Verify your card and receive a 2-day ticket for the price of the 1-day ticket. Fill in the form and redeem your voucher at

ISIC serial number
E-mail address
Your e-mail address is used only for delivery of your voucher and will not be used for any other purpose unless permission is given.
Your name (as stated on your card)
  I agree for ISIC Global Office to use my e-mail address for the purpose of market research.