Short answer: porting a number normally generates between five and fifteen texts in 72 hours — RIO code, acknowledgement of the request, switch date, SIM activation, connection settings, end of contract with the former carrier. These messages come from short codes or named senders, never ask for a bank card and almost never contain a single-use link. Any message demanding a payment "to complete the transfer" is fake.
Updated 11 November 2026.
Changing carriers while keeping your number has become a matter of minutes: you dial 3179 to get your RIO, enter it with your new carrier, receive a SIM card or an eSIM QR code, and the line switches over. While all that happens, your phone becomes very chatty.
And this is precisely the moment scammers love. Not because they know you are switching carriers — most of the time, they have no idea — but because for two or three days you are in a frame of mind where a technical text from your carrier looks perfectly normal. You are expecting messages. You read them quickly. You click.
Which texts do you normally receive during a number port?
The ones that accompany each administrative and technical step of the switch. They are short, impersonal, and ask nothing of you beyond, at most, restarting your phone.
Here is the typical sequence, in the order it unfolds:
| Step | Usual sender | Expected content |
|---|---|---|
| RIO request | short code of the carrier you are leaving (often in a 3xxxx range) | your line identity, 12 characters, and the seniority date |
| Order registered | brand name of the new carrier | summary, order number |
| Porting date | brand name of the new carrier | "your number will be transferred on … between 7 a.m. and 1 p.m." |
| Cancellation confirmation | former carrier | end of contract, balance, date of final bill |
| Line activation | new carrier | "your SIM is active", sometimes an activation code |
| Data/MMS settings | technical short code | automatic configuration to accept |
| Customer account | new carrier | username, password creation link |
Two useful notes. First, the RIO code does indeed arrive by text after a free call to 3179: it is a regulated procedure, described by Arcep (the French electronic communications regulator) and common to every carrier. Second, at Free Mobile a good share of service messages goes through the short code 2030, which is a legitimate sender for the carrier and one of the most frequently searched queries among subscribers who wonder about it.
If you want to understand the general logic behind these four- or five-digit senders, our guide on breaking down a short code or an alphanumeric sender details the ranges in service in France.
Why does the former carrier keep writing after the cancellation?
Because the contractual relationship does not end on the day of the switch: there is still a closing bill, sometimes a refund, often equipment to return, and always a desire to win you back.
In practice, in the following weeks, three kinds of messages from your former carrier are normal:
- closing messages: final bill, credit or debit balance, refund method;
- logistics messages: return of a subsidised phone, a router, a set-top box, with a shipping slip;
- win-back messages: "come back to us, 3 months at €5", which count as commercial prospecting.
The first two are contractual and do not require your consent. The third does: it must include a way to opt out, usually "STOP to …". If the follow-ups continue after a STOP, objecting to marketing falls under the GDPR and prospecting rules, and the CNIL (French data protection authority) accepts complaints online.
One practical detail people often forget: before the switch, remember to retrieve the texts from your old voicemail and the backup codes for your accounts. A simple spiral notebook in your desk drawer, where you copy single-use recovery codes by hand, remains more reliable than a message thread you are going to wipe when you change phones.
Which texts are fakes during a carrier change?
The ones that add a step that does not exist: a payment, an identity check via a link, a "porting validation" on a website, or forwarding a code received elsewhere.
The recurring scenarios seen in France are fairly stable:
"Your number port is blocked. Settle the €1.90 transfer fee to activate your line: [link]"
There is no porting fee in France: keeping your number has been free since the loi Chatel (Chatel Act) and the successive decisions of Arcep. The tiny amount is not there to make the scammer €1.90 richer: it is there to capture a complete card number, with expiry date and security code.
"Your new SIM could not be activated. Confirm your identity: [link]"
A failed activation is sorted out with the carrier, in your customer account or over the phone — never through a form received by text.
"SFR: €112 overpaid on your closed contract. Provide your IBAN for the refund: [link]"
A credit balance is refunded to the payment method already on file, or by cheque. A carrier never asks for an IBAN again by text.
And the most dangerous one, because it lands in exactly the window when you are expecting it:
"Porting confirmation code: 48213. Give it to the adviser to complete the transfer."
No code received by text should ever be passed on to anyone, including someone who calls you claiming to be your carrier. That is the basic mechanism of line hijacking — a subject we covered in detail in our article on the calls that come immediately after a code arrives.
Why is this period an attack window for SIM swapping?
Because, from the network's point of view, changing carriers is exactly what a SIM swap attack does: a number leaving one piece of hardware for another.
During a legitimate port, it is normal for:
- the line to be cut off for a few minutes to a few hours;
- calls to be abruptly diverted to a different voicemail;
- banking or authentication texts not to arrive during the switch.
During an attack, the symptoms are the same — which explains why many victims take hours to work out what is happening. The difference is simple: you know whether you requested the port. If your line goes down without you having asked for anything, and a text announces a "migration" or a "SIM update", that is not a technical operation, it is probably a stolen number. Call your carrier from another phone immediately. We described the full mechanism in SIM swapping and eSIM: how your number can be stolen.
Two concrete precautions that cost very little:
- Move critical authentication off text messages before changing carriers. An authenticator app, or better still a FIDO2 USB-C security key kept with your paperwork, does not depend on your SIM card and therefore survives any switch.
- Keep the old SIM for a week, in a SIM card holder rather than at the back of a drawer: if the port fails, it sometimes becomes usable again, and it is also evidence in case of a dispute.
How can you check that a text really comes from your carrier?
By looking at three things, in this order: the sender, the link, and the nature of the request. If any one of the three is shaky, don't click.
The sender. French carriers use either a four- or five-digit short code, or an alphanumeric sender (ORANGE, SFR, BTELECOM, etc.). Careful: a sender name can be spoofed, and the fake message sometimes appears inside the genuine conversation thread. That is a documented reality, not a myth: see sender spoofing explained in detail. So the sender is a clue, never proof.
The link. Legitimate domains are short and free of fanciful subdomains: orange.fr, sfr.fr, bouyguestelecom.fr, free.fr, mobile.free.fr. Anything that looks like orange-portabilite-client.net or a URL shortener should be dismissed. When in doubt, don't open the link: type your customer account address by hand.
The request. Here is the rule that settles 95% of cases:
| What a carrier can ask by text | What it never asks for |
|---|---|
| Restarting your phone | A bank card number |
| Accepting automatic settings | An IBAN |
| Calling back a short code or customer service | The code received by text |
| Logging in to your customer account (address typed by hand) | Your credentials entered in a form sent via a link |
| Noting down a switch date | A "transfer fee" |
What should you do with a suspicious text received during the switch?
Report it to 33700, then delete it — without replying, without clicking, without calling back the number displayed.
The official procedure is the same for every carrier:
- Forward the message to 33700 (free service, aside from the cost of one text for subscribers with unlimited texts).
- You will receive a request for details: send back the sender's number exactly as it appears, in a single text.
- If the message has already led you to enter banking details, contact your bank to block the card, then file a complaint. The national system for reporting fraudulent content is available via cybermalveillance.gouv.fr.
Our dedicated page on reporting text spam to 33700 covers the accepted formats in detail. And to understand what happens to a report once it is sent, we followed the full journey in You forward a suspicious text to 33700: what happens to your report?.
A word about blocking: blocking the sender of a fake porting text achieves almost nothing, because these campaigns run on disposable numbers. Blocking works against a person, not against a campaign — a distinction we detail in what blocking a number really stops.
And afterwards? The spike in marketing texts that follows a new subscription
It is normal, it is legal, and it can be switched off.
When you signed up, you accepted terms and conditions that almost always include a marketing consent box. In the following weeks you will therefore receive: offers for routers, phone insurance, streaming services "included for 3 months", sometimes offers from "partners". Each of those senders must offer you a STOP option.
Three steps, in order of effectiveness:
- Untick marketing consent in your customer account with the new carrier (under "my contact preferences" or "privacy"): that is the source, and it is the only step that dries up the flow.
- Reply STOP to every short code that writes to you: the effect is real but limited to that one sender, as we explain in Replying STOP to a text: does it really work?.
- Register with Bloctel for cold calling (which does not cover texts, but deals with the other half of the problem).
If you are also changing phones when you change carriers, take the opportunity to sort through your old messages rather than migrating everything: old texts containing codes, usernames or sensitive attachments have no business on the new device. Back up anything with sentimental or legal value on a hardware-encrypted USB stick, and erase the rest before factory-resetting the old device.
Key takeaways
- A number port generates a normal volume of technical texts: they never demand a payment, an IBAN, or a code to pass on.
- There is no porting fee in France: any text claiming one is fraudulent.
- A line that goes down without you having asked for anything, together with a "SIM migration" text, should make you think of line hijacking, not maintenance.
- Messages from your former carrier after cancellation are normal for a few weeks; the commercial part can be stopped with STOP and in your contact preferences.
- The reflex when in doubt: don't click, type your customer account address by hand, forward to 33700.
Frequently asked questions
How long after the request does the line switch over?
In France, porting is completed within a maximum of three working days from the moment the receiving carrier gets the request, unless you have asked for a later date. The actual cut-off generally lasts from a few minutes to a few hours, most often in the morning.
Is the RIO code sent by text sensitive?
Yes. Combined with your number, it allows someone to request a port. Do not give it to anyone other than the carrier you are deliberately signing up with, and delete the text once the switch is complete.
Why have I stopped receiving my banking codes since the change?
During and just after the switch, authentication texts can arrive late or get lost. If this persists beyond 24 hours, the problem is usually on the network or configuration side: our guide on verification texts that don't arrive sets out the steps one by one.
Can my former carrier keep writing to me years later?
For marketing, no, if it has received your objection. Prospecting data must not be kept indefinitely: you can exercise your right to erasure with the carrier's data protection department and, if there is no reply within a month, refer the matter to the CNIL.
What should I do if I clicked and entered my banking details?
Call your bank's card-blocking line immediately, have the card blocked, then dispute any unauthorised transaction in writing. Next, file a complaint: the first 72 hours are decisive, as explained in You've been caught out by a text: the 72 hours that decide what happens next.
