The recent decision of Yorkwest Plumbing Supply Inc. v. The Queen (2020 TCC 122) demonstrates the court’s reluctance to embrace an accounting remedy as an alternative to amending previously filed returns in the manner prescribed by law. The company in this case was unfortunate as it probably paid double tax than it should. However, the corporation’s management team didn’t deal with this issue accurately in the first place and correctly when they realized there was an understatement of the cost of inventory. In tax law, timing matters. Taxpayers and their preparers need to exercise extreme caution when taking accounting adjustment entries, especially when the amounts concerned are material. Even these entries may be permitted under GAAP, do not assume it would be permitted automatically for tax purpose.