A Complete Guide
A pension in Spain does not depend on your nationality. It depends solely on the contributions (cotizaciones) you have paid into the Social Security system (Seguridad Social).
Spanish contributions: At least 1 year must have been worked directly in Spain.
Under such agreements, each country pays a pension only for the work period completed on its own territory. Spain will pay only for your Spanish contribution period.
Two components of your pension:
earned + supplementary payment
Is it worth overpaying contributions?
Professional status in Spain:
Education and professional qualifications: