Choosing between SMS and fax

One warns, the other delivers and proves.

Lining up SMS and fax gives a simple picture: a doorbell on one side, a letterbox on the other. An SMS warns a person, on the screen they look at dozens of times a day; a fax, for its part, deposits a complete page — stamp, signature, table and all — on an organisation's machine, and the remote device confirms delivery. So the real criterion is not speed but the nature of the send: a simple alert, or a document whose transmission may one day have to be justified? Often the best answer is to run the two channels back to back.

Four differences that matter

On speed, the two channels are on a par. Here is what really separates them.

What is transmitted
An SMS carries only a few words of plain text. A fax reproduces an A4 page exactly as it is: layout, ticked boxes, signatures, company stamp. Elements that lose their meaning as soon as they are recopied as text.
The record left behind
An SMS acknowledgement stays in the operator's systems and attests only to an arrival on a phone. A fax produces a report that records the number dialled, the time-stamp and the number of pages accepted by the remote device.
Who you are addressing
An SMS reaches a person, on their own number. A fax addresses an organisation: a town hall's reception, a court registry, a hospital pharmacy — the number comes from an official form.
The expected channel
No administrative procedure admits a document submitted by SMS. The organisation that publishes a fax number has built its reception on that channel: the sender complies.

When an SMS is enough

  • Alert, don't deliver

    Confirming an appointment, reporting a delay, saying “the quote has gone out by fax”: an SMS is read almost immediately. It announces the document without ever replacing it.

  • Contacting an individual

    Plumber, neighbour, distant relative: none owns a fax. For those people, a text or an email carrying the PDF is still the obvious choice — and the only option that works.

  • When nothing is disputed

    A gate code, an address, a delivery time: when nothing will ever require proof, convenience comes before the record. That is the lot of most everyday messages.

When fax is required

  • The organisation requires it

    Health insurance, court registry, hospital department, notary's office: many still process on faxes. Sending them the document another way is to risk it sitting in a queue.

  • A page, not a line of text

    Signed order, prescription, minutes or certificate: their strength lies in their very presentation. A photo sent by messaging gives neither the right framing nor legibility sufficient for the receiving department.

  • A deadline to meet

    Termination, complaint, file to submit before a date: keep the PDF you sent and its transmission report. Together, they attest the content, the number dialled and the time — three things no SMS proves.

The right method: fax, then warn

The weak spot of fax is the machine that receives: a shared device at the end of a corridor or sitting at reception, where the sheet can wait for hours. An SMS or a phone call just after the send settles the problem: the right person learns that something awaits them and heads over to pick it up.

The reverse order is worthless. Warning by SMS does not carry the document, and the so-called “SMS fax” services do no more than send a link where the file can be downloaded. No fax, no report: nothing a counter could record as a delivery.

SMS and fax: frequently asked questions

Does an SMS have evidential value?
Yes, whenever the law allows free evidence, on the same footing as an email or a fax. The weighting is then for the judge, case by case: you still have to show who wrote it and its exact content. To settle a specific case, consult a legal professional or a lawyer.
Can I get an SMS alert when a fax arrives?
That is a feature of some reception services, backed by a virtual number: the provider captures the fax and sends you a notice. Faxeroo limits itself to sending and allocates no number; the reception page reviews the solutions.
Can a fax be sent to a mobile?
No. It would take a fax machine at the other end answering with tones, and the cellular network damages those signals. The subject is covered on our dedicated fax-and-mobile page: the technical reasons and alternatives are detailed there.

Fax in everyday life

This topic

Keep reading

Pages chosen to help you prepare a send, track it, or keep proof of it.

See also