After moving to Spain your first tax declarations are due the year after you become tax resident in Spain. The tax year in Spain runs with the calendar year, 1st January to 31st December and the basic rule is that you become tax resident when you’ve spent 183 days in the year in Spain.
Your tax obligations arise for the fiscal year in which you become resident in Spain, not from the date you got your residency.
Here we provide a useful summary and information of the first tax declarations for anyone who doing their Tax in Spain for the first time.