Final answer:
A valid agency relationship requires mutual consent, while a written agreement, compensation, and a brokerage license may or may not be necessary depending on the situation.
Step-by-step explanation:
In order for an agency relationship to be valid, mutual consent is a requirement. Mutual consent means that both parties, the principal and the agent, agree to the agency relationship and its terms.
While a written agreement can provide evidence of the agency relationship and may be preferred in certain situations, it is not always required for a valid agency relationship. Compensation may or may not be involved in an agency relationship, depending on the nature of the agreement.
A brokerage license is not a requirement for a valid agency relationship, unless the agency relationship involves real estate brokerage activities.