Sign the FatturaPA
Each FatturaPA file transmitted to Exchange System must be signed by the party issuing the invoice by means of a qualified signature certificate.
The signature is necessary because it guarantees:
- the integrity of the information contained in the invoice;
- the issuer's authenticity;
A qualified signature certificate may be obtained from one of the certifiers in the list of authorised certifiers published on the DigitPA website. The following technical constraints must be remembered:
- the Exchange System accepts the following signature formats:
On the basis of the signature format adopted, the file becomes “.xml.p7m” (for CAdES-BES signature) or “.xml” (for XAdES-BES signature).
- CAdES-BES (CMS Advanced Electronic Signatures) with a structure compliant with the public specifications ETSI TS 101 733 V1.7.4, as provided for in the appropriate legislation starting from 1 September 2010,
- XAdES-BES (XML Advanced Electronic Signatures), with a structure compliant with the public specifications ETSI TS 101 903 version 1.4.1, as provided for in the appropriate legislation starting from 1 September 2010. The only method accepted for this type of signature is the “enveloped” method. In addition the XAdES signature must have the Reference element with URI=“” or with URI=“#iddoc” where iddoc is the identity code of the document to be signed: the URI attribute cannot be omitted from the Reference elements.
- the software used to place the signature must be capable of providing the “signing time” parameter, which shows the date and the time of the signature, and which assumes significance as the time reference.The apposition of the time stamp is not instead necessary
The archive file must not be signed electronically but all the FatturaPA files inside it must be.
See the Examples section to see two signed invoices in XAdES and CAdES formats.