This article provides a case analysis of Bank of Montreal v. Duguid, discussing the concept of undue influence in business law. The case involves a defendant who signed a loan under the persuasion of her husband and later claimed undue influence. The article explores the court's decision and the principles surrounding the presumption of undue influence. It also compares the case to similar cases and discusses the responsibilities of creditors in avoiding issues of constructive notice. Overall, the article supports the court's decision and highlights the importance of ensuring informed consent in financial transactions.