Requirements

Internet Explorer v. 9.0 or later, latest versions of Firefox (v.21 or later), or other compatible browsers (requirements detailed later on this page)
And 1024x768 graphic resolution or superior and small fonts are recommended.
File viewer in PDF format.
Use of electronic certificates and digital signature (see next section).
Limited load of associated documentation (see next section).

Minimum mandatory requirements for the electronic signature by means of certificate

On the link provided, you will be informed on the minimum requirements necessary for using the electronic signature in this application.

https://www.oficinavirtual.pap.hacienda.gob.es/sitios/oficinavirtual/es-ES/SistemasInformacion/SolicitudAccesoSistemas/Paginas/firmaelectronica.aspx

On this link you will find information on:

A recognised electronic certificate, issued by the certification service providers included in the following list ofcertification service providers
To avoid problems with the use of eDNI, the latest version of the cryptographic module of the eDNI, needs to be installed. It is available at http://www.dnielectronico.es/ (download area).
IMPORTANT. In this new version, REDcoa makes use of the @firma client suite (currently in version 1.6.5), replacing SGIFE's extra-light applet, which limited the performance of electronic signatures on Internet Explorer browsers.
Installation manual AutoFirma Manual de instalacion para usuarios.pdf
Downloads area: https://firmaelectronica.gob.es/Home/Descargas.html

Important note: Due to functional requirements, to ensure that only the person who is connected can sign, digital signature is only allowed with an electronic certificate whose associated DNI matches that of the user connected to the application.

Limited loading of associated documentation:

The system stores all attached files of any kind (PDF, ...) in the corporate document manager (SGIFE). A single locator is assigned to each of these files.

There are limitations on the maximum size of each of these files:

The maximum size for files that can be uploaded at the same time is 50MB.
In order to avoid problems, make sure that the maximum size per file does not exceed 15-20MB.

Before depositing the attached files, therefore, check that the size does not exceed the above limit. For example, for PDF type files, it is a good idea to check that the quality of the PDF is sufficient (i.e. no missing pages, pages aren't creased or upside down, no illegible text, ...). For these purposes, the following parameters for the scanning documents are recommended:

Mode: Preferably "grayscale" (or "Black and White", if this is impossible).
Scanned side : Skip blank page.
Points per inch: 200 dpi (Dots Per Inch).

Following these recommendations PDF files of over 200 pages can be generated without difficulty, with images with acceptable resolution. If you have the Professional Adobe application, a very large PDF document can be saved in an optimised form, reducing its size to the same dimensions.

Requirements for client web browsers to be used with this application

The earliest version of Internet Explorer (IE) supported is 9. Later versions can be used with Windows Vista, Windows 7 or Windows 8.

For all versions of IE, to see all the elements in the application and ensure that its Javascript components function correctly, the Compatibility View option should be turned on. Go to the “Tools” menu (or click the cog wheel icon, depending on the version of IE), select Compatibility View settings and add “hacienda.gob.es” to the list of websites that will be displayed in Compatibility View.