Why can a third party rely on an agent’s apparent authority?

In the law of agency, a third party may rely on an agent’s apparent authority because it is often impossible or impractical for them to verify the precise scope of an agent’s internal authorization.1

Because representation must function efficiently to support commercial and social transactions, the law recognizes that a third party often relies on manifestations of authority provided by the principal, or on the agent’s position (such as a partner or employee) which implies certain standard powers. Expecting a third party to investigate every detail of an agent’s internal mandate would hinder the utility of agency relationships, which are intended to benefit the principal as well.1

Consequently, the doctrine of apparent authority serves as a compromise to apportion the risk between the principal and the third party. By acknowledging that an agent’s external position can serve as an independent ground for representation, the law protects the reasonable expectations of third parties, even when the agent’s actions deviate from the principal’s specific instructions.12