First of all, it depends on what kind of export enterprise your company is. For enterprises above Class B, all documents should be collected within 180 days, and written off in time within 2 10 days, and there will be no problem. If it is a Class C enterprise (the export has not reached 12 months, or the cumulative export volume has not met the requirements and has not been upgraded to Class B or above), it must be written off within 90 days.