How to open a .p7m e-invoice file

What an .xml.p7m file is, why it doesn’t open with a double click and how to read the signed invoice without installing signature software.

What a .p7m file is

An Italian e-invoice is an XML file in the FatturaPA format. When the issuer signs it digitally, the XML file is wrapped in a signature “envelope” (CAdES format) and gets the extension .xml.p7m. The content is the same invoice: the envelope only adds the signature and the signer's certificate.

Why it doesn't open with a double click

Your operating system doesn't know which program to use for a .p7m file, and even if you open it with a text editor you only see unreadable characters: the invoice is inside the envelope, in binary format. Even once extracted, the XML is meant for software, not for people.

How to read the invoice in three steps

1. Open e-invoices.it and drag the .xml.p7m file into the upload area, or select it with the button.
2. Choose View and print: the envelope is removed and the invoice opens in a new tab, with supplier and customer details, line items, VAT summary and payment details.
3. To keep it as a PDF, use your browser's Print function and choose “Save as PDF”.

It also works with several files at once and with ZIP archives containing .p7m files, such as the bulk download from Fatture e Corrispettivi, the Italian Revenue Agency's e-invoicing portal.

What about verifying the signature?

e-invoices.it is for reading the invoice: the signature is removed, but its validity is not verified. If you need a legally valid verification, for example of the signer's certificate, use a digital signature verification program, such as those supplied with signing devices.