| Company name | Reg. code |
|---|---|
| ULTRA OÜ | 11808828 |
| ULTRA B OÜ | 17357261 |
| ULTRA AD OÜ | 14857112 |
| ULTRA BIZ OÜ | 16424742 |
| ABC ULTRA OÜ (former name AE Ultra) | 11786274 |
| ULTRA LUX OÜ | 17246389 |
| ULTRA PIPE OÜ kustutatud | 12191361 |
| PLUS ULTRA OÜ | 16219870 |
| ULTRA LIGHT OÜ | 12358379 |
| ULTRA TRANS OÜ | 10974513 |
| ULTRA TRADE OÜ kustutatud | 12276820 |
| ULTRA RETAIL OÜ | 12924666 |
| ULTRA INVEST OÜ | 12025809 |
| ULTRA STELLAR OÜ | 16197178 |
| ULTRA STUDIOS OÜ | 16605337 |
| ULTRA SYSTEMS OÜ (former name Sauria System OÜ) | 12413813 |
| ULTRA ELECTRIC OÜ (former name SOOKRAFT OÜ) | 14787954 |
| ULTRA KAUBANDUS OÜ kustutatud | 10294793 |
| ULTRA WINDPOWER OÜ | 16565158 |
| ULTRA CORPORATION OÜ | 14442084 |
| ULTRA ELEKTRIJAAM 3 OÜ (former name Ultra Wind OÜ) | 12585916 |
| ULTRA ELEKTRIJAAM 2 OÜ (former name Ultra Services OÜ) | 12691759 |
| ULTRA ELEKTRIJAAM 1 OÜ (former name Ultra Estate OÜ) | 14486584 |
| NE PLUS ULTRA OÜ kustutatud | 14847823 |
| TUJU ON ULTRA OÜ | 14563304 |
| ULTRA-NUTRA EU OÜ | 17241765 |
| ULTRA COOL TECH OÜ | 16968985 |
| PLUS ULTRA KONSULTATSIOONID OÜ | 17120317 |
| ULTRA TENDENCY CAPITAL OF ESTONIA OÜ | 14932374 |
| ULTRAX OÜ | 10081488 |
| GSX ULTRAN OÜ kustutatud | 11875569 |
| VENNAD ULTRAD OÜ | 12456934 |
| ULTRAS ARTWORKS OÜ kustutatud | 14546108 |
| ULTRAVA OÜ | 17471442 |
| ULTRAFIT OÜ | 14013348 |
| ULTRAFON OÜ kustutatud | 12015455 |
| ULTRAMAN OÜ kustutatud | 12468582 |
| ULTRAPRO OÜ (former name UltraPro UÜ) | 16729051 |
| ULTRAMAA OÜ | 16702891 |
| ULTRAKUB OÜ kustutatud | 11551499 |
| ULTRAFORM OÜ | 12764004 |
| ULTRANEON OÜ | 16171465 |
| ULTRATONE OÜ kustutatud | 12020611 |
| ULTRAPLUS OÜ kustutatud | 11808834 |
| ULTRAMARK OÜ kustutatud | 11405941 |
| ULTRALINE OÜ kustutatud | 12511792 |
| ULTRALEET OÜ | 14341532 |
| ULTRANORD OÜ (former name Ultranord UÜ) | 17311388 |
| ULTRACORE OÜ kustutatud (former name Ultracore UÜ) | 14031174 |
| ULTRAMONT OÜ kustutatud | 12226318 |