For those who are using our backup card feature in renewals and domain:create. We are going to stop charging back up cards on the 4th of September. We kindly advise you to use our prepaid account instead. You can monitor the prepaid balance here https://www.isnic.is/en/epp#info_account. You can use ERROR_BILLING_FAILURE = 2104 to implement the logic in your client code to retry with a fallback card.
Also there was a recent update in our EPP server, names of contacts can now be updated. See example: https://www.isnic.is/en/api/epp#update_contact.