Set-off is one of the ways to terminate obligations. It is an institute where the actual fulfilment of obligations does not occur, nor are they replaced with another obligation, but there is a mutual settlement – set-off of claims between the same creditor and debtor. It is a situation where mutual claims exist between the same persons at the same time, where the debtor from one relationship has become a creditor of his creditor from the first legal obligation relationship in another relationship. In order for set-off to occur, it is necessary that the mentioned claims meet certain legal requirements: enforceability, similarity, reciprocity, due date and set-off declaration. Therefore, it is necessary for one party to give the other a declaration, but the calculation of the claims itself occurs by meeting other requirements, even retroactively. We distinguish between consensual, legal, judicial set-off and set-off by declaration of will. In some situations, the legislator has limited the set-off, and these are claims for which it is considered that the effective fulfilment of the claim is necessary, and in this way the existence of the creditor is sought to be ensured.