IMU taxation for F/1 urban areas: clarifications from the Court of Cassation in judgment no. 26673/2025

The determination of the municipal property tax (IMU) often represents a battleground between taxpayers and municipal administrations, particularly when it comes to classifying borderline areas from a cadastral perspective. An emblematic case is that of the so-called urban areas registered in the F/1 category, which lack a direct cadastral income. The Court of Cassation addressed this issue in its recent and significant judgment no. 26673 of October 3, 2025, which resolved a dispute between L. D. P. and L. S., providing a clear and definitive interpretive framework.

The classification of F/1 areas: neither buildings nor agricultural land

Urban areas classified in the F/1 cadastral category have always posed a problem of tax classification. As they are portions of urban territory that are not built-up in the strict sense, but have undergone modifications due to human intervention, their assimilation into traditional categories for IMU purposes has always been controversial. The Supreme Court, led by President G. M. S. and with Reporting Judge G. L. S., addressed the issue by excluding assimilation to both buildings and agricultural land.

For IMU purposes, the so-called urban areas, whose cadastral classification in category F/1 excludes the attribution of an income, pursuant to art. 3, paragraph 2, letter d, of Ministerial Decree no. 28 of 1998, cannot be equated to 'buildings' - due to the lack of construction in a technical sense, meaning the realization of covered structures on one or more levels - nor to 'agricultural land' - due to the alteration suffered by the natural state of the soil as a result of works attributable to human intervention -, but must be considered as 'buildable areas' within the meaning of art. 5, paragraph 5, of Legislative Decree no. 504 of 1992 (as referred to by art. 13, paragraph 3, of Law Decree no. 201 of 2011, converted with amendments by Law no. 214 of 2011), with the consequence that the tax must be calculated on the basis of the 'market value', taking into account the buildability inferable from the provisions of urban planning.

The calculation of the tax base and market value

As clarified in the principle of law stated above, the Court of Cassation has established a logical and rigorous principle. Since the F/1 area does not feature covered structures, it cannot be considered a building. At the same time, the presence of human works that have altered the natural state of the soil prevents it from being qualified as agricultural land. Consequently, the only viable path is assimilation to buildable areas.

This entails precise rules for the calculation of IMU:

• The tax cannot be calculated on a cadastral basis, given the absence of income for the F/1 category.
• The tax base must be determined starting from the market value of the area.
• Account must be taken of the actual buildability of the land as outlined by the Municipality's urban planning instruments.

Conclusions

Judgment no. 26673/2025 of the Court of Cassation represents a fundamental turning point for the management of local taxes. For taxpayers owning F/1 areas, this decision requires a careful verification of the market values applied by Municipalities, avoiding arbitrary or disproportionate taxation. For municipal tax offices, on the other hand, a clear interpretive path is outlined that reduces the risk of litigation, anchoring the tax claim to objective criteria linked to the actual urban planning of the territory.