Short answer. Yes. Under Article 1904, a commission agent who handles goods of the same kind and mark belonging to different owners must distinguish them by countermarks and designate the merchandise belonging to each principal. So identical goods from several owners cannot be pooled indistinguishably — the agent has to keep clear which goods are yours.
What the law says
The commission agent who handles goods of the same kind and mark, which belong to different owners, shall distinguish them by countermarks, and designate the merchandise respectively belonging to each principal.
Civil Code, Article 1904 — Distinguishing Goods of Different Owners. Read the full provision →
Identical goods must be kept distinguishable
A commission agent often holds goods for several principals at once, and when those goods are alike it becomes easy to lose track of whose is whose. Article 1904 forbids that. The commission agent who handles goods of the same kind and mark, which belong to different owners, shall distinguish them by countermarks, and designate the merchandise respectively belonging to each principal. So where an agent has goods of the same type and mark from different owners, he must mark them apart — countermark them — and record which lot belongs to which principal. The duty exists precisely because the goods are otherwise indistinguishable.
Why the duty matters
Keeping the goods distinguishable protects each principal's ownership and prevents disputes. If identical goods from several owners were simply mixed in a common heap, all sorts of problems follow: which owner bears a loss if part of the stock is damaged or stolen; whose goods were the ones sold; how to return the right quantity and quality to each; whether one principal's goods were used to satisfy another's buyer. Countermarking answers these in advance. Each principal's merchandise stays identifiable, so gains, losses and deliveries can be attributed correctly, and no principal is exposed to the consequences of another's transactions.
It is the agent's responsibility, done at the outset
The obligation falls on the commission agent, and it is meant to be discharged from the moment he takes in the goods, not reconstructed later from memory. He is the one holding the merchandise and the one who can mark and record it as it arrives; the principals, at a distance, rely on him to do so. A commission agent who lumps identical goods together and cannot afterwards say which were whose has failed this duty, and he bears the consequences of the confusion he created — for instance, he may not be able to shift onto a particular principal a loss he cannot prove was that principal's.
If you consign goods to a commission agent
If you hand goods to a commission agent who also handles the same kind of goods for others, you are entitled to have yours kept identifiable — he must countermark and designate your merchandise. So it is fair to ask, when you consign, how he distinguishes different owners' stock, and to keep your own record of what you delivered: quantity, quality, marks and date. If a loss or a dispute later turns on whose goods were whose, the countermarking and the records are what resolve it. An agent who cannot tell your goods from another owner's has not met this duty, and that failure counts against him, not you.