Post-sale discounts have long been a practical challenge under GST because the law earlier required them to be agreed in advance and linked to specific invoices. The Finance Act, 2026 has now simplified this position by removing the pre-existing agreement requirement, making the treatment of genuine commercial discounts much easier for businesses to manage.

Why this matters

In many industries, discounts are not decided at the time of supply. They are often settled later based on annual turnover, quarterly performance, market conditions, stock movement, or dealer relationships. Under the earlier rule, many businesses were forced to issue only commercial credit notes or avoid claiming GST adjustment altogether, which created avoidable tax and compliance friction.

The amended law now better reflects how trade actually works. Businesses can structure post-sale discounts with less litigation risk, provided the credit note mechanism and ITC reversal requirements are followed correctly.

Earlier GST position

Before the amendment, Section 15(3)(b) of the CGST Act allowed a post-sale discount to reduce taxable value only if the discount had been agreed at or before the time of supply and could be linked to the relevant invoice. If these conditions were not met, the supplier could not reduce output tax through a GST credit note.

As a result, many businesses used financial or commercial credit notes instead of GST credit notes. In those cases, the original taxable value and GST liability remained unchanged, and the recipient generally did not reverse ITC because there was no GST adjustment on the supply itself.

Changes under Finance Act, 2026

The Finance Act, 2026 has removed the old barrier that required a prior agreement for post-sale discounts. The amended framework now permits a post-sale discount to be adjusted through a GST credit note even if the discount was not pre-agreed at the time of supply.

The corresponding amendment to Section 34 also makes the credit note route clearer for discounts covered under Section 15(3)(b). In practical terms, this means a genuine retrospective discount can now be reflected under GST without forcing businesses into artificial documentation structures.

Tax treatment after the amendment

Where a supplier issues a GST credit note for a post-sale discount, the supplier can reduce output tax accordingly, subject to the credit note being issued within the prescribed time limit. The recipient must reverse the proportionate ITC attributable to the discount amount.

This keeps the tax chain balanced. The supplier’s tax liability comes down only when the recipient also reduces the credit claimed on the original invoice. That is now the core compliance requirement, rather than proof of a pre-existing discount agreement.

Commercial credit notes still matter

Not every payment after the sale will qualify as a post-sale discount. If the amount is actually consideration for a separate supply, such as marketing support, product display, promotional activity, or other services, GST may apply as a separate transaction.

The distinction between a real price reduction and payment for services remains important. Businesses should therefore document the commercial basis of each adjustment carefully, especially in distributor-led schemes or incentive arrangements.

Compliance points to watch

The amendment simplifies the law, but it does not eliminate compliance. Suppliers should still ensure that credit notes are properly issued and reported in GST returns, and recipients should reverse the related ITC in the correct tax period.

Businesses should also preserve internal records showing how the discount was computed and why it was allowed. Even though a pre-supply agreement is no longer mandatory, audit support will still depend on clear commercial documentation.

Practical impact for businesses

This change is especially useful for FMCG, pharma, manufacturing, and trading businesses that frequently run volume-based rebates, year-end schemes, and performance-linked incentives. It reduces friction where discounts are determined after the original supply has already taken place.

It also helps align GST practice with real-world commercial arrangements, where pricing often evolves over time rather than being fixed in advance. That should reduce disputes and make post-sale discount administration more workable.

Conclusion

The Finance Act, 2026 has made post-sale discounts under GST significantly simpler by removing the pre-agreement condition. Going forward, the key test is not whether the discount was agreed before supply, but whether the credit note is validly issued and the recipient reverses the corresponding ITC.

For businesses, this is a welcome shift toward commercial reality, but the success of the new regime will depend on disciplined documentation and return compliance.

If you’d like expert support to streamline your GST compliance and minimise audit exposure, get in touch with our team.