In point 9 of the General Conditions for contracting and using the universal electronic ticketing system for transport, a responsibility is established for the custody of the public transport card, which carries with it the obligation to communicate its loss or theft to the Consorcio Regional de Transportes de Madrid.

Failure to comply with this obligation, particularly when the card has been used incorrectly, will require the pertinent explanations of the causes that led to the lack of communication of the loss. 

If these explanations are not convincing, the person in whose favor the card is issued must pay the Consorcio Regional de Transportes the amount of 100 euros as compensation to recover it.