Chartered Accountant
5010 Points
Joined March 2020
File your GSTR 1 with correct Supply in 1 Table and mention the credit notes in the other table.
Now, your system-generated GSTR 3B will not be able to show any tax payable in your case and will show nil tax and sale.
So, while filing the GSTR 3B mention 0 in both supply and tax figures. Claim the ITC reflected in GSTR 2B.
Now, adjust the excess credit notes balance in the next month GSTR 3B. However, because of this previous month's adjustement, your system generated GSTR 3B will differ with your actual GSTR 3B.