Every time you receive an electronic invoice you find a file with the .p7m extension and you wonder what it is and how to open it. In this guide we clearly explain what the .p7m electronic invoice file is and how to read its contents.
What is .p7m file
The .p7m is a digitally signed file according to the PKCS#7 / CAdES standard. In practice it is a sealed "envelope" that contains two things:
- the actual electronic invoice, in XML format;
- the digital signature and the certificate of the person who issued the invoice.
The `.p7m` extension actually means "PKCS#7 message": not a new type of document, but a signed wrapper around the invoice.
Because the electronic invoice is signed
The digital signature is mandatory because the invoice passes through the Interchange System (SdI) of the Revenue Agency. The signature guarantees that:
- the invoice really comes from the indicated party (authenticity);
- has not been modified after issue (integrity);
- has legal and fiscal value.
Without this signature, the invoice would not be valid for the tax authorities.
How to open the invoice .p7m file
Opening the file means extracting the XML invoice from the signed envelope. With P7M Viewer just a few steps are enough:
1. Open the Open .p7m tool.
2. Upload the invoice .p7m file.
3. View or download the original invoice.
No programs to install, and for a single file it's free. See also who signed and when.
.p7m, .xml and .pdf: what's the difference
- .p7m — the digitally signed invoice (the one you receive);
- .xml — the actual invoice, once extracted from the .p7m;
- .pdf — a readable version that you can create by printing the invoice.
Open it from your computer or smartphone
The online method works everywhere: Windows, Mac, Android and iPhone. On Android there is also the free P7M Viewer app, convenient for quickly opening invoices received via email.
Frequently asked questions
Is the .p7m file a virus? No, it's simply a digitally signed invoice.
Can I open it for free? Yes, opening a single .p7m file is free.
What exactly does it contain? The invoice in XML plus the digital signature of the person who issued it.
In summary
The .p7m file of the electronic invoice is the XML invoice enclosed in an envelope with a digital signature, necessary for its legal value. To open it, just upload it to P7M Viewer and extract the invoice in a few seconds, for free.
