According to the Constitution Bench in Commissioner of Income-tax v. Vatika Township (P) Ltd (2014),…

Vatika Township (2014) restated that unless a contrary intention appears, legislation is presumed not to be retrospective. It recognised an exception where legislation "confers a benefit on some persons but without inflicting a corresponding detriment" on others. New tax burdens, new offences and the loss of accrued rights are exactly what the presumption guards against.