To block your card, you have to go to your customer area in the Mi Correos Prepago app or on the Correos Prepago website. Once inside your profile, click on your active physical or virtual card and within the drop-down menu you can click on block/unlock card.
If any issues arise during the process, you can contact our support team by: emailing to soporte@correosprepago.es or calling the following phone number 919039516.