You can use your Youth Card in any class any day of the week on Intercidades, Regional and InterRegional services.
All you have to do is show your Youth Card - physical card or through the Youth Card App installed on your smartphone - at the ticket offices and on board.
CP Services: Intercidades | Regional and InterRegional
The Youth Card is valid between 12 and 30 years old, inclusive, and gives you a 25% discount that cannot be used together with other discounts or special offers in force. Intercidades prices rounded up to the higher 50 cents.
These tickets can be exchanged or refunded.