Authorize.Net CIM: Error when refunding: "Bill To ... Required"

If you attempt to submit a credit memo in the Magento Admin and the transaction fails, review the log located on the server under {Magento site root}/var/log/tokenbase.log and find the related transaction. If this error has a response code of 3, that means the transaction was declined. Ideally, the response should also include additional information on what caused the error but that will not always be the case.

If the response includes any errors with the error code 33, that means that you have a field marked as required in your  Authorize.Net account that Magento is not providing. Authorize.Net details the error as follows:

The field is set as Required in the Merchant Interface but is not being submitted in the transaction request. Ensure that you are submitting the field, or set the field as not required.

To change the field value to not required:

• Login to your Merchant Interface at https://account.authorize.net/ 

• Click Settings in the main left side menu

• Click Payment Form

• Click Form Fields

• Uncheck the field provided in the Error 33 text.

• Click Submit

Following these instructions should resolve the error in question. While Authorize.Net does recommend the Bill To fields be required to "ensure that transactions are run through the AVS Filter", this should instead be enforced in Magento's actual form fields when the order is initially placed. So long as Magento provides the information, the AVS filters should process it.