Originally Posted by hillrider

Due to political restrictions, you have to maintain the same country of origin. So you can only exchange your unused ticket, minus change fee, for a ticket for travel from the same country (although the EU being a single market it's considered one country), and this has to be done while the ticket is still valid (generally 1 year from date of issuance) and, in most cases, only if you've cancelled your reservation prior to original travel (a no-show will automatically make you lose the entire value).