AEAT response code P1 undefined
When you access a payment or view taxes or online auction deposits, if you are shown the error "Tax Agency Response:[P1 code] undefined" these aspects of the certificate used must be reviewed.
You may be signing with an invalid electronic signature certificate using card certificates (such as the electronic ID).The electronic ID has two certificates:the "Authentication" certificate and the "Signature" certificate.In the last step, you should select the "Signature" certificate.
This error may also occur when attempting to use a revoked or invalid certificate.It is also necessary to check whether there are several electronic certificates installed in the browser, that the corresponding option has been accessed with the correct certificate and that the appropriate certificate is chosen each time the browser requests it.
Bear in mind that if the browser you are using is Internet Explorer, you must close the browser and open it again so that the window that allows you to choose the certificate you wish to use (if there are several certificates installed on the same computer) appears, as Internet Explorer selects the last one used by default.
If an electronic certificate is revoked, it means a valid certificate is cancelled before its expiry date, generally because the holder may suspect that a copy has been made and that their PIN has been divulged.
You can check whether an electronic certificate issued by the FNMT is valid for working on the Tax Agency website by accessing the CERES website (Spanish Certification site).When verifying the status of the certificate, the message "Your certificate has just been verified.You are in possession of a digital certificate FNMT Valid and not revoked. The certificate is working properly.If the certificate is not from FNMT contact the issuing entity.