Call Eurostar at 011 (+44) 1233 617 575 or go to their Web site (see Resources below).
Book tickets as early as you can for the best rates. Fares for standard class non-exchangeable, non-refundable tickets across the channel start at $90 and go up as seats sell.
Purchase tickets online from Eurostar's Web site. Be aware that the credit card holder and the credit card must be presented at the station to pick up the ticket. You cannot buy a ticket for someone else online unless you plan to pick it up.
Choose seats when you book your ticket. All seats are reserved. When purchasing online, you can choose between window and aisle only. When purchasing on the phone, you can request specific seat assignments. If you don't like your seat, change it before checking in at a station kiosk.
Check in at least 30 minutes prior to your trip if you are traveling in standard or leisure select class. Tickets are taken by an automated ticket machine or at a kiosk. You must pass through security prior to entering the terminal.
Pack appropriately. You can carry your own bags on the train and there is no weight limit for baggage. If you wish to check your bags, there is an extra fee.