Your EU driving licence stays valid in Spain — but if it has indefinite validity or more than 15 years to run, you must renew it with the DGT once 2 years of residence have passed; exchanging earlier is voluntary

EU licences don't need exchanging — yours keeps working in Spain. The wrinkle the DGT's own rules add: licences with indefinite validity, or with more than 15 years still to run, must be renewed in Spain once you've been resident for 2 years. Many people choose the voluntary exchange anyway (a Spanish licence simplifies every later renewal); either way, note the date and don't let it surprise you.