Retrospective Relief: Bombay High Court Rules GST Refund Formula Amendments are Curative, Overruling Prospective Limitations to Fix Inverted Duty Structure Anomalies.
In the intricate world of indirect taxation, the "inverted duty structure" has long been a thorn in the side of manufacturers and service providers. This occurs when the tax rate on inputs is higher than the tax rate on the finished output, leading to a persistent accumulation of Input Tax Credit (ITC) that cannot be fully utilized. While the law provides for refunds in such cases, the mathematical formula used to calculate these refunds has been a battleground for years. A recent landmark judgment by the Bombay High Court in CHEC-TPL Line 4 Joint Venture v. Union of India has finally cleared the air, offering a masterclass on when a change in tax law can—and must—act retrospectively.
The "Curative" Power of AmendmentsThe most significant takeaway from this judgment is the court's characterization of the 2022 amendment to Rule 89(5) of the CGST Rules. Usually, tax laws are presumed to be prospective unless stated otherwise. However, the court held that when an amendment is introduced to fix an "anomaly" or a "skewed" result that unfairly favored the revenue, it is curative in nature. Because it is curative, it must be applied retrospectively to all pending or eligible claims, regardless of whether the tax period predates the amendment.
The Supreme Court’s "Urge" as a MandateThe history of this dispute is fascinating. In the earlier VKC Footsteps case, the Supreme Court upheld the validity of the old, flawed formula but explicitly "urged" the GST Council to reconsider it because it led to inequitable results. The Bombay High Court observed that the subsequent amendment was a direct response to this judicial nudge.
"The amendment made by Notification No. 14/2022 was clarificatory, as per the decision of GST Council issued pursuant to the direction issued by the Supreme Court... to remove the anomaly in the formula."This highlights a unique dialogue between the judiciary and the executive where a court’s suggestion can transform into a binding curative legislative action. Rejecting the "Prospective" Shield of the Revenue
The tax authorities relied heavily on a Circular (No. 181/2022) which claimed the new formula would only apply to refund applications filed after July 5, 2022. The High Court dismantled this argument, stating that a Circular cannot override the fundamental legal character of a curative amendment. If the amendment exists to provide a "reasonable interpretation" and remedy "unintended consequences," the date of the application becomes secondary to the right to a fair calculation.
The End of Revenue Bias in Inverted Duty CalculationsThe core of the dispute was how the formula treated the "tax payable" on the output. The old formula assumed that the entire output tax was paid using ITC from inputs alone, ignoring the ITC from input services. This skewed the math in favor of the government. The court affirmed that the new formula, which recognizes the proportional utilization of both inputs and input services, is the only way to achieve "harmony" in the tax structure.
"The numerator and denominator are made in harmony which was not the position prior to the amendment which had resulted anomaly in the formula."A Victory for Consistency Across High Courts
Finally, this judgment reinforces the principle of judicial comity. The Bombay High Court chose to follow the path set by the Gujarat High Court in the Ascent Meditech case, which had already been tested and left undisturbed by the Supreme Court. By aligning its view, the court has ensured a uniform tax environment for businesses operating across different states, preventing a fragmented legal landscape where taxpayers in one state are treated differently than those in another for the same federal tax.
This ruling is a powerful reminder that while the government has the power to draft tax formulas, those formulas must remain grounded in logic and equity. When they fail, and the legislature steps in to fix them, the benefits of that "fix" should reach back to those who suffered under the broken system.
Case: CHEC TPL LINE 4 JOINT VENTURE v. UNION OF INDIA AND ORS
Law: Central Goods and Services Tax Act, Constitution of India.
Citation: 2026:BHC-AS:19606-DB
Decision Date: 23-04-2026