I have a Schengen visa. Can I entrust it to Spain?

you can handle it yourself or entrust others to do it, but some people need to be present in person, while others can entrust it all the time.

If you apply for a Spanish visa for many times within five years, your fingerprints and photos have been kept in the system. When you apply, you don't need to enter your fingerprints and photos again, and you can entrust an agent. No matter what kind of Spanish visa you apply for for for the first time, you need to enter your fingerprints and take photos, so you must be present.