Sending a fax with your Free, Orange, SFR or Bouygues box

Short answer: in 2026, none of the four big French providers offers an integrated fax service as part of a consumer plan any more. Only one thing is left: the box's phone socket, into which a fax machine can still be plugged — successfully in most cases with Free and Orange, more hit-and-miss with SFR and Bouygues Telecom, and never without adjusting the settings (speed lowered to 9,600 bit/s, ECM error correction disabled, device plugged straight into the box with no extension cable or leftover ADSL filter). The old in-house "online fax" services, sending from the customer account area, and the fax numbers bundled with a subscription have all been discontinued. If your box refuses to fax — and that happens often — the solution that works in ten minutes, with no hardware, is sending from a computer or a phone to the fax number of the public office you are dealing with.

Why a fax struggles over a box

A fax machine was designed for an analogue line: it speaks in modulated whistles, within a narrow frequency band, and it assumes the channel is stable end to end. The box, on the other hand, does voice over IP: it chops the signal into packets, sends them over the internet, then reassembles them. As long as it is human speech, a lost packet goes unnoticed — the ear fills in the gap. For a fax, that same loss breaks the synchronisation between the two machines: truncated page, black band, disconnection mid-transmission, or a transmission report announcing "failure" after three attempts.

Two mechanisms exist to work around this problem:

• G.711 passthrough: the box carries the fax sound as is, like uncompressed voice. It works if the connection is clean and lightly loaded. This is what most consumer boxes do.
• The T.38 protocol: the box (or the provider) decodes the fax, transports it as data, then replays it at the other end. Far more robust, but in practice reserved for business plans and corporate telephony operators.

In other words: on a consumer box, you are gambling on passthrough, and your success rate depends on your upload speed, the quality of your network and, sometimes, on the fax machine at the other end.

Free: the Freebox phone socket, with conditions

The Freebox has historically been the one that handles a fax machine best. The phone socket (RJ11, on the back of the Server) accepts a fax plugged in directly, and the provider's user forums have been confirming successful transmissions to French numbers for years, provided you throttle the device.

What has changed with recent Freebox generations: fibre subscribers depend entirely on IP quality, with no copper line as a backup, and certain power-saving or call-filtering settings in the subscriber account area interfere with the initial negotiation between the two fax machines.

The three settings to change before any attempt, in the fax machine's menu:

A short RJ11 phone cable in good condition, plugged directly into the box, often changes the outcome all by itself: six-metre extension cables and old ADSL filters left in the wall are the two leading causes of failure we see reported.

Worth noting: the "Fax to mail" option / receiving faxes by email that existed in the past with some providers has no active equivalent in Free's 2026 plans. To receive, you need to go through a digital fax number — that is the subject of our guide on the virtual fax number.

Orange: the Livebox allows it, but Orange guarantees nothing

Orange remains the incumbent operator, and it is also the one that has communicated most about the end of the copper network. Its position has been clear since the gradual technical shutdown of the PSTN: the analogue telephony that fax machines relied on is no longer sold, and fax over IP is not guaranteed on consumer plans.

In practice, the Livebox phone socket works in the majority of cases for a one-off transmission to a French number, with the same settings as above. However:

• Orange does not provide troubleshooting support for "my fax no longer goes through" on a residential plan;
• premium-rate numbers and certain short numbers cannot be reached from the box, which makes no difference for public offices but does for some commercial services;
• on the business side, Orange's corporate telephony plans do offer T.38 and genuine support — that is the only reliable route if you fax every day.

If that is your situation, re-read what we wrote about the end of the PSTN and the migration of analogue fax lines: the hardware question comes before the choice of provider.

SFR and Bouygues Telecom: more hit-and-miss, and no more fax service

With SFR, searching for "send a fax over the internet SFR" still leads to old services for sending faxes from the customer account area, which no longer exist. What remains is the phone socket on the SFR box, with a success rate users describe as uneven depending on the generation of the unit and on whether you are on leftover ADSL or on fibre. Short transmissions (one or two pages, black-and-white text, no photos) go through more reliably.

With Bouygues Telecom, it is the same story: the Bbox has a phone socket, the provider does not document fax use and offers no guarantee. The business plans from either company may include properly managed fax over IP, but you have to ask the sales rep explicitly and have it written into the contract — "the box has a phone socket" is not a fax service commitment.

One last thing all four providers have in common: porting a fax number remains possible to a digital fax provider, but not always to another box. If your fax number appears on letters, contracts or a letterhead, treat it as an asset to be migrated — we set out the method in the article on business relocation and fax number continuity.

The six-minute diagnosis

Before concluding that "it doesn't work", run through this sequence. It eliminates 80% of failures.

1. Plug the device in directly to the box's phone socket. No extension cable, no splitter, no ADSL filter.
2. Pick up the handset of the fax machine (or of a phone on the same socket): you should hear a clear dial tone. No dial tone = a box or subscription problem, no point going any further.
3. Lower the speed to 9,600 bit/s and disable ECM.
4. Run a print self-test to check that the paper and toner are not the culprits (a black band can come from the scanner glass, not the network).
5. Send a test page to a number you are sure of, in the middle of the day but outside peak hours (avoid 6 pm–9 pm, when your upload bandwidth is shared).
6. Read the transmission report: it shows the number of pages sent and the speed actually negotiated. It is your only proof of sending, and it is also your diagnostic tool.

If step 5 fails three times with correct settings, it is no longer your device: it is the IP transport. Persisting is pointless.

When the box isn't enough: the three ways out

1. An ATA adapter with T.38 support

An analogue telephone adapter (ATA) sits between the fax machine and the network, and handles the conversion to T.38 itself with a SIP provider that supports it. This is the solution for practices and small organisations that want to keep their machine. Budget for a unit, a SIP subscription, and a good half-hour of configuration — best reserved for those who fax regularly.

2. An all-in-one with automatic duplex scanning

If you are keeping a device, it may as well be used mainly for scanning: an all-in-one laser printer with an automatic duplex feeder turns a thirty-page file into a clean PDF in a minute, which is exactly what you need for digital sending. The fax module becomes incidental. For bound documents or booklets, an A4 flatbed scanner usefully rounds out the setup.

3. Sending from a computer or a phone

This is the simplest way out, and the one that depends neither on the box, nor on the provider, nor on the time of day: you upload a PDF, you enter the French destination number, you receive a confirmation of sending. No hardware, no speed settings, no dial tone to listen for. Our pricing and FAQ pages explain how it works, and the directory lets you check the fax number of the public office you are dealing with before sending — a single wrong digit costs more than a technical failure.

Preparing a document that gets through, whatever the channel

Whether it leaves from a fax machine plugged into the box or from a computer, a fax is still a black-and-white image at 200 dots per inch. Three habits markedly improve legibility at the other end:

• No coloured background, no highlighter: yellow vanishes, light blue turns dirty grey. A fine-tip black marker to annotate a document, and nothing else.
• White paper, not cream recycled stock: scanning contrast collapses on tinted paper. A ream of 80 gsm white paper is all you need.
• A clear cover sheet with recipient, subject, file reference and number of pages. Our cover sheet generator produces one from three fields, and the PDF assembly tool puts the file in the right order before sending.

Finally, keep a record: the fax machine's transmission report or the digital confirmation of sending, filed with the document you sent. Faced with a court registry or a public finance office, that is the document that proves the date — not your memory of having done it.

Frequently asked questions

Does my box subscription include a fax number?

No. The box subscriptions of 2026 include a landline telephony line with a number, not a separate fax number. A fax machine plugged into that socket will send and receive on the same number as your phone, which forces you to choose between answering calls and letting the machine pick up.

Why did my fax go through before and not now?

Three classic causes: your line has moved from copper to fibre (the analogue signal no longer exists physically), a change of box altered the codecs used, or an update re-enabled ECM on your fax machine. Go back through the diagnostic sequence above.

Is T.38 available on a consumer plan?

Rarely, and never contractually guaranteed. T.38 is found on business telephony plans and with SIP providers. On a residential box, assume you are on passthrough and set your device accordingly.

Can I fax abroad from my box?

Technically sometimes, but it is fragile and billed outside your plan depending on the destination. Our sending form, for its part, is limited to French numbers: that is the site's scope. The constraints of sending outside France are described in our dedicated article on faxes abroad.

Should I keep my old fax machine?

Only if you use it to receive faxes and the box accepts them. For one-off sending to a public office, digital sending is faster, more legible and produces cleaner proof than a thermal receipt that will fade within two years.

In summary

• No French provider offers an integrated fax service any more in 2026: all that is left is the box's phone socket.
• Free and Orange work most of the time for a one-off transmission; SFR and Bouygues Telecom are more hit-and-miss. None of the four guarantees the service on a consumer plan.
• The three settings that save a transmission: 9,600 bit/s, ECM disabled, device plugged directly into the box.
• T.38 (reliable) is reserved for business plans and SIP providers; on a residential box, you are on passthrough.
• After three failures with correct settings, the problem is the IP transport: switch to sending from a computer or a phone.
• In every case, check the fax number before sending and keep the proof of transmission: that is what counts when a deadline is at stake.