Ronnyone

There is a number you have that specially recognises your tax information. It was on the old green card at the bottom. I use it if I havent been sent my certicado de retenciónes. It links to how much I have earned for the year.

bobd22

Digital certificate you can transfer as you say so long as you have the original file and password, the original file may be on a stick or in my case an attachment to an email. Really easy to transfer. My original was set up on a computer running Ubuntu and I now have transferred the certificate onto my android phone and tablet.

Albir_Tom

The gestor who made me autónomo made me an appointment for the very next morning at the local EAM prop (Extensión Administrativa Municipal) they did my digital signature within minutes.