A dealer calls on 20 November. The manufacturer has cut its price, and the dealer wants ₹15 a unit back on the 300 units still sitting in their godown. You billed those goods in September with GST. Can you issue a credit note that also reduces your GST? From 1 November 2026, usually yes, provided the dealer reverses the matching input tax credit.
That answer is new. Until 31 October 2026, a price cut agreed after the sale cannot reduce GST unless the discount was agreed before or at the time of supply and linked to specific invoices. Most suppliers issue a “commercial” credit note with no tax in it and move on. This guide explains which rate difference credit notes carry GST, how the 1 November change works, and how to report them without your dealer’s IMS undoing your work.
What is a rate difference credit note under GST?
A rate difference credit note is a credit note you issue because the price on the original tax invoice turned out to be higher than what the buyer finally pays. In practice it covers two very different situations, and GST treats them under different provisions:
Billing error. You agreed ₹240 a unit and the invoice said ₹250. The taxable value on the invoice simply exceeds the correct value.
Price revision after the sale. The invoice was right when issued, but later you agreed to reduce the price: price protection on unsold stock, a market fall, a volume rebate earned later in the year.
The first has always been covered by section 34(1) of the CGST Act, which allows a credit note where the taxable value or tax charged in an invoice exceeds what is payable. The second is a post-supply discount, and that is where the law is changing.
What changed for post-sale discounts on 1 November 2026?
Sections 153 and 154 of the Finance Act, 2026 amend sections 15(3)(b) and 34(1) of the CGST Act. Notification No. 03/2026–Central Tax dated 26 October 2026 brings them into force from 1 November 2026.
After the amendment, a discount given after the supply is excluded from the taxable value if two things happen: the supplier issues a credit note for it, and the recipient reverses the input tax credit attributable to that discount, in line with section 34. The old conditions, a discount agreement entered into on or before the supply and a link to specific invoices, are gone. Section 34(1) now also names a section 15(3)(b) discount as a ground for issuing a credit note.
Two open points remain, and we would not guess at either. Commentators have not settled how the new rule applies to discounts relating to supplies made before 1 November 2026, and the CGST Rules and forms had not been amended when we checked. If a large credit note relates to old supplies, take a view with your CA before issuing it with GST.
Which rate differences carry GST and which do not?
Situation | GST credit note allowed? | Basis | What the buyer must do |
|---|---|---|---|
Invoice rate higher than the agreed rate (billing error) | Yes | Section 34(1), excess taxable value | Reverse the ITC on the excess |
Price cut agreed after the sale, credit note issued on or after 1 Nov 2026 | Yes, if the buyer reverses ITC | Section 15(3)(b) read with section 34(1), as amended | Reverse the ITC attributable to the discount |
Price cut agreed after the sale, credit note issued before 1 Nov 2026 without a prior agreement | No, commercial credit note only | Old section 15(3)(b) | Nothing under GST; ITC stays as claimed |
Invoice rate lower than the agreed rate | No, issue a debit note instead | Section 34(3) | Claim ITC on the debit note |
Any credit note issued after the time limit | No GST reduction | Section 34(2) | Treat as a commercial adjustment |
Commercial credit notes are still allowed. They settle the money between you and the buyer but leave the GST on the original invoice untouched, so neither side adjusts tax.
A worked example: one invoice, two credit notes
Say you run an electrical fittings distributorship in Rajkot. On 12 September 2026 you sell 400 units to a dealer in the same state at ₹250 each. Assume the goods carry 18% GST.
Taxable value: 400 × ₹250 = ₹1,00,000
CGST 9% ₹9,000 + SGST 9% ₹9,000 = ₹18,000
Invoice total: ₹1,18,000
Credit note 1, billing error. On 3 October the dealer points out that the rate agreed on the purchase order was ₹240. The excess is 400 × ₹10 = ₹4,000. GST on it is ₹720 (CGST ₹360, SGST ₹360). You issue a credit note for ₹4,720 under section 34(1). This was valid before the amendment and remains valid now.
Credit note 2, price protection. On 20 November the manufacturer cuts its price and you agree to pass ₹15 a unit to the dealer on 300 unsold units. Discount: 300 × ₹15 = ₹4,500. GST on it: 18% of ₹4,500 = ₹810 (CGST ₹405, SGST ₹405). Credit note total: ₹5,310.
Because it is issued after 1 November 2026, this credit note can carry GST even though nothing was agreed in September. Your output tax falls by ₹810 only if the dealer reverses ₹810 of ITC. Had you issued the same note on 25 October, it would have been a ₹4,500 commercial credit note with no GST in it.
Net effect on the original sale: taxable value ₹1,00,000 − ₹4,000 − ₹4,500 = ₹91,500, and GST ₹18,000 − ₹720 − ₹810 = ₹16,470, which is 18% of ₹91,500.
What is the time limit for issuing a GST credit note?
Section 34(2) sets the outer limit. A credit note that reduces GST must be declared in the return for the month it is issued, and no later than 30 November following the end of the financial year in which the supply was made, or the date you file the annual return for that year, whichever is earlier.
For the September 2026 sale above, that means 30 November 2027 at the latest, or earlier if you file the FY 2026-27 annual return before then. The new post-sale discount rule does not extend this. A price protection claim that arrives in December 2027 for a September 2026 invoice can only be settled through a commercial credit note.
How do you report a rate difference credit note in GSTR-1?
Report it in GSTR-1 for the month in which you issue it, not the month of the original invoice. Credit notes go in the credit and debit notes section of GSTR-1, with notes to registered buyers reported separately from those to unregistered buyers. If you are required to issue e-invoices, a credit note is also a document that needs an IRN.
Under Rule 53(1A) of the CGST Rules, the credit note should carry:
Your name, address and GSTIN, and the words identifying it as a credit note
A consecutive serial number of up to 16 characters and the date of issue
The buyer’s name, address and GSTIN
The serial number and date of the original tax invoice
The taxable value, rate and amount of tax being credited
Your signature or digital signature
The amended section 15(3)(b) no longer needs the discount itself to be linked to specific invoices, but Rule 53 still asks for the corresponding invoice details. Until the rules catch up, keep quoting the original invoice where you can. For price protection on stock bought across several invoices, list each one with the quantity covered.
What does the buyer see in IMS, and why does it matter to you?
Your output tax reduction now depends on the buyer. The proviso to section 34(2) says the supplier gets no reduction in output tax if the ITC attributable to the credit note, where availed, has not been reversed by a registered recipient. For unregistered buyers, the test is whether the tax has been passed on to someone else.
The GST portal enforces this through the Invoice Management System. From the October 2025 tax period, according to GSTN’s FAQ on the IMS changes, the buyer can act on your credit note in three ways:
Accept. The buyer’s ITC is reduced in GSTR-2B. The buyer can declare a full or partial reversal, or none if no ITC was claimed.
Reject. The buyer keeps the ITC, and the GST on your credit note is added back to your liability.
Pending. The decision is deferred for one tax period (one quarter for quarterly filers). If the buyer still does nothing, the credit note is treated as accepted.
We covered the buyer’s side in detail in our guide to accepting, rejecting or keeping invoices pending in IMS. For you as the supplier, the lesson is simple. Before you issue a GST credit note for a post-sale discount, get the buyer to confirm in writing that they will accept it in IMS. A rejected ₹810 is ₹810 back on your GSTR-3B.
A short routine for rate difference credit notes
Decide which case you are in: billing error, post-sale discount, or upward revision needing a debit note.
For a discount, check the date. Issued on or after 1 November 2026 it can carry GST; for supplies made before that date, take a view first.
Check the section 34(2) deadline against the original invoice date.
Get the buyer’s written agreement on the amount and their ITC reversal.
Issue the credit note with the Rule 53 details, and generate the IRN if you are on e-invoicing.
Report it in that month’s GSTR-1, then watch whether it is rejected before you file GSTR-3B.
Where hisabkitab fits in
The work in a rate difference credit note is mostly bookkeeping: finding the right original invoices, getting the tax split right and making sure it reaches the correct month’s return. In hisabkitab you raise the credit note from your GST invoicing records, and it flows into the GSTR-1 data you file from the GST module. If you issue e-invoices, the e-invoicing tools generate the IRN and QR code for the note in the same place.
On the buying side, GSTR-2B reconciliation flags credit notes from your suppliers that do not match your books, so you reverse the right ITC instead of discovering the gap in a notice.
Frequently asked questions
Can I issue a GST credit note for a discount that was not agreed before the sale?
From 1 November 2026, yes. The amended section 15(3)(b) only needs a credit note from you and an ITC reversal by the buyer. Before that date, such discounts needed a prior agreement linked to specific invoices.
Is a rate difference credit note the same as a commercial credit note?
No. A GST credit note reduces the taxable value and the tax on the original supply. A commercial credit note only settles the price between the parties and leaves GST untouched.
What happens if my buyer rejects the credit note in IMS?
The buyer keeps the ITC, and the tax on the credit note is added back to your liability. You will need to settle the dispute with the buyer and, if it is resolved, the buyer can act on the record as the portal allows.
Which month do I report a credit note in GSTR-1?
The month in which you issue it, not the month of the original invoice.
Can I issue a credit note after 30 November?
Not one that reduces GST for a supply made in the previous financial year. Section 34(2) caps it at 30 November following the year of supply, or the annual return date if earlier.
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