Quick answer: a GST credit note is issued by the supplier when the taxable value or tax on an invoice turns out to be higher than it should be, for example when goods are returned, the rate was wrong or the customer rejected a service. It reduces your output tax and the buyer's input tax credit. It must be reported by 30 November after the financial year of the original invoice, or by the annual return date if earlier.
When you can issue a GST credit note
Section 34 allows a credit note when:
- The taxable value on the invoice is more than the actual value of the supply
- The tax charged is more than the tax payable
- Goods are returned by the buyer
- Services are found deficient or rejected
- A discount agreed before or at the time of sale, and linked to specific invoices, is given later
What you cannot do is reduce your GST with a credit note if the tax has already been passed on to someone else. In that case the output tax stays as it is.
Beautiful GST invoices with your signature and stamp, quotations to credit notes, inventory, UPI collection and 30+ reports.
Start free See the demoFields a credit note must contain
| Field | Why it matters |
|---|---|
| Supplier name, address, GSTIN | Identifies who is reducing tax |
| Document title "Credit Note" | So it is not mistaken for an invoice |
| Serial number (up to 16 characters) and date | Separate series from invoices is best |
| Recipient name, address, GSTIN or UIN | Links it to the buyer's ITC |
| For unregistered buyers: name, delivery address, state name and code | Place of supply |
| Original invoice number(s) and date(s) | Required, and it fixes the deadline |
| Taxable value, tax rate, tax amount credited | The actual reduction |
| Signature or digital signature | Authentication |
If you are covered by e-invoicing, credit notes are also reported to the IRP and carry an IRN, just like invoices.
The 30 November deadline, explained with dates
The deadline depends on the date of the original invoice, not the date of the credit note.
| Original invoice date | Report credit note no later than |
|---|---|
| Any date in FY 2025-26 (April 2025 to March 2026) | 30 November 2026, or annual return filing if earlier |
| Any date in FY 2026-27 | 30 November 2027, or annual return filing if earlier |
A return received in December 2026 against a sale from February 2026 has missed the window. You can still give the customer money back through a commercial credit note, but your GST does not come down.
How it shows up in returns
- Your side: report the credit note in GSTR-1 for the month you issue it. Output tax in GSTR-3B falls by the tax on it.
- Buyer's side: the credit note appears in their auto-drafted statement, and their ITC for the invoice is reduced.
- Unregistered buyers: amend the B2C figures for the relevant state and rate.
Credit note or debit note?
| Credit note | Debit note | |
|---|---|---|
| Issued when | Value or tax was too high | Value or tax was too low |
| Effect on supplier's tax | Decreases | Increases |
| Typical cause | Return, overbilling, agreed discount | Undercharged price, extra freight added later |
| Time limit | 30 November rule | Also tied to 30 November following the FY of the debit note |
A sample credit note
CN/26-27/0021 · 12 Sep 2026 · Supplier: Kaveri Electricals, GSTIN 29XXXXX · Buyer: Sunrise Traders, GSTIN 29XXXXX · Against invoice INV/26-27/0318 dated 28 Aug 2026 · Reason: 20 nos MCB 32A returned, damaged in transit · Taxable value ₹9,000 · CGST 9% ₹810 · SGST 9% ₹810 · Total credit ₹10,620.
Keeping it clean in practice
- Never edit an old invoice to fix a mistake. Issue a credit note and, if needed, a fresh invoice.
- Use a separate number series such as CN/26-27/.
- Always choose the original invoice from a list instead of typing its number.
- Put a reminder in October to clear pending returns and discounts before the 30 November cut-off.
In MizUp Finance, you raise a credit note from the invoice itself, so the buyer, GSTIN, items and tax rates carry over and the invoice balance updates straight away.
Frequently asked questions
What is the time limit for a GST credit note?
A credit note must be declared in the return for a month no later than 30 November following the end of the financial year of the original invoice, or the date you file the annual return, whichever comes first.
Can one credit note cover several invoices?
Yes. A single credit note can be issued against multiple invoices from the same financial year, as long as you list each invoice number and date.
What is a commercial or financial credit note?
A credit note that reduces the amount the customer owes but does not reduce GST. It is used for discounts not agreed before the sale, or after the GST deadline has passed.
Does the buyer need to reverse input tax credit?
Yes. When a GST credit note is issued, the buyer's eligible ITC falls by the tax on the credit note, and it shows in their records once you report it.
