Executive Summary: Key Legal and Evidentiary Issues

• Whether the Tax Court erred in finding that the normal assessment period for Mr. Siam's 2016 tax year ended on April 19, 2021 was the central question on appeal.
• Subsection 152(3.1) placed the burden on Mr. Siam to prove, on a balance of probabilities, that the 2018 notice of assessment was never sent.
• The Mpamugo framework governed how his allegation that the notice was not mailed had to be tested.
• Credibility was assessed at the first step of that framework, where the Tax Court found that evidence not credible.
• A palpable and overriding error was required before the Court of Appeal could disturb the Tax Court's weighing of the evidence.
• Mr. Siam's procedural fairness argument rested on incorrect CRA advice that he could object to the reassessment.

Facts of the case

Mohamed Siam appealed to the Federal Court of Appeal from a decision of the Tax Court of Canada (2025 TCC 69) that had granted the Crown's motion to quash his appeal. The underlying dispute concerned a notice of reassessment dated August 18, 2023 for his 2016 tax year (the 2023 Reassessment). The Tax Court held that the appeal could not proceed because Mr. Siam's notice of objection was invalid: the 2023 Reassessment had been issued after the normal assessment period had ended and under subsection 152(4.2) of the Income Tax Act, R.S.C. 1985, c. 1 (5th Supp.), and subsection 165(1.2) prohibits objections to reassessments of that kind. The Tax Court reasoned that the normal assessment period had ended on April 19, 2021 — three years after the April 19, 2018 notice of assessment (the 2018 Assessment) for the same tax year — so the 2023 Reassessment, issued nearly two years later, fell within subsection 152(4.2). Mr. Siam's position was that he did not receive the 2018 Assessment until a later date, meaning the normal assessment period never began in 2018 and subsection 152(4.2) did not apply.

Statutory provisions at issue

This is a tax matter rather than a contract or insurance dispute, so the provisions in issue are statutory rather than contractual. Subsection 152(4.2) allows the Minister to reassess where a taxpayer applies for a refund or reduction of tax within 10 years after the end of the relevant tax year. Subsection 165(1.2) bars a taxpayer from objecting to such a reassessment. Subsection 152(3.1) provides that the normal assessment period begins with the sending of a notice of an original assessment, and it placed on Mr. Siam the burden of establishing, on a balance of probabilities, that the 2018 Assessment was not sent. The framework for testing an allegation that a notice was not sent came from Mpamugo v. The Queen (2016 TCC 215, aff'd 2017 FCA 136): a taxpayer must first assert either that he did not receive the notice and therefore believes it was not mailed, or that it was mailed to the wrong address through no fault of his own and so was, in effect, not mailed. The Tax Court may assess the taxpayer's credibility on that point, provided it does so after all the evidence has been heard.

The court's reasoning and analysis

The appeal turned on whether the Tax Court erred in finding that the normal assessment period ended on April 19, 2021. Because Mr. Siam's argument was essentially a challenge to how the Tax Court weighed the evidence, the Court of Appeal could intervene only on a showing of palpable and overriding error — an error that is both obvious and goes to the very core of the outcome (citing Housen v. Nikolaisen, 2002 SCC 33, and Benhaim v. St-Germain, 2016 SCC 48). The Court found no such error. It was not persuaded by the submission that, because the Crown's affiant said the 2018 Assessment was "issued" rather than confirming it was "mailed," the date of mailing was too uncertain to presume; the wording of the affidavit and of the 2023 Reassessment did not establish that the Tax Court erred in applying the presumption. The Court likewise rejected the claim that the Tax Court misapplied Mpamugo by discounting Mr. Siam's evidence and reaching a credibility finding before fully assessing the record. The Tax Court appropriately assessed credibility at the first step of the test, was not satisfied that Mr. Siam had met his burden there, and was not required to continue to the later steps. The Court saw no difficulty in the conclusion that Mr. Siam was likely aware of the 2018 Assessment in 2019 at the latest, which was enough to support the finding that the normal assessment period had ended by 2023. Finally, the Court addressed the procedural fairness argument — that both the CRA officer handling his file and the 2023 Reassessment indicated he could object, giving him a legitimate expectation that he could appeal. That argument failed because the doctrine of legitimate expectations protects only procedural rights (citing Baker, Agraira, and Moreau-Bérubé). Although the Court acknowledged it was unfortunate that Mr. Siam was given incorrect information about a right to object, and suggested the CRA review its practices, it held that such advice could not create a substantive right to appeal that statute prohibits.

Ruling and outcome

The Federal Court of Appeal dismissed the appeal, noting Mr. Bergman's able submissions for the appellant. The Crown — His Majesty the King, the respondent — was the successful party, and the Court ordered the appeal dismissed with costs in the Crown's favour. The reasons do not fix a specific dollar figure for those costs, so the precise amount awarded is not specified in the decision.