Short answer. No. Article 1895 of the Civil Code carves out a specific exception: when agents have agreed to solidarity, they share responsibility for each other's faults — but not when a fellow agent acted beyond the scope of their authority. The out-of-scope agent alone bears liability for that unauthorized act.
What the law says
If solidarity has been agreed upon, each of the agents is responsible for the non-fulfillment of agency, and for the fault or negligence of his fellows agents, except in the latter case when the fellow agents acted beyond the scope of their authority.
Civil Code, Article 1895 — Effect of Agreed Solidarity. Read the full provision →
What solidarity among agents normally means
When agents agree to be solidarily responsible to the principal, each one becomes answerable for the full consequences of the agency — not just their own share, but for the failings of any of the other agents as well. This is a powerful commitment: if one agent is negligent or fails to perform, the others step up and answer for it. The law in Article 1895 recognizes this arrangement and enforces it. A principal who appoints solidary agents gets added protection because the agents effectively guarantee each other's conduct.
The exception: acts beyond authority are not shared
Solidarity has a firm limit. Article 1895 expressly states that the shared responsibility for fellow agents' faults does not apply when the fellow agent acted beyond the scope of their authority. The agent who exceeded their mandate broke the terms of the agency — they did something the principal never authorized any of them to do. Holding the other agents liable for that unauthorized act would be unjust: they agreed to guarantee proper performance of the agency, not to underwrite every frolic and detour of a co-agent acting on their own initiative.
Identifying what falls inside and outside the mandate
Whether an act is within or beyond the scope of authority depends on the terms of the agency — what the principal authorized the agents to do. A carefully drafted power of attorney or agency agreement defines the scope. If the agent who caused the loss acted on something that was clearly authorized — even if they did it badly — the others share in the liability. If the act was something wholly outside what any of them were authorized to do, only the one who acted bears the consequences. The boundary matters, and it is determined by what the principal's grant of authority actually covered.
What this means for your situation
If your agent clearly exceeded his authority — took an action you never authorized, went outside the scope of the agency in a way that any fair reading of the mandate would confirm — the other two agents are not liable for the resulting loss. The one who acted beyond his authority bears it alone. You can still hold all three responsible for any loss that arose from actions within the scope of the agency. Document precisely what authority you granted, what the agent actually did, and how that action fell outside the mandate. A lawyer can help you analyze the scope question and assess your options against each agent.