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Fax explained

Proving you sent a fax: which documents to gather, and how to keep them

The legal weight of a fax is argued before a judge. The proof, however, is prepared beforehand: on the day of sending, with three documents that people almost always forget to put together.

Short answer

Sending a fax is proved with three documents kept together: the document exactly as it was sent, a dated record of its transmission to the recipient's number (transmission report or acknowledgment) and proof that this number was the right one. None is enough on its own. The fax then generally counts as a starting point of proof, which the judge weighs with the rest of the case.

Building the proof, in four steps

  1. 1

    Freeze the document you sent

    Keep the exact PDF you transmitted, without editing it afterwards. If it is a scan of a signed original, keep the paper original too: the fax proves the transmission, the original proves the content.

  2. 2

    Get a dated record

    On this site, the PDF transmission acknowledgment (optional, €3.99 incl. VAT, charged only if the fax goes out) gives the date and Paris time, the number dialled, the number of pages and a unique acknowledgment number. The free confirmation email adds to the record without replacing it.

  3. 3

    Prove the number was right

    Take a dated screenshot of the recipient's official web page, or keep the letter showing their fax number. A perfect transmission to the wrong number proves nothing useful.

  4. 4

    File everything together

    One folder per sending, named by date and recipient, containing the document, the acknowledgment and the proof of the number, in two copies on two different media. Keep it for as long as a dispute is possible: in French civil matters, the general limitation period is five years.

Proving sending is not proving receipt

Disputes are almost always about receipt: “I never received anything.” A transmission report shows that a machine answered the number dialled; a transmission acknowledgment dates the sending to that number. Neither proves that a person read the document. When a rule requires registered post, or when the stakes are high, back the fax up with a registered letter or ask the recipient for a written acknowledgment: their reply is the best proof of receipt.

Frequently asked questions

What is the difference between a transmission report and a transmission acknowledgment?
A transmission report is the technical record a fax machine produces at the end of the call: time, duration, pages confirmed by the remote machine. This site's transmission acknowledgment is a PDF document attesting the transmission of the fax to the number entered, time-stamped, with sender, recipient, subject, pages and a unique number. Both date the sending; neither proves it was read.
Is a screenshot of the confirmation page enough?
It is better than nothing, but it is the easiest piece to challenge: it carries no acknowledgment number and no details of the sending, and it is easily altered. Prefer a PDF issued by the service, kept as it is, together with the document sent.
How long should I keep proof of a fax?
For as long as a dispute is possible. In French civil matters, the general limitation period is five years from the day the facts became known; some areas have their own periods, shorter or longer. Since the acknowledgments are PDFs, download and file them yourself rather than relying on a link received by email.

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The form fits on one page: a PDF, a recipient and a return address. No account, no card: one-page faxes are free and unlimited.

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