If you've mistakenly issued an export invoice and declared it in GSTR-1, but the customer no longer requires the goods, you can treat it as a sales return. The correct procedure is to issue a credit note to reverse the original transaction and rectify your GST filings.
17 March 2020
We are manufacturer and issued Export Invoice and declared same in GSTR-1 for the month of Feb-2020 but unfortunately customer has sent a mail after filing return that material is not required, how can i treat that invoice or reverse that invoice.