Kernrechtsfrage
Whether the IV office's refund claim against the insurer was time-barred under Art. 25 ATSG.
Extrahierter Entscheid
The one-year limitation period began when the office received the cantonal decision declaring the set-off unlawful, so the refund decision of 2006-08-10 was late.
Extrahierte Begründung
The court held that limitation periods for restitution are forfeiture periods examined ex officio. Knowledge exists only when both the ground and the amount are knowable with due diligence. Here the office learned of illegality upon service of the 2005 decision; the period ended on 2006-08-09 and was not preserved by the later request letter because no prior notice procedure applied.