A transaction is invalid on the bases established by the RA Civil Code by virtue of its declaration as such by a court (an avoidable transaction) or independent of such declaration (a void transaction).

A claim for the declaration of an avoidable transaction to be invalid may brought by the persons indicated in the RA Civil Code.

A claim for the application of the consequences of the invalidity of a void transaction may be brought by any interested person. The court has the right to apply such consequences on its own initiative.

Regardless whether the claim for the application of the consequences of the invalidity of a void transaction was brought with the claim for the declaration of an avoidable transaction to be invalid, the court declaring the transaction to be invalid is obliged to indicate the consequences of the invalidity of a void transaction in the final part of the judgment.

The source: iravaban.net