GST Debit Note vs Credit Note: When a Supplier Issues Each

Both documents correct an invoice that has already been issued. The difference is the direction of the correction. A debit note increases what the party owes and the tax the supplier must pay. A credit note reduces what the party owes and, where the conditions are met, the tax the supplier must pay.

In GST, these are supplier documents. The supplier who issued the original tax invoice is the one who issues the debit note or credit note. A buyer may raise its own internal note to record a claim against a supplier, but that internal note does not replace the supplier's GST document. Section 34 of the CGST Act places both notes with the registered person who made the supply, and the CGST Rules set out what each note must contain.

Issue a debit note when the original invoice understated the amount. The principle is simple: the correct value of the supply, or the correct tax on it, is higher than what was billed.

• ✓The invoice was raised at a lower price than the agreed contract price.
• ✓A price revision agreed under the contract applies to supplies already invoiced.
• ✓Quantity actually supplied was more than the quantity billed.
• ✓Tax was charged at a lower amount than applicable on the supply.
• ✓Additional charges that form part of the value of supply, such as agreed freight or packing, were left out of the invoice.

Do not use a debit note to bill a new, separate supply. A fresh supply needs its own tax invoice. A debit note only corrects the value or tax of a supply already invoiced.

Issue a credit note when the original invoice overstated the amount, or when the supply did not happen the way it was billed. The correct value or tax is lower than what was invoiced.

• ✓The customer returned some or all of the goods.
• ✓Goods or services were found deficient and the party agreed to a reduced amount.
• ✓The invoice was raised at a higher price or quantity than agreed.
• ✓Tax was charged at a higher amount than applicable.
• ✓A post-supply discount was agreed in advance and is linked to the specific invoices, where the conditions for reducing value are met.

If the credit note leads to money going back to the customer, the refund itself needs its own approval and reporting steps. Our guide on reporting a GST credit note and customer refund walks through that side.

Use this table as a first check. It states the principle only. The exact return fields, any conditions and any time limits change from time to time, so confirm the current position on the GST portal or with your CA.

In practice, both notes appear in the supplier's outward supply statement, and the net effect flows into the summary return where tax is paid. If you are unsure which return carries what, our GSTR-1 vs GSTR-3B checklist for small businesses explains how the two fit together.

All figures below are illustrative only and use an assumed tax amount for arithmetic. They are not a statement of any actual GST rate.

In this illustration, the supplier first under-billed the price, so it issues a debit note for the difference on all 100 units. Later, the party returns 10 units, so the supplier issues a credit note at the corrected price. Each note references the original invoice. In the next return, the supplier reports both notes; the customer's credit moves up with the debit note and down with the credit note, ending at the net tax shown.

• ✓Supplier name, address and GSTIN.
• ✓A clear label: debit note or credit note.
• ✓A unique serial number and the date of issue.
• ✓Customer name, address and GSTIN where registered.
• ✓The original invoice number and date it relates to.
• ✓The taxable value and tax being increased or reduced.
• ✓Signature or digital signature of the supplier or authorised person.

This list follows the particulars set out in the CGST Rules, which also require the rate of tax and a serial number that is unique for the financial year. Confirm the current required fields with your CA, and keep the note series separate from your invoice series. Our GST invoice checklist for service businesses covers the related invoice fields.

• Raising a debit note for a brand-new supply instead of a fresh tax invoice.
• Issuing a credit note without referencing the original invoice.
• Reducing GST on a commercial discount that does not meet the conditions for a value reduction.
• Letting the buyer's internal debit note stand in for the supplier's credit note.
• Recording the note in the books but leaving it out of the return.
• Not telling the customer, so their input tax credit does not match your filing.
• Cancelling and reissuing an invoice already reported, instead of using a note.

When this does not apply: errors in identity details, such as the wrong GSTIN or place of supply, are corrected differently from value changes. Notes issued under reverse charge, exports and cases involving cancelled registrations also need separate review. Time limits for issuing and reporting notes exist, so check the current position on the GST portal or with your CA before acting on an older invoice.