This process is patented by POPFAX, French company with registered office located at 3, passage des bleuets, 78420 Carrières sur Seine – France and registered at the Trade Court of Versailles, registration number: (RCS) 443 336 136.


The service has been publicly released and advertised worldwide via Internet on 25th of January 2010.

Description of the service

The technical process called as a whole hereinafter "registered fax" (« fax recommandé » in French) consists in sending an electronic document by fax where both the content is certified and the delivery to the recipient is guaranteed.

It serves the purpose of creating legal evidence that unalterable information has been shared between the sender and the receiver of the registered fax.

The functional principle is as follows:

Process functional scheme

The functional chart below illustrates these steps:

The following table defines the items to which each party in the registered fax process has access:

Sender Receiver Service Provider
Signed PDF X X
Signature X X
Fax with printed appendix X
Transmission report X
Read notification X
Long term archive X X

Hereafter is a display of the appended page as it is at the first commercial launch.

Empty registered fax advice
(as it is appended at the end of the signed document that is available to all parties)

Advice page containing the identification codes for the receiver and a print of the signature
(this version is only available on the destination fax)

The archived documents that are downloadable by the parties are in the following formats:

Compressed Folder downloadable by the sender from within his account:

The files contained in the compressed folder of the sender are separately downloadable by the receiver:

The "sgn" file contains the digital signature (the same character string as the one printed on the document received by the fax machine of the receiver)