The Appellate Division reversed the New York State Tax Appeals Tribunal decision, which found that the retroactive application was not significant enough to violate the Due Process Clause. While it recognized that the retroactivity period was relatively brief, the Appellate Division held that no public purpose was served by the retroactive application of the law (citing James Sq. Assoc. LP v. Mullen (21 NY3d 233, 249-250 [N.Y. 2013]). Further, the Appellate Division held that the taxpayer reasonably relied on the old law and did not have adequate warning of the law change. The Appellate Division made clear that the requirement for “adequate warning” was not eliminated because the taxpayer could not have taken action to avoid the law. The Appellate Division pointed out that with adequate warning the Petitioner could have changed its behavior in conducting its business (i.e., investment in business versus retain cash assets).
The Due Process constraints on retroactive application of tax laws is critically important in light of recent developments following the U.S. Supreme Court Decision in South Dakota v. Wayfair (radically expanding state taxing jurisdiction) and state tax conformity to the federal Tax Cuts and Jobs Act.