An extra payment fee means an increase in the final price at the last step of the order, when the payment method is selected and the payment gateway opens. It may be a fee of a few crowns.
We prohibit this practice in our terms and conditions. It is also prohibited by the card schemes (Visa, Mastercard), whose rules we are required to follow.
In most cases, when you pay through a GoPay payment gateway, you should not come across an extra payment fee. If you do, it is not correct and it goes against our terms and conditions.