General information, not professional advice. GST rules, rates and due dates change by notification. Check the current position on the GST Portal or with your CA before you act on anything here.
The short version
- Credit note: the value or tax of the original invoice goes down, or goods come back. Debit note: it goes up.
- A credit note reduces your output tax only if it is declared by 30 November following the financial year, or before the annual return, whichever is earlier.
- A debit note has no such deadline, because it increases tax.
- Both are reported in GSTR-1, as CDNR against a registered buyer and CDNUR against an unregistered one.
- Your buyer has to reverse the credit on a credit note, which is why they notice when you raise one.
Which note, and when
The test is direction. If the taxable value or the tax charged on an invoice turns out to be more than it should be, you raise a credit note. If it turns out to be less, you raise a debit note. Nothing else changes the original invoice.
Common credit-note cases: goods returned, goods rejected or short-received, a post-sale discount agreed in the contract, a rate applied wrongly upwards, a deficiency in the service supplied. Common debit-note cases: a rate applied wrongly downwards, an undercharge, extra goods delivered against the same invoice.
What the note must contain
- The words "credit note" or "debit note" on the face of it
- Your name, address and GSTIN
- A serial number, again at most 16 characters, unique for the year and consecutive, in its own series
- The date of issue
- The recipient's name, address and GSTIN if registered
- The serial number and date of the original invoice
- The taxable value, the rate and the amount of tax being credited or debited
- Signature or digital signature
The link back to the original invoice is what makes the note usable, so a note that says "against various bills" is a note your buyer's CA will come back about.
The November deadline
A credit note reduces the tax you already declared, so the law limits how long you may look back. You must declare it in a return by 30 November following the end of that financial year, or the date of filing the annual return for that year, whichever is earlier. Miss it and you can still issue a commercial credit note to settle the money, but you cannot reduce your GST liability with it.
A debit note has no equivalent cut-off. It increases tax, so the department is in no hurry to stop you.
What happens to the tax
A credit note reverses output tax in your books in the month you issue it. Your buyer, on their side, has to reverse the input tax credit they took on the original invoice. That reversal is the reason a credit note is a conversation, not a silent adjustment: it moves money on both sides.
A debit note adds output tax for you and, subject to the usual conditions, credit for the buyer.
How they appear in GSTR-1
Both go into the return for the period in which they are issued. Against a registered buyer they are reported as CDNR with the buyer's GSTIN; against an unregistered buyer they are CDNUR. The original invoice number and date travel with them, which is how the portal ties the two together and how the amount lands in your buyer's GSTR-2B.
Sales returns in practice
A return is rarely just paperwork. Stock comes back and has to go into inventory at the right cost, the customer's balance has to change, the output tax has to reverse, and the credit note has to be numbered and reported. Done by hand in four places, this is where a month-end stops balancing.
How AawazAI handles a return
You say "Mehta Traders ne do peti wapas ki". The app proposes a customer return: the items go back into stock at their cost, the customer's balance drops, a credit note is minted against the original invoice with the output tax reversed, and the note is carried into your GSTR-1 summary as CDNR or CDNUR. You confirm the card first, and the correction posts as a reversal rather than an edit, so the original sale and the return both remain visible in the books.
Returns that reverse themselves properly
Say the return and AawazAI puts the stock back, drops the customer balance, mints the credit note against the original invoice and reverses the output tax, all from one confirmation.
Frequently asked questions
What is the time limit for a credit note under GST?
It must be declared in a return by 30 November following the end of the financial year in which the original supply was made, or the date of filing the annual return for that year, whichever is earlier. After that you can still issue a commercial credit note, but it cannot reduce your GST liability.
Is there a time limit for a debit note?
No. A debit note increases the tax payable, so there is no cut-off for issuing one. It is reported in the return for the period in which it is issued.
Can one credit note cover several invoices?
A consolidated credit note is permitted in some circumstances, but linking each note to one original invoice is far easier to defend and far easier for your buyer to reconcile. If you do consolidate, keep the working that shows which invoices it covers.
Does my buyer have to do anything when I raise a credit note?
Yes. They reverse the input tax credit they claimed on the original invoice, to the extent of the credit note. This is why the note should reach them promptly and reference the original invoice clearly.
What is the difference between a credit note and a refund voucher?
A credit note adjusts an invoice that was already issued. A refund voucher is issued when you return an advance you had received against a supply that did not happen, and it references the receipt voucher rather than an invoice.