Just had the same problem after recieving email of failed membership payment

@ZOS_Kevin should have been able to direct you to the existing forum topic for this issue because the changes Zenimax made to their payment processing are extremely well-known amongst their employees:
https://forums.elderscrollsonline.com/en-gb/discussion/658370/unable-to-purchase-crowns

Basically Zenimax's accounts department have turned off card processing for a large number of European banks. There has been speculation in the other topics that this is to save them money, or it is to circumvent their legal obligations under EU/European laws.

Whatever the reason for Zenimax doing this, it means that many of us can no longer use perfectly valid Mastercard or Visa cards to make payments through the ESO store.

Trier_Sero wrote: »

I had the same issue on my second account. I found out that for some reason ESO store now requires that your account region must match the country where you got your credit card from. I was able to resolve the issue by changing my accounts region. Maybe that helps someone here too.

Interesting theory so I checked my account. Both of my cards from 2 different banks were issued in the UK, and my region as per my account page on the ESO website is set to GB. Maybe it will help someone else (hopefully!) but alas, in my case the problem persists despite it already being set up as you've described.