Check that your Eurail Pass is valid for the time period you are taking the Eurostar. For example, if you have a France Eurail pass for two months, your travel on the Eurostar must occur during this two-month time frame.
Contact the travel agent at which you purchased your Eurail Pass, such as the Rail Europe office, and ask for the Passholder Fare. You'll receive the discounted fare for Eurail Passholders if it is available. Book early, since the Passholder Fare increases the closer it is to your travel date.
For last minute bookings, go to a Eurostar office in London, Paris or Brussels or visit the Eurostar Customer Service desk at your departure train station. Show your Eurail Pass and ask for the Passholder discount.
Your Passholder Fare ticket does not need to match the fare on your Eurail Pass. For example, if your Eurail Pass is for first-class travel, you can buy a coach seat on the Eurostar.
Note that you cannot reserve a Passholder Fare on the Eurostar website.
Arrive at the train station 45-minutes prior to boarding. Go through security, show your Eurostar ticket and pass, then follow the signs to your boarding area.
If this is the first-time you are using your Eurail Pass, stop at the Customer Service desk before going through security to validate your pass. If you are using a Eurail Pass with flexible days, you must have a valid Eurail Pass. Luckily, you do not need to use up one of your flexible days with this trip since you have purchased a Eurorail Passholder ticket.
Find your train when boarding is announced. Follow the crowd to the train track. Walk down the platform and look at the Car Number next to the door of the train. Match the Car Number to the number on your ticket. Enter the train and find your assigned seat as printed on your ticket.
Look out the window as the train is moving. When you see the train accelerating downward and the scenery outside turns black, you are traveling through the Chunnel. The Chunnel crossing takes about 25 minutes.
