(1) Where a competent institution of one Party has made a payment of any benefit to a person for any period or event in advance of the period or event to which it relates or has paid him any benefit for a period or event, whether by virtue of the provisions of this Convention or otherwise, and the insurance authority of the other Party afterwards decides that the person entitled to benefit for that period or event under its legislation, the competent institution of the latter Party, at the request of the competent institution of the former Party, shall deduct from the benefit due for that period or event under its legislation any overpayment which results from the advance payment of benefit paid by the competent institution of the former Party and shall transmit this sum to the competent institution of the former Party.
(2) Where a person has received social assistance under the legislation of one Party for a period for which that person subsequently becomes entitled to any benefit under the legislation of the other Party, the competent institution of the latter Party, at the request of and on behalf of the competent institution of the former Party, shall withhold from the benefit due for that period the amount by which the social assistance paid exceeded what would have been paid had the benefit under the legislation of the latter Party been paid before the amount of social assistance was determined, and shall transfer the amount withheld to the competent institution of the former Party.