From June 1 day, 2008, foreign exchange receipts must be written off within 2 10 days (original 180 days) after the goods are declared for export (subject to the export date indicated in the customs declaration form of export goods), and written off within 30 days after the receipt of foreign exchange.

As your foreign exchange remittance is prepaid, it can be written off within 30 days after export declaration. If the goods are not delivered all the time, there is no way to write off the money, because there is no export declaration form and there is no customs seal on the verification form of export proceeds.

Supplementary answer: Yes, it can be understood this way. The goods haven't actually been delivered, and the advance payment has been hung up, which has no influence on future write-offs. After customs clearance, you should log in to the electronic port to send the export declaration form and verification form. About a week or so, SAFE will receive the verification information. After receiving the final payment from the guest, you should log in to the foreign exchange verification system, then enter the advance payment and final payment, fill in all the information and send it to the safe. However, it should be noted that the total amount of "advance payment+final payment" should be roughly equal to the total amount of customs declaration, and only +/-5% error is allowed, otherwise it will not be written off.