The Restatement of Agency is the American Law Institute’s organized synthesis of the common law rules that govern relationships in which one person acts on behalf of another. First published in 1933 and now in its third edition, adopted in 2005 and published in 2006, it distills thousands of court decisions into a structured framework that judges across the country treat as highly persuasive authority when resolving disputes among principals, agents, and third parties.1The American Law Institute. Restatement of the Law Third, Agency It is not binding law the way a statute is. Courts cite it to fill gaps, clarify ambiguities, and justify rulings in agency disputes.
How an Agency Relationship Forms
Under § 1.01 of the Restatement (Third), an agency relationship forms when one person (the principal) manifests assent that another person (the agent) will act on the principal’s behalf and subject to the principal’s control, and the agent consents to do so.2Legal Information Institute. U.S. Constitution Annotated – Agency and Standing Both sides must show consent through external expressions: words, written instructions, or conduct. Private, unexpressed intentions don’t count. What matters is what a reasonable observer would conclude from the parties’ behavior.
Control is the distinguishing feature. The principal doesn’t need to micromanage every step but must retain the right to define the objectives and direct the general course of the agent’s conduct. If someone performs work without being subject to that kind of direction, the arrangement looks more like an independent contractor relationship than an agency, and the legal consequences differ sharply, especially around liability for injuries or broken contracts.
Who Can Be a Principal or Agent
Not everyone can form an agency relationship. Under § 3.04, an individual can act as a principal only if they have the legal capacity to perform the act themselves. A minor or someone declared legally incompetent may lack capacity to appoint an agent for certain transactions. The rules are more forgiving on the agent side: under § 3.05, virtually any person can be empowered to affect another’s legal relations. The agent’s own capacity determines what duties and liabilities the agent personally takes on, but it doesn’t prevent the agent from binding the principal.
The Agent’s Authority to Bind the Principal
Most agency disputes come down to a single question: did the agent have power to bind the principal? The Restatement identifies several distinct types of authority, each with its own requirements and consequences.
Actual Authority
Actual authority exists under § 2.01 when the agent reasonably believes, based on the principal’s communications, that the principal wants the agent to act. It splits into two subcategories. Express authority covers tasks the principal specifically directed, such as instructions in a contract or a power of attorney document. Implied authority under § 2.02 extends to steps that are necessary or incidental to carrying out those express instructions, even if the principal never mentioned them. A manager hired to run a retail store has implied authority to order inventory, schedule employees, and handle day-to-day vendor payments, because those tasks are inherently part of running the store.
Apparent Authority
Apparent authority under § 2.03 doesn’t depend on what the agent believes. It depends on what a third party reasonably believes based on the principal’s own manifestations. If a business gives an employee a company uniform, a marked vehicle, and a desk in the front office, a customer who relies on those signals is protected when entering a contract, even if the employee had no actual permission to make the deal. The doctrine shields people who reasonably rely on outward appearances of authorization. The principal bears the risk of the signals it creates.
Estoppel
Section 2.05 reaches situations where no agency relationship exists at all, but the supposed principal is still held liable. This happens when a person intentionally or carelessly causes a third party to believe someone is their agent, and the third party changes position in reliance on that belief. It also applies when someone learns that others believe an agency exists and fails to correct the misunderstanding. Estoppel differs from apparent authority because it doesn’t require a true agency relationship. It is a fallback doctrine that prevents a person from denying a relationship they effectively allowed to appear real.
Subagency
Under § 3.15, an agent can appoint a subagent to perform functions the agent has agreed to handle for the principal, but only if the agent has actual or apparent authority to delegate. When a valid subagency is created, the subagent becomes an agent of both the original principal and the appointing agent. The appointing agent remains responsible to the principal for the subagent’s conduct, and the principal can be held liable for the subagent’s acts. This structure is common in insurance, real estate, and corporate settings where hierarchical delegation is routine.
Ratifying an Unauthorized Act
When an agent acts without authority, the principal can still adopt the transaction after the fact. Under § 4.01, ratification is the affirmation of a prior unauthorized act, giving it legal effect as though the agent had actual authority from the start. A principal ratifies by expressing assent or by engaging in conduct that justifies a reasonable assumption of consent.
The power comes with constraints. Under § 4.02, ratification is retroactive, reaching back to the moment of the original act. But that retroactive effect has exceptions: it cannot favor someone who induced ratification through misrepresentation, cannot be used by an agent against a principal who ratified only to avoid a loss, and cannot diminish the rights of third parties who acquired interests in the subject matter before ratification occurred.
Timing matters. Under § 4.05, ratification becomes unavailable if the third party has already manifested an intent to withdraw, if circumstances have materially changed in a way that would make it unfair to bind the third party, or if a specific deadline has passed. The principal must have knowledge of the material facts involved in the original act (§ 4.06), and the ratification must encompass the entire transaction. Cherry-picking favorable parts of an unauthorized deal while rejecting the rest isn’t permitted (§ 4.07).
Disclosed, Unidentified, and Undisclosed Principals
Agency law recognizes three categories based on what the third party knows about the principal. A disclosed principal is one whose identity the third party knows. An unidentified principal, called “partially disclosed” under the older Second Restatement, is one whose existence the third party suspects but whose identity remains unknown. An undisclosed principal is one whose existence the third party doesn’t know about at all; the third party believes they are dealing with the agent personally.
The distinction drives who can be sued and who is personally liable. When the principal is disclosed and the agent acts with authority, the principal is bound on the contract and the agent generally is not. When the principal is unidentified, the agent becomes a party to the contract alongside the principal and is personally liable unless the parties agree otherwise. When the principal is undisclosed, the principal is liable if the agent had actual authority, but apparent authority cannot apply because the third party didn’t know a principal existed. If the third party later discovers the undisclosed principal, the third party can choose to hold either the agent or the principal to the contract. The principal cannot enforce the contract if doing so would materially change the third party’s obligations or if the agent fraudulently concealed the principal’s involvement.
Fiduciary Duties the Agent Owes
The agency relationship is fiduciary at its core, which means the agent owes the principal obligations that go beyond ordinary commercial fair dealing. Chapter 8 of the Restatement lays out these duties in detail.1The American Law Institute. Restatement of the Law Third, Agency
Loyalty
Loyalty is the foundational obligation. The agent must act solely for the principal’s benefit in all matters connected to the agency. Self-dealing is the classic violation: an agent hired to sell property cannot secretly buy it for themselves without full disclosure. The duty also prohibits competing with the principal, diverting business opportunities, and exploiting the principal’s confidential information for personal gain. An agent who violates these duties can be forced to surrender any profits and may face substantial civil damages.
Care, Competence, and Diligence
Agents must perform their work with the skill and attentiveness that someone in their position would normally exercise. A financial advisor managing investments is held to the standard of a competent financial professional, not merely a reasonable layperson. If negligent performance causes the principal financial losses, the agent is personally liable for those losses. This duty also includes an obligation to keep the principal informed of facts that might affect the principal’s decisions. Withholding bad news is itself a breach.
Accounting
Under § 8.12, agents must keep accurate records of money and property received or spent on the principal’s behalf and make those records available to the principal. Commingling the principal’s funds with the agent’s own money violates this duty, as does handling the principal’s property in a way that makes it appear to belong to the agent. The accounting obligations exist to maintain financial transparency and give the principal the ability to verify that resources are being used properly.
Duties After the Relationship Ends
Some duties survive the end of the agency relationship. Under § 8.05, an agent’s obligation not to use or disclose the principal’s confidential information continues after termination. A former employee who takes a client list or trade secrets to a competitor violates this ongoing duty. Section 8.04 acknowledges that agents may prepare for future competition while still employed. Looking for a new job or planning to start a competing business isn’t itself a breach, as long as the agent doesn’t actually compete or misuse confidential information before the relationship ends.
When the Agent’s Knowledge Becomes the Principal’s
One of the more counterintuitive features of agency law is that an agent’s knowledge can be legally attributed to the principal, even if the principal never actually learns the information. Under § 5.03, when an agent knows or has reason to know a fact that is material to the agent’s duties, that knowledge is imputed to the principal for purposes of determining the principal’s legal obligations to third parties.3The American Law Institute. 11th Circuit Court of Appeals Cites Restatement 3rd of Agency A corporation cannot avoid liability by claiming its CEO never passed critical information to the board, if the CEO knew it and it fell within the CEO’s responsibilities.
The major exception is the adverse interest rule under § 5.04. When an agent acts adversely to the principal, intending to serve only the agent’s own purposes, the agent’s knowledge is not imputed. This protects principals from being charged with knowledge their agent was actively trying to hide. But the exception has its own limits: imputation is restored when a third party dealt with the principal in good faith and needs protection, or when the principal ratified the agent’s conduct or knowingly kept its benefits. A third party who knows the agent is acting against the principal’s interests cannot claim good-faith protection.
Who Pays When Things Go Wrong
The Restatement addresses liability on two tracks: contracts and torts.
Contract Liability
When an agent enters a contract with actual or apparent authority, the principal is bound by its terms. An agent who acts for a disclosed principal generally drops out of the transaction and has no personal liability. An agent who exceeds their authority, or acts without it, may be personally liable to the third party for breach of an implied warranty of authority. The agent effectively represents, “I have the power to commit my principal to this deal,” and if that turns out to be false and the principal doesn’t ratify, the agent is on the hook.
Vicarious Liability and Respondeat Superior
Under § 7.07, an employer is vicariously liable for torts committed by an employee acting within the scope of employment. The employee must be performing assigned work or engaging in conduct subject to the employer’s control. A delivery driver who causes an accident while making rounds exposes the employer to liability for the resulting injuries. The Third Restatement deliberately moved away from the older terminology of “master and servant,” replacing it with “employer and employee” while preserving the same underlying principle: if you control how the work gets done, you bear responsibility for the harms that come from it.
The critical boundary runs between employees and nonemployee agents, the Restatement’s replacement for “independent contractors.” The distinction turns on whether the principal controls or has the right to control the manner and means of the agent’s work. A company that hires a plumber to fix a pipe and doesn’t direct how the plumber does the job is generally not vicariously liable if the plumber injures someone. A company whose delivery driver follows company-prescribed routes, drives a company truck, and wears a company uniform almost certainly has an employee, and vicarious liability follows.
Frolic and Detour
Even when an employer-employee relationship clearly exists, vicarious liability has limits. An employee’s conduct falls outside the scope of employment when it represents an independent course of action not intended to serve any purpose of the employer. Courts frame this as the difference between a “detour” and a “frolic.” A driver who takes a slightly longer route to grab coffee is on a minor detour, and the employer probably remains liable. A driver who abandons the delivery route entirely to visit a friend across town is on a frolic, and the employer is likely off the hook. Courts weigh how far the deviation went in time and distance, whether any part of the employee’s motivation was to serve the employer, and whether similar deviations are common for employees in that role. Once an employee abandons a frolic and returns to work duties, vicarious liability reattaches.
Direct Liability of the Principal
Separate from vicarious liability, § 7.03 establishes that a principal can be directly liable for their own failures regarding the agent. This includes negligence in selecting, supervising, or controlling the agent. Hiring someone with a known history of reckless driving to operate a delivery vehicle, or providing faulty equipment that leads to an injury, creates direct liability that doesn’t depend on whether the agent was an employee or an independent contractor. Direct liability reaches situations where the principal’s own conduct was the problem.
The Agent’s Personal Liability
Agents aren’t always shielded just because they acted for a principal. An agent who commits a tort is personally liable regardless of whether the principal is also liable. An agent who enters a contract without authority faces liability for breach of the implied warranty of authority. And an agent dealing on behalf of an unidentified principal becomes a party to the contract and is personally liable unless the parties agree otherwise.
How Agency Power Ends
Agency relationships don’t last forever, and Chapter 3 of the Restatement identifies several events that bring them to an end.1The American Law Institute. Restatement of the Law Third, Agency The most straightforward triggers include completion of the task the agent was appointed to handle or expiration of the agreed time period. Either party can also end the relationship unilaterally: the principal by revoking authority, or the agent by renouncing it. Unilateral termination ends the agency power immediately, though the party who walks away may still owe damages if the termination breaches a contract. Death or loss of legal capacity of either party also terminates the relationship as a general rule.
Powers That Can’t Be Revoked
The most important exception to the principal’s ability to revoke authority is the power given as security under § 3.12. When an agent holds a power that protects the agent’s own legal or financial interest, that power can be made irrevocable. A lender who holds a power of attorney to sell collateral if a loan goes into default holds a power given as security. Under § 3.13, this type of power survives events that would normally terminate an agency: the principal’s attempted revocation, loss of capacity by either party, and even the death of the principal if the underlying obligation doesn’t terminate at death. The same rules apply to irrevocable proxies for voting rights, which are common in business transactions. These exceptions reflect a practical reality. When the agent’s power exists to protect the agent’s own stake in a deal, letting the principal unilaterally pull the plug would defeat the purpose of granting the power.
Inherent Authority Dropped
One notable change in the Third Restatement was the elimination of “inherent authority” as a standalone concept. The Second Restatement used this term to describe an agent’s power that arose solely from the agency relationship itself, separate from actual authority, apparent authority, or estoppel. The Third Restatement dropped the term entirely, concluding that other doctrines, particularly apparent authority, estoppel, and the agent’s reasonable interpretation of the principal’s instructions, adequately cover the same ground. The one area where the concept effectively survives is under § 2.06, which binds an undisclosed principal to an agent’s unauthorized acts when those acts are usual or necessary in the type of transaction involved.