How to back up your electronic certificate
Skip information indexWindows - Copy the certificate in Microsoft Edge
To make a copy of the electronic certificate from Microsoft Edge, access the "Settings and more" menu located at the end of the address bar identified with the three horizontal dots icon and enter "Settings".
Click on "Privacy, search and services" located on the left side, locate "Security" and click on "Manage certificates".
Your electronic certificate should appear in the "Personal" tab. To make a backup (export), select the corresponding certificate and click "Export...".
The "Export Wizard" then opens. Click "Next" and then check the "Export private key" box (if you have just obtained your certificate and cannot check it, there may have been a problem in the download or installation; In that case, contact the certificate issuing entity).
On the next screen, leave the options that appear marked by default and press "Next". Check the "Password" box and set a password for security. This option is essential to later import the certificate in a browser such as Mozilla Firefox. If you forget the password there will be no way to recover it. Press "Next."
Click "Browse" to choose the location to save the copy of the certificate, set a name, and click "Save," "Next," and then "Finish."
If everything went well, the message "The export was successful" will appear.
The icon for a valid copy made will be an open envelope with a certificate showing and a key and the .pfx extension. If you do not see the extension, right-click on the certificate icon and go to "Properties".
If you cannot check the "Export private key" box, the result would be an invalid copy (the file would have a .cer extension and the icon would be a certificate without any key). The private key is the personal information that the certificate contains and without which it is not possible to sign.
If the copy was not valid, it would be installed in the "Other people" tab instead of in the "Personal" tab and the certificate would not be valid to work on the AEAT page. If at any time you need to reinstall (import) the certificate and you do not have a valid copy, you must request a new certificate.