Author Margaret Nixon, of Stikeman Elliott LLP, reviews the recent decision of the Tax Court of Canada in Prairielane Holdings Ltd. v. The Queen, 2019 TCC 157. In this case, the Court considers the deemed association rule in subsection 256(2.1) of the Income Tax Act and provides useful guidance on the legal principles that are applicable in determining whether one of the main reasons for the separate existence of two or more corporations is the reduction of tax.