I am not sure if this term: Accredit of personality is actually well written and clear in English. It is about the legal representation that someone gives to others in order to act legaly in their name.
Thank you Miss Julie, I do use the term "power of attorney" but only to make reference to the document. Once I have the power of attorney document duly signed, I have to accredit my personality as legal representative of that person
"Power of attorney" means "the authority to act for another person in specified legal or financial matters" (according to the WordReference dictionary). The document of the same name assigns that power/authority to a person.
Are you talking about providing proof to some authority that you hold the power of attorney? "Provide my credentials" or "show evidence of" would be other ways to say it. I've never heard "personality" used in this way.
When you hold power of attorney, you are called the "attorney-in-fact" (although I don't think that term is ever used outside of a courtroom), as opposed to an "attorney-at-law," or lawyer, such as, well, me. (I was both for a while when my mother was ill.)