Until now it was mandatory for taxpayers to submit an original invoice number while reporting a Credit/debit Note in Form GSTR-1 or GSTR-6, But now GSTN provided them a facility on the portal which can be used for Reporting single credit or debit note issued regarding of multiple invoices in their Form GST Return 1 
Choose the note supply type (Regular, SEZ, DE, Export, etc.) to identify the table to which such note is related to, Indicate Place of Supply (POS) for each credit or debit note to identify the supply type (Intra-State or Inter-State), to declare Debit or Credit Notes with tax amount but without any taxable value also (however, if the note is issued for the difference in tax rate only and note value can be reported Zero, then only tax amount will be reported), Similar changes have been made when reporting an amendment to a credit note or debit note 
The Refund Module also encountered several corresponding changes. Thus, during the refund applying process, taxpayers are now able to mention such credit or debit note in the statements (furnished during filing the refund application) even without reporting the appropriate challan number.
Now the taxpayer has to select the document type from a drop-down list of the invoice/debit/credit note. The change has been provided in the process of filing refund application 
Refund on:
- Export of services with payment of tax
- An account of goods & services without payment of tax
- The account of supply of goods or services to SEZ with payment of tax
- Account of supply of goods or services to SEZ without payment of tax
- Account of Inverted duty structure
