In accordance with the legislation in force, in the event of delays of more than one hour in relation to the journey time laid down in the timetable or in the event of a train cancellation that prevents the journey from being completed, customers are entitled to a document attesting to the occurrence and duration of the delay. 
Proof will only be issued on presentation of a valid ticket for the affected train.
Check the conditions for each service.

On Alfa Pendular, Intercidades, Regional and InterRegional services, the document can be requested from the ticket inspector on the train or at a ticket office or Customer Assistance Office up to 2 hours after disembarking or up to 2 hours after giving up the journey in the case of a train cancellation.

On the Lisbon urban service, proof of delay or cancellation can be requested whenever there are delays of more than five minutes or a train is cancelled, upon presentation of a valid ticket for the journeys to be justified.
Proof can be requested from the ticket office at any station or from the Customer Assistance Offices at Rossio or Cais do Sodré stations, within a maximum of one week after the event.

On the Porto urban service, the document can be requested whenever there are delays or a train is cancelled, on presentation of a valid ticket for the journeys to be justified.
The document can be requested at ticket offices or Customer Assistance Offices, either immediately after the event or afterwards, as long as it is possible to check the situation.