Pacific Surfliner tickets are not reserved (except during Thanksgiving), so any tickets you purchase are valid one year from the date the tickets are picked up (printed) from a Quik-Trak machine or station agent. A good strategy is to book reservations in advance and pick up only those tickets you need on the day of departure. If you know you won't be taking the train on a particular day, you can cancel your reservation online, at a Quik-Trak machine, over the phone, or in person at the station. If you paid with a credit card, you will receive a refund back to your credit card as long as the tickets have not been physically picked up (printed).