1627. The principal is bound in favour of third persons for all the acts of his or her agent, done in execution and within the powers of the agency, except in the case provided for in article 1638 of this Book, and the cases wherein by agreement or the usage of trade the latter alone is bound.
The principal is also answerable for acts which exceed such power, if he or she has ratified them either expressly or tacitly.
1628. The principal or his or her legal representative is bound toward third persons for all acts of the agent, done in execution and within the powers of the agency after it has been extinguished, if its extinction be not known to such third persons.
1629. The principal or his or her legal representative is bound for acts of the agent done in execution and within the powers of the agency after its extinction, when such acts are a necessary consequence of an affair already begun.
He or she or his or her representative is also bound for acts of the agent done after the extinction of the agency by death or cessation of authority in the principal, for the completion of an affair, where loss or injury might have been caused by delay.
1630. The principal is liable to third parties who in good faith contract with a person not his or her agent, under the belief that he or she is so, when the principal has given reasonable cause for such belief.
1631. He or she is liable for damages caused by the fault of the agent, according to the rules declared in article 986.