Why the copy matters so much
The certificate does not live in some FNMT cloud waiting for you to download it again. It is a file on your computer. If you format it, the disk dies or you simply change computer without exporting, that certificate is lost and you must request a new one, identity check included.
With the private key, always. If you export without the private key you get a file containing only the public part: it neither identifies you nor signs. It is the most common mistake.
Treat the file like a key
Whoever has your file and password can identify themselves before the administration as you and sign in your name, with the legal effects that Law 6/2020 gives electronic signatures. Do not send it by email or WhatsApp, do not leave it in a shared folder, and do not use a password you reuse elsewhere.
If you suspect the file has been exposed, revoke the certificate in the FNMT's electronic office and request a new one.
Restoring it on another device
With the file and the password, installing on another computer is straightforward: see how to install the digital certificate. For the phone, see installing the certificate on your mobile.
Where to keep the copy and where not
The exported file is, in practice, your signature. Whoever holds it together with the password can identify themselves as you, file submissions and sign documents with legal effect. That means treating it like a key, not like one more attachment.
- Yes: a USB stick or external disk kept physically, and a password manager that accepts encrypted attachments.
- Yes: a second copy in a different place from the first, because the disk that fails is usually the only one you had.
- No: email, not even to yourself. The inbox is the first place anyone who gets into your account looks.
- No: instant messaging or shared work folders.
- No: the computer desktop with the password in a text file beside it.
And a password different from those you use daily. If the export password matches your email one, a leak compromises both.
When to make the copy and when to redo it
The right moment is the very day of the download, before using it for anything. That is when the certificate is intact, the password is fresh and you still remember where you put it.
After that, three moments require redoing the copy: when you renew the certificate, because the previous file stops working; when you change computer, to verify the copy still imports properly; and when you change the export password.
If you reached this page because you already lost the certificate and had no copy, the short answer is that there is no recovery: the process is repeated in full, in-person identity check included. If you would rather not go through that again, in our service we always hand over the exported copy together with the certificate.
Lost the certificate along with the computer?
With no copy, it must be requested again. We handle it for you and, meanwhile, file your applications with our professional certificate.
Frequently asked questions
What extension does the exported file have?
Usually .pfx or .p12. Both contain the certificate and private key protected by a password.
Can I export it if it has already expired?
You can, but it will be useless: an expired certificate neither identifies nor signs. Renew it or request a new one.
How many copies can I have?
As many as you need. Each copy is a risk, so keep only what is necessary and store them well.
What if someone has my file?
Revoke the certificate in the FNMT's electronic office as soon as possible and request a new one.
Legal basis
- Law 6/2020 regulating certain aspects of electronic trust services
- Law 39/2015 on Common Administrative Procedure, art. 14 on electronic dealings with the administration
- Royal Decree 203/2021, Regulation on public sector action by electronic means
Official sources
- FNMT: individual certificate
- FNMT: renewing the certificate
- Spanish Government electronic signature portal: downloads
- Importass, portal of the Social Security Treasury
Written by Irina Klein. Reviewed by Elena Alonso Volostnova, registered gestora administrativa (ICGA Valencia). Updated on 5 October 2026. This page is general information and does not replace personalised advice on your case.