A power of attorney is a legal document that lets you name someone you trust, often called an agent or attorney-in-fact, to make decisions on your behalf. That authority can cover a narrow slice of your life, like signing paperwork on a specific home sale, or it can span your entire financial and legal picture. You decide the scope, the timeline, and how much oversight your agent has when you set it up. Most people create one alongside a will or as part of a larger estate plan, since it's the tool that keeps things moving if you're ever unavailable or unable to act yourself. Without one in place, loved ones may need to petition a court for guardianship just to pay your bills or make basic decisions, which costs both time and money.