Spirakos v Deputy Commissioner of Taxation

The case of *Spirakos v Deputy Commissioner of Taxation* concerned an appeal to the High Court of Australia regarding the Commissioner's assessment of additional tax under section 226 of the *Income Tax Assessment Act 1936* (Cth) (the Act). The appellant, Mr. Spirakos, had been assessed for additional tax on the basis that he had failed to take reasonable care in providing information to the Commissioner, which resulted in an understatement of his taxable income. The dispute centred on whether the Commissioner had discharged the onus of proof required to establish that Mr. Spirakos had failed to take reasonable care.

The High Court was required to determine whether the Federal Court of Australia had erred in upholding the Commissioner's assessment of additional tax. Specifically, the Court had to consider whether the evidence before the Commissioner was sufficient to support the conclusion that Mr. Spirakos had not taken reasonable care in preparing and lodging his tax returns, thereby leading to the understatement of his assessable income.

In their joint judgment, Hayne and Crennan JJ found that the Commissioner had not discharged the onus of proof. Their Honours explained that while the Commissioner is entitled to rely on the presumption of regularity, this presumption does not extend to establishing the subjective state of mind of the taxpayer, namely, whether they took reasonable care. The Court held that the Commissioner must adduce evidence to demonstrate that the taxpayer's conduct fell short of the standard of reasonable care. In this instance, the Court concluded that the evidence presented by the Commissioner was insufficient to establish that Mr. Spirakos had failed to take reasonable care, and therefore the assessment of additional tax was not justified.