How the DGT's position has evolved
Current position
The deduction for investment in primary residence under the 18th Transitory Provision of the Law on Personal Income Tax (LIRPF) requires it to have been applied in a period prior to January 1, 2013. Following the TEAC, its application is permitted if it was not previously carried out due to not being required to file a tax return or due to a lack of full tax liability. It is not possible to apply it if there was an obligation to file a tax return and the right was not exercised.
The DGT's position on transitory provisions is heterogeneous, as each ruling addresses a different TP. There is no single doctrinal evolution, but rather the application of specific criteria for the 9th TP (reduction coefficients), the 15th TP (continuity of rental contracts), and the 18th TP (investment in housing).
Turning points
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Establishes that the signing of a new rental contract after the termination of the initial one is considered a continuation of the previous one for the 15th TP.
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Specifies that the 18th TP requires having applied the deduction before 2013, allowing exceptions for lack of obligation to file a tax return or lack of full tax liability according to the TEAC.
Analysis based on 48 of 51 rulings with a stated position. Updated 19 September 2026.