Export first, install afterwards
The individual certificate is requested and downloaded on a computer. To take it to the phone you need the file exported with its private key. How to do it is in exporting the certificate and making a backup.
Be careful how you move the file. Whoever has file and password can sign in your name. Do not send it by email or messaging, and delete it from the phone as soon as it is installed.
Differences between iPhone and Android
On iPhone the certificate installs as a configuration profile and you then have to trust it manually in settings; until you take that second step, some apps do not see it. On Android it is imported from security and credential settings, and the system requires a screen lock before allowing installation.
In both cases some apps and browsers use their own store, so it may work in one and not another. It is the same thing that happens on a computer with Firefox.
What you can do from the phone
Check files, download certificates, access Importass and the electronic offices, and receive notifications. For signing documents the comfortable route is still the computer with the official application: see signing a PDF with a digital certificate.
What really works from a mobile
With the certificate installed on the phone, checks and downloads work well: the employment history report, Tax Agency certificates, padrón slips, DGT fine checks and the status of immigration files.
Where the phone falls short is filing submissions with attachments and signing with AutoFirma, which many offices only support on desktop. To fill in a long form or upload several scanned documents, the computer is still faster and fails less.
An alternative many people overlook: to identify yourself without a certificate there is Cl@ve, which usually runs more smoothly on a phone. It does not work for everything, but for Social Security and Tax Agency checks it covers most cases.
Security on a device that gets lost
A phone is lost or stolen far more easily than a computer, and it carries your electronic identity. Three minimum measures if you decide to install it there:
- Device lock with a code or biometrics, no exceptions. Without it, the certificate is available to anyone who picks up the phone.
- Delete the .pfx file from the phone as soon as installation is done and checked. Once installed it is no longer needed, and if it stays in Downloads it is a copy of your signature waiting to be copied.
- Know how to revoke. If you lose the phone, the certificate is revoked from the FNMT's electronic office or in person at a registration office. Revoking makes it useless at once, even if someone has the file.
Want the certificate on your phone?
We install it on your computer and your phone and leave it tested in the offices you will use.
Frequently asked questions
Can I request the certificate directly from my phone?
The FNMT provides a route to obtain it with a mobile device. Check the technical requirements in its electronic office before starting.
Do I need the file's password?
Yes, without it the phone cannot import the certificate.
Is it safe to have the certificate on a phone?
It is if the phone has a screen lock and you delete the loose file after installing. If you lose the phone, revoke the certificate.
Does it work in every browser on the phone?
Not always. Some apps use their own certificate store and may not see it.
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
- Spanish Government electronic signature portal: downloads
- Importass, portal of the Social Security Treasury
- Social Security electronic office
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.