Under agency law, a person is considered an agent when a principal has authorized them to act on the principal’s behalf, subject to the principal’s control, and they have agreed to do so. That definition sweeps in a lot of people: employees acting within their jobs, corporate officers, business partners, real estate and insurance representatives, securities brokers, lawyers representing clients, and anyone holding a power of attorney. The common thread is authority delegated by one party and accepted by another, which is what allows the agent’s acts to bind the principal legally.
The Three Elements That Make Someone an Agent
The Restatement (Third) of Agency, which courts across the country treat as the leading authority, defines agency as “the fiduciary relationship that arises when one person (a ‘principal’) manifests assent to another person (an ‘agent’) that the agent shall act on the principal’s behalf and subject to the principal’s control, and the agent manifests assent or otherwise consents so to act.”
Three elements have to be present at the same time. The principal consents to the agent acting on their behalf. The agent agrees to take on the role. And the principal retains some degree of control over how the task gets carried out. No formal contract or signed document is required. Consent can be verbal, written, or implied by conduct.
That control element is what separates an agent from a service provider. Hire a plumber and leave them alone to fix the pipe, and they are a contractor, not your agent. Authorize someone to negotiate a deal and tell them the terms you will accept, and that person is your agent.
Employees
Every employee is an agent for tasks performed within the scope of their job. This is one of the most consequential applications of agency law, because employers are legally responsible for what employees do at work. Under the doctrine of respondeat superior, if a delivery driver causes an accident while on a route, the employer typically bears liability for the damages.
The scope question matters. An employee acting within the scope of employment makes the employer liable; an employee off on a personal errand usually does not. Courts have gradually pushed that line outward over the decades to place liability on the party best positioned to prevent harm and insure against it.
Independent Contractors: The Boundary
Not every worker a business hires is an agent. An independent contractor becomes an agent only when the hiring party controls the specific means and methods used to complete the work, not just the end result. Telling a marketing consultant “get us more website traffic” does not create agency. Telling that consultant exactly what to say, whom to contact, and what offers to extend crosses into the kind of control that does.
The IRS applies three categories to the employee-versus-contractor question: behavioral control, financial control, and the nature of the relationship between the parties.1Internal Revenue Service. Topic No. 762, Independent Contractor vs. Employee The classification affects taxes, benefits, and, under agency law, whether the hiring party is on the hook for what the worker does.
Corporate Officers and Business Partners
Corporations can only act through people, which means every corporate officer functions as an agent of the corporation. The CEO, CFO, and other officers derive their authority from the corporate bylaws and board resolutions. When an officer signs a contract within the scope of their position, the corporation is bound. Third parties dealing with a corporate officer are generally entitled to assume that someone holding a recognized title has the authority normally associated with that role, even when internal rules say otherwise.
Partnerships go further. Under the Uniform Partnership Act, adopted in some form across most states, each partner is an agent of the partnership for the purpose of its business. A single partner can bind the entire firm to a contract or a debt if the act falls within the ordinary course of partnership business. The exception is when the partner lacked actual authority and the third party knew it. This is why choosing partners is a high-stakes decision: each one can create obligations the others are responsible for.
Professional Agents
Some professions exist specifically to act as agents for others. These roles carry heightened duties and usually require licensing, because the agent’s actions directly change the principal’s legal position.
Real Estate Agents
Real estate agents represent buyers or sellers in property transactions and owe fiduciary duties of loyalty, disclosure, and confidentiality to the client they represent. Dual agency, where one agent represents both sides of the same transaction, creates an obvious conflict: the seller wants the highest price and the buyer wants the lowest. Most states that permit dual agency require written disclosure and informed consent from both parties, and the agent gives up the right to advocate exclusively for either side. Some states prohibit the arrangement outright.
Insurance Agents
Insurance agents act on behalf of carriers to sell policies and bind coverage. When an insurance agent issues a binding receipt, the applicant has coverage effective from that moment, even before the insurance company formally approves the application. The agent’s authority to bind the carrier makes this possible, which is why insurers invest heavily in training and monitoring: one unauthorized commitment can create coverage the company never intended.
Securities Brokers
Federal law defines a broker as any person engaged in the business of effecting transactions in securities for the account of others.2Legal Information Institute (LII) / Cornell Law School. Definition: Broker From 15 USC 78c(a)(4) A broker executing trades on your behalf is your agent and owes you fiduciary duties. This is distinct from a dealer, who trades on their own account. The agent-principal relationship between broker and investor is what gives rise to suitability obligations and the duty to avoid conflicts of interest.
Attorneys-in-Fact and Lawyers
A power of attorney is a legal document that creates an agency relationship for managing personal affairs. The person granting authority is the principal; the person receiving it is called an attorney-in-fact. Despite the name, the attorney-in-fact does not need to be a lawyer. They are an agent authorized to act within whatever scope the document defines, which can range from signing a single closing document to managing every financial account the principal owns.3Cornell Law School LII / Legal Information Institute. Attorney-in-Fact
A standard power of attorney ends automatically if the principal becomes incapacitated, which is exactly when most people need one. A durable power of attorney solves this by stating that the agent’s authority survives the principal’s incapacity. Under the Uniform Power of Attorney Act, adopted in some form by most states, a power of attorney is presumed to be durable unless the document says otherwise.
An attorney-in-fact who accepts the role takes on fiduciary duties with specific statutory requirements: act in good faith, stay within the scope of authority granted, keep records of all financial transactions made on the principal’s behalf, and avoid conflicts of interest. The record-keeping requirement matters because family members, courts, or successor agents may demand a full accounting later.
Lawyers also serve as agents when representing clients in court, during settlement negotiations, or in transactional work. The scope is usually defined by a retainer agreement, and the lawyer must follow the client’s instructions on major decisions like whether to accept a settlement offer. Agreements a lawyer enters on the client’s behalf bind the client.
The Types of Authority an Agent Can Hold
Whether an agent’s acts bind the principal often turns on what kind of authority the agent had. This is where most agency disputes actually play out.
Express authority is the simplest form: the principal directly tells the agent what they are authorized to do. “You can sign the lease on my behalf” is express authority to sign that lease.
Implied authority extends beyond the literal grant to cover whatever steps are reasonably necessary to carry out the assigned task. An agent told to manage a rental property has implied authority to hire a repair service when the furnace breaks, even if the principal never mentioned furnace repairs.
Apparent authority does not come from what the principal tells the agent. It comes from what the principal’s conduct leads a third party to reasonably believe. A business that puts someone behind the counter with a name tag and a cash register has given that person apparent authority to complete sales, even if internal policy limited them to transactions under fifty dollars. The principal is bound because they created the appearance of authority. Internal restrictions that are never communicated to the outside world do not protect the principal from deals the agent makes.
What Agents Owe Principals
The moment someone becomes an agent, they owe fiduciary duties. These duties fall into three categories: loyalty, obedience, and care. Loyalty means putting the principal’s interests ahead of the agent’s own and avoiding conflicts of interest. Obedience means following the principal’s reasonable instructions. Care means acting with the competence and diligence expected of someone in that role.
These duties are not optional terms that get negotiated into a contract. They arise automatically from the agency relationship. An agent who secretly profits from a deal they are handling for the principal has breached loyalty even if no one ever discussed it. An agent who ignores instructions and improvises has breached obedience. An agent who handles the principal’s affairs carelessly has breached care. Any of the three can produce personal liability for the agent.
When the Principal Gets Stuck With the Agent’s Acts
Being an agent matters mainly because the principal is liable for what the agent does within the scope of authority. That is straightforward when the agent follows instructions. Three scenarios complicate it.
When an agent exceeds their actual authority, the principal is generally not bound, unless the agent had apparent authority. If a third party reasonably believed the agent was authorized, the principal is stuck with the deal and must pursue the agent separately for breach of duty. An agent who falsely claims authority they do not have can be personally liable to the third party for breach of warranty of authority.
When an agent enters a deal without revealing that they are acting for someone else, the agent is personally liable as a party to the contract. The third party dealt with the agent as an individual, and the law protects that expectation. Once the principal’s existence is revealed, both the principal and the agent can be liable, though the third party typically must choose which one to hold accountable. Disclosing the principal’s identity at the time of contracting avoids this exposure entirely.
Employers face vicarious liability for torts their employees commit within the scope of employment. The modern test asks whether the employee was where they were supposed to be, doing roughly what they were supposed to be doing, and whether the harmful act arose from pursuing the employer’s business. A security guard using excessive force to remove a trespasser is probably within scope. An employee assaulting a customer over a personal grudge probably is not. The line is fact-specific and heavily litigated.