If the advance payment cannot be exported for more than 30 days, it must be declared on the application service platform of the State Administration of Foreign Exchange within 30 days. Specifically: log in to the system, select the prepayment report, enter the enterprise code and collection time of prepayment, and click Query to display the related contents of prepayment. Select the collection to be declared, enter the amount to be declared and the expected export date when declaring, and then confirm.