They steal your money. We sold an item to a customer, yet unfortunately we did not have it in stock anymore. An honest mistake to make. We requested a cancellation but both the buyer and Cardmarket refused this. In response they frozen our account and are keeping our funds (thousands of euro's) locked. We can not withdraw it anymore. This is not legal for them to do, regardless of what is written in their Terms of Service. If human error is not allowed on this site, beware before you list anyting. You risk losing a lot. Cardtrader.com is much better for sellers, trust me.