| RDK OÜ | 16325371 |
| TPK OÜ | 17024938 |
| KDK4 OÜ | 14437284 |
| TJK OÜ | 12393200 |
| TLK+1 OÜ kustutatud | 14283065 |
| TDV EDITION OÜ | 14695454 |
| TMK CONSULTING OÜ kustutatud | 14739461 |
| TLK LAB OÜ | 16263173 |
| TRK CONSULTING OÜ | 14832000 |
| TFK INVESTMENTS OÜ | 16988108 |
| TFK HOLDINGS OÜ | 16988539 |
| TLK INVESTMENTS OÜ | 16468159 |
| TLK PRIVAAT OÜ | 12470969 |
| TBK LAHENDUSED OÜ | 14318697 |
| CDK INVEST OÜ | 14838706 |
| TJK WORKS OÜ kustutatud | 12682683 |
| TDF GROUP OÜ | 14838244 |
| KARAT TDG OÜ | 17273080 |
| TRK INVEST OÜ | 16568725 |
| TEK MANAGEMENT OÜ (former name Uptick trade systems OÜ) | 14614177 |
| TDF TRANS OÜ kustutatud | 14377547 |
| TEK HOLDING OÜ | 16082164 |
| TDC SOLUTIONS OÜ kustutatud (former name Skodins OÜ) | 16283856 |
| TDD EESTI OÜ | 14328419 |
| TDR AUTO OÜ kustutatud | 14730883 |
| TKD STUUDIO OÜ | 14171662 |
| TDS RESOURCES OÜ | 12969640 |
| GEOS TEK OÜ | 10854602 |
| TEK5 EST OÜ (former name Tähevara OÜ) | 12789257 |
| TRK TEENUSTE OÜ | 11227416 |
| ARNIS LDK OÜ | 12423349 |
| DDK PRIMEWORKS OÜ | 17143838 |
| TDG ENGINEERING OÜ | 12784018 |
| TKD COMMERCE OÜ | 17420433 |
| TDJ BRANDS OÜ | 17044409 |