L'équipe Texto SMS Gratuit
19 September 2026 · 12 min read
Introduction: four hours of silence, on a Tuesday morning
You signed up online on Sunday evening. The new carrier announced that "your number will be transferred within 3 working days". Tuesday, 9:12 a.m., no signal at all: the old SIM displays "No service", the new one isn't active yet. By 1:40 p.m., everything is back. In between, two missed work calls and a banking verification code that never arrived.
Nothing abnormal about it: that is exactly how mobile number portability works in France. The problem is that nobody told you when the outage window would open, or what happens if the port fails.
Portability is a right, it is free, and it is governed by the French Postal and Electronic Communications Code and by the rulings of Arcep. Several million lines use it every year in France, and it is what makes the mobile market so competitive: switching carriers without changing your number is what lets you cut your bill without telling a single contact. This guide describes how it really works, step by step, and above all what to do when things go wrong.
What portability really is (and what it does to your old contract)
Two things to keep in mind before anything else:
- Porting counts as cancellation. You don't need to cancel with your old carrier: the porting request automatically terminates the line being ported. Sending a cancellation letter as well is not just pointless, it's dangerous — a cancellation that takes effect before the port releases the number, and a released number can no longer be ported.
- The new carrier handles everything. You never contact the old one to arrange the transfer. The new carrier (the "recipient operator") manages the request with the "donor operator".
Golden rule: never cancel a line yourself if you want to port it. Sign up elsewhere, and the cancellation takes care of itself.
A corollary: if your contract still had a commitment period running, porting doesn't wipe it out. The remaining months, or the early termination fee (at most a quarter of the remaining monthly payments beyond the 12th month for a 24-month commitment, under the Chatel law), will appear on your final bill. That is not a porting fee — that kind of charge is banned.
Step 1: getting your RIO code
The RIO (Relevé d'Identité Opérateur, or operator identity statement) is the 12-character identifier attached to your line. It proves you are the account holder and tells the system which number to port.
There are three ways to obtain it:
- The free 3179 voice service, dialled from the line in question. This is the universal route: every French mobile operator is required to offer it. The code is read out and then sent by text message.
- Your online account with the carrier, usually under the contract or cancellation section.
- A text message to 3179 with most carriers, using the word "RIO".
A few things that trip people up in practice:
| Situation | What you need to know |
|---|---|
| Phone lost or stolen | 3179 can't be reached from the line: go through your online account or customer service, with proof of identity. |
| Line suspended for non-payment | The RIO can still be issued, but porting may be refused until the debt is settled. |
| Business line in your company's name | The account holder must be identical on the recipient side, otherwise the request fails every time. |
| Capped plan or prepaid card | Porting is possible, including from a prepaid line, as long as the line is active. |
The RIO has a shelf life: it remains valid as long as the line's status hasn't changed, but recipient operators often reject a code that is more than a few weeks old. Get it on the day you sign up, not three months beforehand.
Step 2: signing up and the three-working-day deadline
You give the new carrier: the number to port, the RIO, your identity details and your bank details. Once the request has been sent, the legal porting deadline is one working day, extended to three working days maximum in common commercial practice — the key point is that you can request a later porting date if you wish, which is very useful if you're travelling.
The important word is working: Saturday counts, Sunday and public holidays don't. So signing up on a Friday evening means a port on Wednesday at the latest, not Monday.
The outage window
On the day itself, the transfer usually takes place between 8 a.m. and 4 p.m., excluding weekends. During that period:
- the old SIM card stops working;
- the new one activates, sometimes several hours later;
- incoming text messages during the switch can be permanently lost — including banking authentication codes.
This is the most common cause of nasty surprises. Two concrete precautions:
- Don't port on a Tuesday morning if you're expecting an electronic signature or a transfer to approve that day. Pick a quiet date.
- Temporarily move your authentication to an authenticator app (TOTP) or to email rather than SMS for the duration of the switch. Codes sent by text during the window are not resent.
If you make a lot of calls for work, a cheap backup phone kept in a drawer with a prepaid SIM solves the problem once and for all: you stay reachable on a secondary number during the outage and whenever the network goes down.
Step 3: receiving and activating the new SIM
Two scenarios, very different in 2026.
Physical SIM card
It arrives by post, often within 48 to 72 hours. The classic trap: the card hasn't arrived on the porting day, and you're left without a line. This is why most carriers only trigger the port once the SIM has been declared activated — check that this is the case, and if it isn't, ask for a porting date after the card arrives.
Think about the format too: almost every recent handset uses a nano-SIM, but if you're reusing an older device or a 4G router, a SIM card adapter will stop you being stuck with a card rattling around in the tray.
eSIM
The eSIM changes everything: no waiting for the post, activation via QR code or from the carrier's app, in a matter of minutes. All the major French operators and a good share of MVNOs now offer it. Two advantages when porting:
- you can set up the eSIM profile before the porting day and activate it when the switch happens;
- on a dual-SIM handset, you keep the old physical SIM active alongside it until the switch, which reduces the outage to a few minutes.
One word of caution, though: the eSIM is tied to the device. If you change phones, you have to request a new profile, sometimes at a charge after the first one. And a handset bought outside Europe may not accept French operators' eSIM profiles.
The six reasons a port fails
When a port is rejected, the recipient operator often sends a terse message along the lines of "request unsuccessful". In almost every case, one of these six reasons is behind it.
- Wrong or expired RIO. One mixed-up character (O/0, I/1) is enough. Request the code again from 3179 and resubmit.
- Account holder mismatch. The name and date of birth declared with the recipient must match those on the donor contract. The typical case: a line opened in a spouse's name. You then need to transfer the account holder before porting — a free and quick operation with most carriers, but one that requires both parties' agreement.
- Line already cancelled. This is the fatal mistake mentioned above. Once the line is closed, the number returns to the common pool after a quarantine period and becomes unrecoverable. There is no remedy.
- Non-portable number. Machine-to-machine numbers, certain technical numbers and lines attached to a locked corporate fleet cannot be ported individually.
- Outstanding unpaid bill. The donor operator can refuse on the grounds of an unsettled invoice.
- A porting request already in progress. Two simultaneous sign-ups with two carriers block everything: cancel one, wait for the system to clear, then start again.
When the line stays silent: your options
If the 4 p.m. window has passed on the porting day and you still have neither calls nor texts, act in this order.
The first 24 hours
- Restart the phone, test the SIM in another handset, check manual network selection (Settings → Connections → Mobile networks → Manual selection). A properly activated SIM will find the network.
- Call the new carrier's customer service, not the old one's, and explicitly ask for the status of the porting order and its actual porting date. Note down the case reference number.
After 48 to 72 hours
- Send a written complaint to customer service, via the online account form or by registered post. Mention the sign-up date, the RIO used, the case reference, and demand a firm porting date.
- Claim the compensation provided for in your contract: French operators' terms and conditions provide, in application of the rules on portability, for compensation in the event of a delay or service interruption attributable to the operator. It is almost never paid out spontaneously.
After a month with no answer
- Contact the consumer department, then, a month later, the Médiateur des communications électroniques (the sector ombudsman, free of charge, with an online submission form). This is the step that resolves the largest number of cases.
- Report the failing to Arcep, which collects user alerts through its "J'alerte l'Arcep" platform. Arcep won't settle your individual case, but its portability statistics feed into its supervision work.
- In parallel, a consumer association such as UFC-Que Choisir or CLCV can back up your complaint. A practical guide to consumer rights helps you word your letters in the right terms.
Preparing for the switch: the 48-hour checklist
A successful port comes down to a handful of things done beforehand, not afterwards.
- Back up your contacts. In 90% of cases they live in your Google or iCloud account, but not the ones stored on the old SIM. Export those first.
- List the services linked to your number: bank, tax office, insurance, delivery platforms, messaging apps. The number doesn't change, but SMS two-factor authentication is interrupted on the day.
- Check your remaining usage. Data, out-of-plan minutes, add-ons: everything used before the switch will appear on the old carrier's final bill.
- Check your direct debit. A final bill almost always arrives after the port, sometimes a month later. Don't cancel the direct debit mandate straight away: a rejected payment means fees and a non-payment flag.
- Keep the old SIM for two or three weeks in a SIM card storage case, rather than destroying it. It's no longer of any use, but if the port fails and you have to start over, its history helps prove the timeline.
- Photograph or archive the sign-up confirmation, the RIO and the announced porting date. In a dispute, the burden of proof hinges on those dates.
Locked handsets and hardware
One last point that is often forgotten: porting transfers a number, not a phone. In France, handsets sold by carriers can no longer be network-locked from the moment they are put into service — unlocking is free and immediate, including for a subsidised device. If your phone refuses the new carrier's SIM, in most cases it's a device bought outside France or second-hand from a private seller.
Two useful checks before the switch:
- Confirm frequency band compatibility, particularly if you're moving to a different network. An imported device may not support the 700 MHz band, which is widely used in France for rural coverage.
- If you're also picking up a refurbished handset, do it before the port, not during: two variables changing on the same day make diagnosis impossible. A good-quality USB-C mains charger and a protective case are part of the same purchase — better to have them before you start using the phone.
Conclusion: the right exists, the timing is yours
Portability is one of the most consumer-friendly mechanisms in the French mobile market: free, automatic, it counts as cancellation and wraps up within a few working days. Its only two genuine pitfalls are practical ones: never cancel the line yourself before porting it, and choose the switch date according to how reachable you actually need to be, rather than leaving it to chance.
The rest — RIO from 3179, checking the account holder, preparing the eSIM, a written complaint and then the ombudsman — is simply a sequence of orderly steps. Follow them in order, keep a record of the dates, and switching carriers goes back to being what it should always be: a simple adjustment to your bill.
Key sources
- Arcep: rulings and observatory on number portability, plus the "J'alerte l'Arcep" platform.
- Médiateur des communications électroniques: free submission after a written complaint has gone unanswered.
- Code des postes et des communications électroniques: articles on number retention and porting deadlines.
- DGCCRF: information on termination fees and commercial practices.
- UFC-Que Choisir, CLCV: template letters and support in disputes.
