You don't need to book in advance...just turn up and go! There are a number of ways to buy tickets - to suit you.
At the station
You can buy your tickets at any station ticket office or from self-service
machines, but please allow yourself plenty of time, especially at the busiest
periods.
If travelling from Oxford station towards Islip or Bicester you should
purchase your ticket before travelling from either the ticket office or one of
the self-service machines located on the station concourse.
If travelling from Bicester or Islip, you will need to buy your tickets from the guard on-board the train. If there is no guard and you are unable to purchase a ticket you will need to buy one on arrival at Oxford from the staff at the ticket barrier instead.
You can pay for your ticket with cash, credit card, debit card, or cheque (valid cheque card needed).
Self–service ticket machines are located in the centre of the concourse at Oxford, next to the Information Desk. The machines accept cash and most credit and debit cards You can buy a variety of tickets, including those for immediate travel, seven-day season tickets and discounted tickets for railcard holders.
On the Internet
Alternatively, you can book your tickets from the comfort of your home or office - then either collect your tickets from a self-service ticket machines at a station, or have them sent to you by First Class post.
Tickets ordered online will be ready for collection 2 hours after ordering, and can be picked up from either the new new bright blue ticket machines or existing machines, called FastTicket.
By Telephone
You can also buy your tickets by calling 08457 000 125. Open 0700-2200 on weekdays and 0800-1900 at weekends. Most debit and credit cards are accepted. Tickets purchased by phone can be collected from self-service machines at a station, or you can have them delivered by First Class post within three to four working days. You can have them delivered the next day for an additional charge, providing you order before 1600 hours.