Guide · Digital signatures
How to open a .p7m file
Received contract.pdf.p7m or invoice.xml.p7m and nothing on your computer opens it? A .p7m file is the original document sealed inside a digital-signature envelope. MSGView opens the envelope right in your browser, gives you the original PDF or XML back and shows what its signing certificate says — no signature software to install and nothing uploaded.
Open a .p7m file in 3 steps
- Open MSGViewGo to msgview.app in any browser — Windows, Mac, Linux, iPhone or Android. Nothing to install, no account.
- Drop the .p7m fileDrag the file onto the page. .pdf.p7m, .xml.p7m, double-signed, base64, .tsd and .m7m files all work. It is read in your browser and never sent to a server.
- Open or save the documentMSGView takes the original document out: a PDF opens with one click, an XML invoice saves to your computer. Above it you see the name, organisation and tax ID written in the certificate.
What is a .p7m file?
A .p7m file is a document with a CAdES digital signature: the original file (a PDF, XML or Word document) is wrapped together with the signer's certificate. That is why the name has two extensions, like document.pdf.p7m — the PDF is inside. They are everywhere in Italy: e-invoices (FatturaPA), certified email (PEC) and documents from public offices, courts and notaries.
Your computer cannot open it only because it does not know the .p7m extension; the file is not damaged. Once the envelope is removed, what is inside is an ordinary PDF or XML.
Signature read, not verified — and why we say so
MSGView shows what the certificate inside the file says: name, organisation, tax ID, the issuer it names and the signing date. It checks nothing: not the signature (not even cryptographically), and not the certificate — anyone can create a certificate with any name in it. A real check needs a cryptographic verification against the list of trusted certification authorities; use your signature software or your provider's verification service for that.
Private by design
Invoices, contracts and official letters carry personal and business data. Most “open p7m online” sites ask you to upload the file to their server. MSGView does not: the file is opened in your browser's memory and never leaves your device — you can confirm it in your browser's Network panel.
FAQ
How do I open a p7m file without software?
Drop the .p7m file on msgview.app. Your browser removes the signature envelope and gives you the original document (PDF or XML). Nothing to install.
My file is signed twice (.p7m.p7m). Does it work?
Yes. MSGView opens up to four nested envelopes and lists every certificate.
What is the difference between .p7m and .p7s?
A .p7m holds the document and the signature together. A .p7s is a detached signature: it only contains the certificate, and the document is a separate file. MSGView shows what the certificate says for .p7s files too.
What about .tsd and .m7m files?
Both are a .p7m with a time-stamp added. MSGView opens them too: a .tsd directly, an .m7m as a bundle whose .p7m you open with one click.
Does MSGView check that the signature is valid?
No. It shows what the certificate says, but checks neither the signature (not even cryptographically) nor the certificate. Use your signature software for a real check.