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GST · 26 June 2026

Credit Note vs Debit Note Under GST: When Do You Issue Each?

A credit note and a debit note under GST are the two documents that correct a tax invoice after it has been issued, both governed by Section 34 of the CGST Act. The supplier issues a credit note under Section 34(1) when the original invoice charged too much: goods are returned, a service falls short, or a discount is agreed after the sale. The supplier issues a debit note under Section 34(3) when the invoice charged too little and the value or tax has to go up. Both are always raised by the supplier, never the buyer. A credit note reduces the supplier's output tax, but only if it is declared in a GST return by 30 November following the end of the financial year of the original supply, or the annual return, whichever is earlier, under Section 34(2). A debit note carries no such issue deadline, and the buyer's credit on it is timed to the debit note's own date under Section 16(4).

In this section
Myth

If I overcharged a customer, I can just hand back the money or pass an accounting credit note.

Fact

To reduce your GST liability you must issue a tax credit note under Section 34(1) of the CGST Act. A plain accounting credit note does not reverse the tax, and the GST credit note has a hard deadline.

What is a credit note under GST?

Short answer

A document the supplier issues under Section 34(1) when the original tax invoice charged too much, so the taxable value or tax has to come down.

  • Triggers: goods returned, a deficient supply, a price reduction, or a post-sale discount that meets Section 15(3).
  • Effect: it reduces the supplier's output tax, and correspondingly the buyer reverses that much input tax credit.
  • It is always issued by the supplier, never raised by the buyer.
  • Why it matters: only a tax credit note reported in your GST return cuts your liability; an accounting credit in your books does nothing for GST.

What is a debit note under GST?

Short answer

A document the supplier issues under Section 34(3) when the original invoice charged too little, so the taxable value or tax has to go up.

  • Triggers: an undercharged invoice, a later price increase, or a short-levy of tax found after billing.
  • Effect: it raises the supplier's output tax, and lets the buyer claim the extra input tax credit.
  • A supplementary invoice does the same job and is treated as a debit note.
  • Why it matters: issuing a debit note is how you fix an undercharge without cancelling and reissuing the whole invoice.

Credit note or debit note: which do you issue?

Short answer

Both are issued by the supplier. Charged too much, issue a credit note; charged too little, issue a debit note. Both are reported in GSTR-1 and flow to the buyer's GSTR-2B.

SituationDocumentDirection of taxStatute
Goods returned, deficiency, or post-sale discountCredit noteSupplier's output tax goes downSection 34(1)
Undercharge or later price increaseDebit noteSupplier's output tax goes upSection 34(3)
Buyer wants a correctionBuyer asks the supplier; never self-issuedDepends on the correctionSection 34

Source: Section 34, CGST Act. Both notes must reference the original invoice. A note that reverses tax is different from cancelling an e-invoice; see what an IRN is.

What is the time limit to issue a GST credit note?

Short answer

A credit note must be declared in a return by 30 November following the end of the financial year of the original supply, or the annual return date, whichever is earlier, under Section 34(2). A debit note has no such issue deadline.

Miss that window and the credit note no longer reduces your output tax, so an unbilled return or discount becomes your cost. A debit note is treated differently: there is no deadline to raise it, and the buyer's input tax credit on it runs from the debit note's own financial year under Section 16(4), not the original invoice date. The deadline is tied to the financial year of the supply, so check the exact cut-off for the year you are correcting.