In Adani Power Ltd. v. Union of India, the Supreme Court of India reaffirmed the doctrine of stare decisis, holding that law cannot fluctuate with a change in judicial composition. Adani Power, operating within a Gujarat SEZ, supplied electricity to the Domestic Tariff Area. In 2015, a Division Bench of the Gujarat High Court struck down the levy of customs duty on such supply as unconstitutional; the decision attained finality after Supreme Court affirmation. However, a 2019 coordinate bench refused to extend the benefit for later periods, prompting the appeal. The Supreme Court held that a coordinate bench is bound by an earlier decision of equal strength and cannot dilute or disregard it; any disagreement must be referred to a larger bench. It further ruled that exemption notifications under Section 25 of the Customs Act cannot be used to impose a tax, especially absent a charging provision electricity generated domestically is not an “import.” Once a levy is declared ultra vires, subsequent notifications perpetuating it are invalid. The Court set aside the 2019 judgment and directed refunds for 2010–2016 collections (without interest).