Article 39.1 LIS (Joint limit)
Regulations: Art. 69.2 Personal Income Tax Law and 39 LIS
The deduction limits provided for in article 39.1 of the LIS are applied in the Personal Income Tax on the quota resulting from reducing the sum of the full quotas , state and regional (boxes  and  of the declaration), in the total amount of deductions for investment in habitual residence (in the case of taxpayers to whom the transitional regime of this deduction is applicable), for investment in new or recently created companies, provided for in article 68.1 of the Personal Income Tax Law , and for actions for the protection and dissemination of Spanish Historical Heritage and World Heritage (∑ boxes  and  ; minus ∑ boxes ;  and , respectively) .
In relation to these limits, article 39.1 of the LIS establishes that the amount of deductions to encourage the performance of certain activities (excluding the deduction for expenses of executing a foreign production of cinematographic feature films or audiovisual works referred to in article 36.2 of the LIS that are not subject to these limits), applied in the tax period, may not exceed jointly of 25 per 100 of the previously defined quota.
However, this limit is raised to 50 per 100 when the amount of the deductions provided for in articles 35 (deductions for research and development activities and technological innovation) and 36 of the LIS (deductions for investments in cinematographic productions, audiovisual series and live shows of performing and musical arts), which correspond to expenses and investments made in the same tax period, exceeds 10 per 100 of the previously defined quota (that is, the total full personal income tax quota, reduced by the deductions for protection and dissemination of Spanish Historical Heritage and World Heritage and for investments in habitual residence and in new or recently created companies).
When there are pending balances of deductions from previous years, the appropriate limit (25 per 100 or 50 per 100) will be applied jointly to the deductions for fiscal year 2021 and the pending balances from previous years .
Note: for the purposes of calculating this joint limit (25 percent or 50 percent) the deduction for foreign film productions in Spain provided for in article 36.2 of the LIS ).