The Service Users of Coordinated Auction Office in South East Europe:
| Croatia |
 |
HOPS | Hrvatski operator prijenosnog sustava d.o.o. |
|
Bosnia and Herzegovina |
 |
NOSBiH | Nezavisni operator sistema u Bosni i Hercegovini |
| Montenegro |
 |
CGES | Crnogorski elektroprenosni sistem AD |
| Albania |
 |
OST | Operatori i Sistemit te Transmetimit |
| Greece |
 |
IPTO | Independent Power Transmission Operator S.A. |
| Turkey |
 |
TEIAS | TÜRKIYE ELEKTRIK ILETIM A.S |
| North Macedonia |
 |
MEPSO | Оператор на електропреносниот систем на Република Северна Македонија |
| Italy |
 |
TERNA | TERNA S.p.A. – Rete Elettrica Nazionale |
| Kosovo |
 |
KOSTT | Operator sistemi, transmisioni dhe tregu Sh.A. |