Have you received an electronic invoice with a .p7m extension and your computer cannot open it? It's a common problem: the digitally signed electronic invoice is enclosed in a .p7m file that normal programs cannot read. In this guide we will see how to open an electronic invoice in .p7m format quickly and easily.
Because the electronic invoice is a .p7m file
The .p7m file is a PKCS#7 (CAdES) cryptographic envelope that contains the actual invoice — an XML file — along with the digital signature** of the person who issued it. The signature serves to guarantee two fundamental things for the Exchange System (ES):
- authenticity — who actually issued the invoice;
- integrity — that the invoice has not been modified after signature.
This is why your PC shows an "unknown" file: it sees the signed envelope, not the invoice inside.
How to open a .p7m electronic invoice online
The quickest method does not require any programs to install and works on Windows, Mac, Android and iPhone:
1. Open the Open .p7m tool of P7M Viewer.
2. Drag the invoice .p7m file, or tap Choose File.
3. In a second the original invoice is extracted.
4. View the invoice or Download the XML file.
P7M Viewer also shows you who signed the invoice and when, so you know immediately that the document is authentic.
What about files with a double .xml.p7m extension?
Electronic invoices often have names like `IT01234567890_00001.xml.p7m`. It means that the internal document is the invoice in XML format, then signed (hence the external .p7m). P7M Viewer automatically recognizes the content and returns you the correct .xml file.
Do not rename the file
A common mistake is trying to rename the invoice from .p7m to .xml or .pdf. It doesn't work and you risk corrupting the file, because the signature envelope remains in place. Always use a tool that extracts the invoice, rather than renaming it.
Open the .p7m electronic invoice from your phone
Do you receive invoices via email or do you download them from the tax drawer while you are out and about? With Android you can install the free P7M Viewer app and open the invoice with a tap, or use the site from your browser. On iPhone, open the site with Safari and choose the file from Files or iCloud.
Frequently asked questions
Is opening a .p7m invoice free? Yes, opening a single .p7m file is free and without registration.
Do I have to install a program? No, everything happens in the browser. On Android you can also use the free app.
Is my data safe? The file is processed only to extract the invoice and then automatically deleted.
In summary
Opening an electronic invoice in .p7m format is simple: upload the file to P7M Viewer and view or download the original invoice in a few seconds, on any device and for free.
