A Spanish translation for
power of attorney

There is not a single Spanish translation for power of attorney, but there are translations that are used more often than others.

But before getting to the Spanish translation, it's important to have a general idea of what the English definition means, so as to ensure that the same meaning gets transferred in the Spanish translation.

A simple definition of power of attorney is this one from Wikipedia:

A power of attorney or letter of attorney in common law systems or mandate in civil law systems is an authorization to act on someone else's behalf in a legal or business matter.

The person authorizing the other to act is the "principal" or "grantor (of the power)", and the one authorized to act is the "agent" or "attorney-in-fact". The attorney-in-fact acts "in the principal's name," signing the principal's name to documents and filing suit with the principal's name as plaintiff, for example.

The most common Spanish translation for power of attorney that I've seen is poder notarial. Remember, however, that legal issues vary from country to country and the audience your translating for might have another way of representing the idea in English.