| Company name | Reg. code |
|---|---|
| CITYSKY OÜ (former name Citysky UÜ) | 16019533 |
| CITYSEC OÜ | 10030232 |
| CITYKEY OÜ | 14563401 |
| CITYSAT OÜ kustutatud | 11161605 |
| CITYSEC CONNECTION OÜ kustutatud | 12242837 |
| CITYSEC INDUSTRY OÜ (former name OÜ CIYTSEC INDUSTRY) | 17271884 |
| CITYSEC KOOLITUS OÜ (former name Citysec Foods OÜ) | 12239025 |
| CITYSEC TURVATEENISTUS OÜ (former name Citysec Security OÜ) | 12390518 |
| CITYSEC ENERGY SOLUTIONS OÜ kustutatud | 10777043 |
| CYSKY TECHNOLOGY OÜ | 16496753 |