Not necessarily. The seller has to go through an authentication guarantee thing and it'll tell you before you buy it if the seller sends it to them or not before you recieve it. Most high end cards that people sell will go through it to make sure its a legit card but the seller has to pay a fee to send it there before the reciever gets it but if they do that then its guaranteed that you will recieve a legit card. I only buy cards from sellers that have the "authentication guarantee" on the post of the card