Spain's education system is high quality, but the language of instruction at state schools is Spanish, which is a significant consideration for non-Spanish-speaking children.
Spanish compulsory education runs from age 6 to 16:
Enrolment requires: child's birth certificate (with apostille if from a non-EU country), padrón certificate (determines school catchment), NIE numbers for child and parents, vaccination record.
Enrolment periods open in April–May for the following September. Missing this window means waiting another year.