What a GST credit note is
A credit note reduces the value or tax of a supply already invoiced. Section 34(1) of the CGST Act lets the supplier issue one when the taxable value or tax charged was more than payable, when goods are returned, or when goods or services are found deficient. The supplier then shows it in GSTR-1, which lowers their output tax, and the buyer's input tax credit goes down by the same amount.
The time limit
Section 34(2) sets the outer limit: the credit note must be declared in the return for the month of issue, and not later than 30 November following the end of the financial year in which the supply was made, or the date of filing the annual return, whichever is earlier. The 30 November date applies from 1 October 2022 (Finance Act 2022, Notification 18/2022-CT). After that, a credit note can still be issued as a commercial document, but it does not reduce GST.
Credit notes and the buyer's IMS
Since October 2025 the supplier's tax reduction on a credit note is linked to the recipient reversing the matching credit. On the GST portal the buyer accepts, rejects or keeps pending the credit note in the Invoice Management System (IMS). Tell your buyer when you issue one, so it is acted on in time.
Credit note vs debit note
A credit note lowers the value or tax; a debit note raises it, for example when a price increase is agreed after the invoice. Both carry the same Rule 53(1A) particulars and refer to the original invoice.
Rules as read on 17-10-2026. Check with your CA before relying on them for a filing.