In a principal-agent relationship, the principal gives the agent authority to act on behalf of the principal, and to bind or obligate the principal to contracts and other legal obligations, as permitted by the scope of the agency (authority). An agent’s authority may be sufficient to bind or obligate the principal if the authority was expressly given to the agent (actual authority), or if it was implied to other persons that the agent had authority to act on behalf of the principal (apparent authority)—such as by the principal’s adoption of the agent’s prior actions on behalf of the principal.

In Maryland, as in other states, the principal-agent relationship is governed by common law principles of agency, which dictate that a principal can authorize an agent to act on their behalf and enter into binding agreements. The agent's authority can be 'actual authority,' which is explicitly granted by the principal to the agent, either in writing or verbally. Alternatively, an agent may have 'apparent authority,' which arises when a principal's actions or communications suggest to third parties that the agent is authorized to act, even if the principal has not explicitly granted such authority. If a third party reasonably believes an agent has the authority to act based on the principal's conduct, the principal may be bound by the agent's actions. Maryland courts will look at the interactions between the principal, agent, and third parties to determine whether apparent authority exists. It is important for principals to clearly define and communicate the scope of an agent's authority to avoid unintended obligations.