Short answer. Yes. Article 1905 of the Civil Code lets you demand cash from a commission agent who sold your goods on credit without your consent, but it also expressly leaves the agent entitled to any interest or benefit that the unauthorized credit sale itself produced — you get the certainty of cash, not the extra profit the credit terms generated.
What the law says
The commission agent cannot, without the express or implied consent of the principal, sell on credit. Should he do so, the principal may demand from him payment in cash, but the commission agent shall be entitled to any interest or benefit, which may result from such sale
Civil Code, Article 1905 — Sale on Credit Without Consent. Read the full provision →
The two-part rule
A commission agent needs the principal's express or implied consent before selling on credit. Where he sells on credit without that consent, the Civil Code gives the principal a specific remedy: he may demand from him payment in cash, treating the sale as though it had been a cash transaction from the start. That protects the principal from being forced to wait on a buyer of the agent's choosing, or to carry the credit risk of a sale he never approved.
Why the agent keeps the extra
The same sentence that gives the principal the cash option also says the agent shall be entitled to any interest or benefit, which may result from such sale. The law does not let the principal take both the certainty of immediate cash and whatever additional interest or profit the credit arrangement produced. Having the option to demand cash now rather than wait out the credit terms, the principal who exercises it receives exactly that: the cash value of the sale. Any upside the credit sale generates belongs to the agent who took the unauthorized risk.
The demand is the principal's choice, not automatic
Article 1905 gives the principal the option to demand cash; it does not say the credit sale is void or that the principal must reject it. A principal who prefers the credit sale as made, because the buyer is reliable or the terms are favorable, is not forced to invoke the cash demand and unwind it. Whether to demand cash or accept the sale as the agent actually made it is the principal's call, and each choice carries different consequences for who ends up with the extra return the credit terms produced.
What this provision does not cover
Article 1905 addresses the commission agent's want of authority to sell on credit and what happens to the resulting profit; it does not itself set out separate consequences for other unauthorized acts an agent might commit, and it does not excuse an agent from liability the principal may otherwise have for losses caused by the unauthorized sale, such as a buyer who defaults. Those questions turn on the general rules governing an agent who exceeds the authority given, applied to the specific facts of the transaction.