AutoFirma — why signing fails, and what each error means
AutoFirma is the program Spain uses to sign things with your digital certificate. It only exists for Windows, Mac and Linux — there is no iPad, iPhone or Android version, so an owner working only from a phone cannot register at all. Most other failures come down to three things: an expired certificate, a certificate your browser cannot see, or a fault at the government's end.
First, the thing nobody tells you
AutoFirma runs on Windows, Mac and Linux. There is no iPad version, no iPhone version and no Android version.
This is not a bug or a gap waiting to be filled. It is simply how it is.
If you run your rental from a phone or a tablet — as a great many owners abroad do — you cannot complete the steps that need a signature, and no amount of troubleshooting will change that.
Your options are to borrow or buy a laptop, to use Cl@ve where it is accepted, to appoint somebody with a certificate to act for you, or to use a service that files on your behalf. There is no fifth option, and it is better to know that now than after an evening of trying.
How the pieces fit together
Three separate things have to line up, and the error messages almost never tell you which one has failed.
- Your certificate, installed on your computer.
- Your browser, which has to be able to see it.
- AutoFirma, which the browser hands over to when something needs signing.
On that middle point: Chrome and Edge do not store certificates themselves. They read from your computer's own store. Safari does the same thing through the Mac's Keychain.
So when you visit a Spanish government site, your browser should pop up a small window asking which certificate to use. If that window never appears, AutoFirma is not the problem — your browser cannot see the certificate, and that is where to look.
What each failure means
A red cross and the word ERROR when you sign
Usually AutoFirma and your browser disagreeing, or an AutoFirma installed before your last big system update. Update AutoFirma, close the browser completely — not just the tab — and try again.
The signing window opens, then shuts itself. Over and over.
Usually a certificate your computer can no longer read properly. Removing it and reinstalling from your backup file fixes this more often than reinstalling AutoFirma does.
You sign, the page goes round in circles, and your form comes back blank
The most demoralising one, because it destroys your work as well as failing. It is frequently a problem at the government's end rather than anything you have done.
An error message that says nothing useful
Check your certificate's expiry date before anything else.
An expired certificate does not politely tell you it has expired. The site can simply return a server error, which sends people off investigating entirely the wrong thing.
"Usuario sin autorización", when you are certain the password is right
If you are using the details emailed to you after registering a property, that is why. Those are for connecting software automatically, not for logging in to the website. See submitting guest data.
It works on one computer but not another
A certificate lives on the machine you installed it on. It does not follow you around, and it is not attached to your browser account. To use it elsewhere you have to export it properly and install it there.
If you use a Mac
Mac owners report more trouble, and it has become received wisdom in owner groups that "Apple products are the problem".
The more accurate picture: AutoFirma is supported on the Mac, but it is sensitive to big system updates. After a major macOS upgrade it is usually AutoFirma that needs reinstalling, not your certificate.
Where to get help, realistically
There is no telephone helpline for SES.Hospedajes. Support is by email, in Spanish, and owners have reported waiting weeks for a reply during busy periods.
That is not a reason to panic if a deadline is close. But it is a very good reason not to leave your first registration until the week your first guests arrive.