Can I amend Bills of Gstr1 after filing for itc refund?

A supplier can gnerally amend a wrong bill (invoice) in GSTR-1 if the error is identified and corrected before the due dte for fiing GSTR-1 for that period or if adjustments are permissible as per GST laws.

However, if the supplier has already taken a refund based on the wrong bill, amending the bill in gstr-1 might involve complexities. The supplier would likely need to adjust the tax liability or take corrective actions in subsequent returns or through other mechanisms like issuing a credit note or debit note as per GST provisions,

What if only wrong input is GSTIN no. , there is no change in invoice no. And amount. Supplier has incorrectly mentioned wrong GST no. And now bill is not reflected in GSTR 2b .