In its judgment of 9 December 2025, the Supreme Court has ruled on the correct determination of the taxable income for Property Transfer Tax in cases where a property is acquired by several taxpayers under a joint ownership arrangement

The judgment stems from a challenge to an administrative action in which, after a prior verification of valuation figures, the tax authorities assigned different values to each of the co-owners of the property for the purpose of determining the taxable income. The question raised was whether – even though the valuation check had become final for only one of the co-owners due to the absence of a challenge – it was legally admissible for the Authorities, when resolving a subsequent limited verification procedure regarding the applicable tax rate, to maintain different taxable income bases or whether, on the contrary, a single valuation criterion in accordance with the real value of the property should prevail.

The Supreme Court establishes interpretative criteria regarding assessments in cases of concurrent taxpayers, stipulating that different values cannot be set for the same property for the purposes of determining the taxable income for transfer tax, considering that the tax authorities must avoid and correct these situations of inequality, even ex officio.

The judgement bases this conclusion on the requirement to preserve the principles of economic capacity and tax fairness in the application of the tax.