Does the out-of-court claim against the insured interrupts the prescription against the insurer?

Yes, indeed, according to the Spanish Supreme Court, the out-of-court claim against the insured also interrupts the prescription against the insurer.

The Judgment of the Supreme Court No. 294/2022, of April 6, issued by the Civil Chamber, appeal No. 1134/2019, maintains that the out-of-court claim against the insured also interrupts the prescription with respect to the insurer, in accordance with the provision contained in art. 1974.I of the Spanish Civil Code (from now on CC).

If the liability of the insurer, which is required by direct action of the injured party provided for in art. 76 LCS ("Ley de Contrato de Seguro": Spanish Insurance Contract Law), has as an implication the responsibility of the insured, the extrajudicial claim against the insured also interrupts the prescription with respect to the insurer, in accordance with the provision contained in art. 1974.I CC.