A legal agent is a person you authorize to act on your behalf in legal, financial, or personal matters, and once appointed, that agent’s decisions and signatures bind you as if you had made them yourself. The term is broad: it covers the registered agent every business must designate, the person named in a power of attorney, and the attorney you hire for a specific matter. What ties these roles together is the authority you grant and the duties the agent owes you in return.
The Main Kinds of Legal Agents
Most people encounter one of three varieties.
Registered Agent for a Business
Every corporation, LLC, limited partnership, and similar entity is required by its state of formation to designate a registered agent. The role is narrow: accept official legal and tax documents on the company’s behalf, including lawsuits (service of process). State laws generally require a physical street address in the state and availability during normal business hours. The registered agent can be an individual, the business owner, or a commercial service hired for the role.
Agent Under a Power of Attorney
A power of attorney (POA) is a written document that lets you (the “principal”) name someone (the “agent” or “attorney-in-fact”) to act for you. Your agent doesn’t need to be a lawyer. A POA can be general, covering a wide range of financial and legal decisions, or limited to a single transaction such as selling a house or managing one bank account while you’re abroad.
The split that matters most is durable versus non-durable. A non-durable POA ends the moment you lose mental capacity, which is often the exact moment you need help most. A durable POA stays in force even after you become incapacitated. Most states now treat a POA as durable by default unless the document says otherwise, following the pattern of the Uniform Power of Attorney Act, but rules vary by state, so the document should state durability explicitly if that’s what you want.
There’s also a split between financial and healthcare agents. A financial POA covers banking, investments, tax filings, bill payments, and real estate. A healthcare POA (sometimes called a healthcare proxy or medical power of attorney) authorizes a different kind of decision: choosing doctors, approving treatments, arranging care, and in some cases end-of-life choices. The two agents don’t have to be the same person.
An Attorney You’ve Hired
When you retain a lawyer for a lawsuit, a negotiation, or a closing, the lawyer acts as your agent for that matter. Scope is usually defined by the engagement agreement, and the relationship is governed by state bar rules and professional ethics on top of ordinary agency law.
What Your Agent Is Actually Allowed to Do
Not every agent has the same scope of power. Agency law breaks authority into categories that decide whether you’re bound by what your agent does.
Actual Authority
Actual authority is what you directly give your agent. Express authority is what you spell out: “you may sell my car,” “you may sign checks on this account.” Implied authority covers whatever is reasonably necessary to carry those instructions out. If you authorize someone to manage your rental property, they have implied authority to hire a plumber when a pipe bursts, because management can’t happen without repairs.
Apparent Authority
Apparent authority exists when a third party reasonably believes your agent has authority based on your words or conduct, even if you never actually granted it. The classic example: you introduce someone as your “business manager” at a meeting, and the other side later signs a deal with that person. You may be bound even though you never told the “manager” to negotiate anything, because you created the reasonable impression of authority.
This is where principals get burned more often than they expect. Limiting your agent’s authority privately isn’t enough. If you want outsiders to respect those limits, you have to communicate the limits to the people your agent deals with. Otherwise, a third party who reasonably believes your agent has broader power can hold you to whatever the agent agreed to.
Duties Your Agent Owes You
An agent isn’t doing you a favor. The relationship is a fiduciary one, meaning the agent must put your interests ahead of their own, and that obligation is legally enforceable.
- Loyalty. Your agent must act solely for your benefit and avoid conflicts of interest. An agent who steers a deal to a company they secretly own has broken this duty.
- Care. Your agent must use reasonable skill and diligence — the standard of a sensible person handling someone else’s affairs.
- Obedience. Your agent must follow your lawful instructions. An agent who disagrees can resign but can’t simply ignore you.
- Accounting. Your agent must keep records of all transactions and be ready to show you where the money went.
- Disclosure. Your agent must promptly tell you about anything relevant to the agency, including problems.
When an agent breaks these duties, you generally have three remedies: recover damages the breach caused, force the agent to turn over any profit they made from the breach, or undo a transaction that resulted from disloyalty. Family members serving under a power of attorney mishandle finances more often than people assume, and courts take these breaches seriously.
How to Appoint a Legal Agent
The reliable way to create the relationship is a written document. For a power of attorney, writing is virtually always required, and many states require notarization or witnesses. For a registered agent, the appointment runs through your business formation paperwork filed with the state. For an attorney, the engagement letter is the agreement.
Agency can also arise without a formal document. Implied authority can develop from your conduct, such as consistently letting someone negotiate for you. Ratification happens when someone acts as your agent without permission and you later approve it. If a friend signs a contract in your name without asking, and you find out and say “that works for me,” you’ve ratified the act and are bound by it.
Any appointment requires legal capacity on your end: legal age and sound mind at the time you create the arrangement. That’s why estate planners push people to sign durable powers of attorney while still healthy. Once mental capacity is gone, it’s too late to appoint an agent, and your family may have to go through court-supervised guardianship instead.
Who Is Liable When Something Goes Wrong
This is the part of agency law people understand least.
Under the doctrine of respondeat superior, a principal is legally responsible for wrongful acts an agent commits within the scope of the agency. You’re on the hook not because you did something wrong, but because you controlled the agent and their actions represent you. The doctrine does not apply when the person acting is an independent contractor rather than your agent.
Agents don’t get a free pass either. An agent is always personally liable for their own wrongful conduct, including negligence and fraud, whether or not the principal is also liable. And an agent who acts without authority, or exceeds the authority granted, is treated as having implicitly warranted to the third party that the authority existed. When that warranty turns out to be false, the agent is personally liable to the third party for the resulting losses, and you aren’t bound by the unauthorized deal unless you ratify it or the agent had apparent authority.
How an Agency Relationship Ends
Agency doesn’t last forever, and ending it properly matters as much as creating it.
As a principal, you can revoke your agent’s authority at any time. As an agent, you can resign. Either way, if the termination breaches your agreement, the party walking away may owe damages, but the authority itself still ends.
Agency also terminates automatically in some situations. When the agent finishes the specific task they were appointed for, authority expires. If the agreement sets a time limit, authority ends when the clock runs out. Under the common law rule, agency ends immediately on the death of either the principal or the agent. Bankruptcy and incapacity of the principal also terminate a non-durable agency.
The exception is a durable power of attorney, which by definition survives the principal’s incapacity. That’s the whole point of making a POA durable. A durable POA still terminates on your death.
One thing people consistently overlook: revoking authority between you and your agent doesn’t automatically protect you from deals the agent makes afterward. Until third parties learn the authority is gone, they may still reasonably rely on apparent authority, and you could be bound. When you revoke a power of attorney, send written notice to every bank, medical provider, business, and other institution that had a copy of the original. Retrieve and destroy old copies where you can, and keep one marked “REVOKED” in your own records.