Worst platform I've delt with, ever...
Not only they made a mess with the payment: first attempt catawiki confirmed the payment, then informed me the it hadn't gone through (because of my bank safety filters), then on the second attempt, I followed the instructions for an IBAN payment; this worked fine, I followed the link provided. Again, catawiki cancelled the payment, because the description of the payment was not clear! Meantime, I had been receiving e mails from a no-reply catawiki e mail, so I had no chance to reply and quickly solve the issue... my purchase was cancelled and when I thought that long waist of time was over, I received another email asking to pay the good (!) And in any case to pay the commission to the seller... I don't even know the amount of the commission! As I consumer I have the right to cancel the order within 14 days without penalties. I don't think they can actually ask me this payment, since two weeks have not yet passed!
If you don't want to take the risk of waisting your time and money, avoid catawiki platform. Be careful!