You will be able to apply the deduction for investment in your main residence when you meet the following requirements:
(i) You have bought a property before 2013 to make it your main residence,
(ii) You have applied the deduction in a tax return prior to 2013.
In order to apply it in your tax return, you must include it in Appendix A.1, in the section corresponding to Deduction for investment in your main residence (applicable when the purchase was made before 1 January 2013 or, in cases of construction, extension, refurbishment or carrying out works and installations to adapt the main residence of people with disabilities when amounts were paid before 1 January 2013). This will include deductions for the acquisition, construction, refurbishment or extension of the main residence. Maximum deductible investment: 9.040 euros.