Power of attorney

written legal authority to act for another person

A power of attorney (POA) 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 granter (of the power), and the one authorized to act is the agent or attorney-in-fact
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Durable power of attorney Continuing power of attorney Death & health care An 'advance directive' document that allows Pts to appoint a [more]Power of attorney - Community and Resources

Noun
1. a legal instrument authorizing someone to act as the grantor's agent
(hypernym) legal document, legal instrument, official document, instrument
(hyponym) stock power
(classification) law, jurisprudence

A written authorization allowing a person to perform certain acts on behalf of another, such as movement of assets between accounts or trading in a person's securities portfolio.