Withdrawal of an unlawful non-beneficial administrative act

(1) Insofar as it emerges in the individual case that, in the issuing of an administrative act, the law was incorrectly applied, or the facts assumed prove incorrect, and social benefits were, as a result, wrongly not rendered, or contributions were wrongly levied, the administrative act must be withdrawn with effect for the past, even after it has become unchallengeable. This does not apply where the administrative act rests on particulars that the person concerned intentionally made incorrect or incomplete in a material respect.
(2) In other respects, an unlawful non-beneficial administrative act must, even after it has become unchallengeable, be withdrawn in whole or in part with effect for the future. It may also be withdrawn for the past.
(3) After the administrative act has become unchallengeable, the competent authority decides on the withdrawal; this applies even where the administrative act to be withdrawn was issued by another authority.
(4) Where an administrative act has been withdrawn with effect for the past, social benefits are, under the provisions of the special parts of this Code, rendered for a period of at most four years before the withdrawal. In this the point in time of the withdrawal is computed from the beginning of the year in which the administrative act is withdrawn. Where the withdrawal is made on application, the application takes the place of the withdrawal in computing the period for which benefits are to be rendered retroactively.