delivered the opinion of the court.

In an action for damages sustained through the negligent driving of a truck, plaintiff appeals from the judgment dismissing her complaint on the ground that the action is barred by limitations.

Appellant contends that the lower court erred in deciding that the action had prescribed. ■ She argues in the first place that, although the complaint was filed more than one year after the accident, it avers an extrajudicial claim which interrupted the period of prescription. The extrajudicial claim was made against one of the defendant parties alone, that is, against the company which insured the damages caused by the truck belonging to another defendant.

The lower court decided that the' claim filed against the insurance company did not interrupt the period of prescription, inasmuch as the insurer was not the debtor of the plaintiff, nor was the latter the former’s creditor. Appellant urges that she is the creditor of the insurer particularly in *205view of § 175 of the Insurance Law of Puerto Rico1 under which a claim may be filed jointly against the insurer and the assured. But assuming, without deciding, that the appellant is the insurer’s creditor and that her extrajudicial claim interrupted the period of prescription, and hence the action against the insurer is not barred, the action is still barred as against the assured and, consequently, the complaint does not state a cause of action either against the assured or against the insurer, inasmuch as the latter is liable only if the former is.2

Although appellant has not argued the point, we have carefully considered the possibility that the interruption of the prescriptive period with regard to the insurer might be effective as against the assured. But we find that under the Civil Code the only case where an extrajudicial claim made against one debtor prejudices another is in that of several, or solidary, obligations.3 Solidarity is not presumed, and unless expressly contracted4 it does not exist. And although in the prayer of her complaint appellant asks that defendants be adjudged severally to pay the damages, the complaint fails to allege that the insurer expressly bound itself to pay, jointly and severally with the assured, the damages which the assured’s truck might cause a third person. The allegations, of the complaint, therefore, do not permit the conclusion that the extrajudicial claim addressed to the insurer prejudiced the assured, since the existence of a solidary obligation is not alleged, nor is it alleged that the claim was addressed to the insurer as the agent or representative of the assured.

We conclude that, even assuming that the complaint shows that the period of prescription was interrupted in so far as the insurance company is concerned, it does not appear that the interruption prejudiced the assured. This being so, the *206action is barred against the assured. And since the insurer is not liable unless the assured is, the complaint does not state a cause of action against the insurer.

Appellant brings up another argument: that the insurer is estopped from pleading prescription. According to the appellant the estoppel arises from the fact, alleged in the complaint, that when plaintiff wrote to the insurer prior to the prescription of the action, asking the company to state whether it was willing to discuss appellant’s claim, the insurer answered that it was “most willing* to discuss the matter.”

The averment made in the complaint falls far short of constituting an estoppel. The statement of the insurer to the effect that it was willing to discuss the matter is not equivalent to a representation or promise to waive the plea of prescription. Neither does it constitute conduct tending to persuade appellant to postpone her action.5 Besides, an essential element of estoppel is lacking: that the appellant should have changed her position in reliance on the representation or promise of the insurer. Not only is it not alleged that appellant postponed litigation relying on the statement or conduct of the insurer, but it is expressly alleged that the reason for the delay was a different one, that is, “That due to the fact that plaintiff: continued under medical treatment until December 1943, and as the degree of her incapacity resulting from the fracture of the right fibula had not yet been determined, plaintiff did not file this complaint until one year had elapsed after the accident. ”6

There is no basis, therefore, for the estoppel invoked by appellant.

The error assigned has not been committed and the judgment is therefore affirmed.