Short answer: replying STOP to a marketing text works when the sender is an identifiable company using a French short code (36xxx, 38xxx, 2xxxx) or an alphanumeric sender ID. The reply is free or charged as a standard text message, never premium-rated, and the advertiser is legally obliged to remove you from its database. On the other hand, when you're facing a scam text or an unknown 06/07 number, replying STOP achieves nothing: you need to forward the message to 33700 and block the sender.
Updated 23 October 2026.
It's the line everyone reads without reading: "STOP au 36173", "STOP SMS au 38042", "To stop receiving our offers: STOP". It appears at the end of almost every commercial text message received in France, because it is legally required. And yet two questions come up every single time: will this cost me anything? and does it actually work?
The answers are "no" and "yes, but not always" — and the nuance has very concrete consequences, because the same word sent to the wrong recipient can do exactly the opposite of what you want.
Why does the STOP line appear on every marketing text?
Because French law requires a simple, free way to opt out of SMS marketing.
Two sets of rules overlap:
- the French Post and Electronic Communications Code (article L. 34-5), which governs direct marketing by automated message and requires a simple, cost-free means of refusal;
- the GDPR, which guarantees the right to object to the processing of your data for marketing purposes, as restated by the CNIL in its guidance on commercial prospecting by SMS.
The industry turned this obligation into a single technical standard: STOP SMS, managed by the AF2M (Association française du multimédia mobile), which coordinates short codes with the mobile operators. In practice, every marketing text sent from a French short code must state the keyword and the number to send it to.
That's why the line looks so mechanical: it isn't a commercial courtesy, it's a regulatory checkbox.
Does replying STOP cost money or come at a premium rate?
No. The opt-out text is free or counted as a standard text message from your plan, never premium-rated.
This is the point that stops most people: you see a five-digit number, you vaguely remember something about 50-cent text messages, and you don't dare reply. The rule, though, is stable:
| Situation | Cost of your STOP reply | Expected effect |
|---|---|---|
| Marketing text from a brand, short code 36xxx/38xxx | Free or the price of a text from your plan | Removal from the advertiser's database |
| Subscription service you signed up for (content, paid alerts) | Free | Cancellation of the subscription and end of billing |
| Alphanumeric sender ID ("PROMOXX", "BOUTIQUE") | Often impossible to reply | Use the link or keyword given in the message |
| Scam text (fake parcel, fake tax notice, fake adviser) | Price of a text, but pointless | No effect, and your number is confirmed as active |
The subscription case deserves one clarification: if you're paying for an SMS service you never intended to buy, STOP stops the charges going forward; it doesn't refund what has already been billed. To dispute amounts already taken, you need to go through your mobile operator and then, if necessary, the publisher's customer service — and keep a screenshot of the original message. How these traps work is covered in detail in our article on gift texts that trigger a subscription.
How do you reply STOP properly?
By sending the exact keyword given in the message, to the exact number given in the message.
- Open the text you received and read the last line: it contains the keyword and the number ("STOP au 36173", "STOPPUB au 38042").
- Reply directly in the conversation thread, or start a new message to that short code.
- Write only the keyword, with no punctuation, no sentence, no explanation: "STOP" and nothing else. The platforms read a keyword, not a polite request.
- If the message specifies a particular keyword (STOPPUB, STOP SMS, STOP 2), use that one: a different keyword may not be recognised.
- Wait for the confirmation text. Most platforms send back an acknowledgement along the lines of "Your request has been registered".
- Keep a screenshot of the original message and of your reply. That's your evidence if the marketing continues.
One detail that often trips people up: some senders don't show up as a number but as a name (an alphanumeric sender ID). Technically, you can't reply to that kind of message. In that case, the text must contain another way out — an unsubscribe link, a keyword to send to a short code, a customer service number. If there's none at all, the message is already non-compliant: that's a case for reporting, not for opting out. To work out who you're dealing with, our guide to decoding a short code or an alphanumeric sender ID sets out the method.
How long before the texts stop?
Expect anything from a few minutes to a few days. One stray message may still arrive if a campaign was already queued up when you replied.
In practice, the opt-out is recorded almost immediately on the platform side, but marketing campaigns are often prepared in advance, with the recipient list locked several hours or several days before sending. A text that arrives the day after your STOP isn't necessarily a sign your request was ignored.
If the messages keep coming beyond a week or two, however, something is wrong. You're then facing one of these three situations:
- the database has been sold or shared, and the next sender is a different company, with its own STOP to send;
- the advertiser is ignoring your objection, which is an offence: the CNIL accepts online complaints at cnil.fr;
- it wasn't advertising at all but disguised smishing, and replying never stood a chance of working.
This is also a good moment to tidy things up at the source. A lot of marketing starts with a form you filled in once, a loyalty card or a prize draw. Writing down the sites where you've left your number in a password notebook helps you trace the source when the messages pile up — and ask for deletion in the right place instead of replying STOP indefinitely. We break down this mechanism in our article on texts received after an in-store purchase.
When should you absolutely NOT reply STOP?
When the message isn't advertising but an attempted scam. In that case, replying backfires.
A fraudulent text isn't sent by an advertiser subject to regulation: it comes from a short-lived campaign, often from a foreign mobile number or a burner SIM, sometimes from a spoofed sender ID. Nobody processes the word STOP there. Worse, it hands the scammer a valuable piece of information: this number is active and its owner reads their messages. In other words, you move from a randomly generated list to a list of qualified targets.
The warning signs that should make you skip the STOP:
- the message announces an urgent problem (parcel on hold, fine, suspended account, file to put in order);
- it contains a link to a domain that isn't the one belonging to the organisation it names;
- it demands a small payment (customs charges, processing fees of €1.99, €2.99);
- it asks for a verification code, a login or bank details;
- the sender is an 06/07 or a foreign number while claiming to speak on behalf of a government body or a bank.
In all these cases, the right reflex is different: forward the message to 33700 (free, the official scheme against unwanted text messages), then block the sender. The page Unwanted texts and 33700 sets out the procedure, and our article on what happens to your report to 33700 explains what happens next on the operators' side.
What if I've already replied STOP to a scam?
It's not a disaster. You haven't handed over any personal data, any login or any payment method. Simply expect more approaches over the following weeks, and filter them out without replying. If, on the other hand, you clicked a link or entered information, the situation changes completely: the right steps are described in our article on the 72 hours after falling for a text scam.
What to do when STOP isn't enough?
Stack the tools, because none of them covers the whole range of unwanted messages on its own.
STOP SMS, Bloctel and blocking on your phone deal with three different areas, and that's the most common source of confusion:
| Tool | What it handles | What it doesn't handle |
|---|---|---|
| STOP SMS (keyword to the short code) | SMS marketing from an identified advertiser | Calls, scams, other advertisers |
| 33700 (forwarding the message) | Unwanted or fraudulent texts and calls, on the operators' side | Your individual removal from a marketing database |
| Bloctel | Telephone cold calling (calls) | Marketing text messages |
| Blocking the number on your phone | One specific sender, immediately | Campaigns that change number with every send |
| Messaging app spam filter | Messages from unknown senders, set aside | Senders already in your contacts |
The built-in filter is worth switching on, because it works around the clock: on iPhone, Settings → Apps → Messages → Filter Unknown Senders; on Android with Google Messages, Settings → Spam protection. Suspicious messages then land in a separate tab, with no notification. We've covered all the useful settings in our guide to iOS and Android messaging settings.
For numbers that keep coming back, keeping a written list rather than digging through your history saves time: a simple pocket notepad next to the phone is enough to note the date, the number and the type of message — handy if you end up filing a CNIL complaint, which calls for precise details.
And if you're helping someone less confident with technology, the real issue isn't technical but one of trust: the how-to is in our guide to protecting an elderly parent from scam texts. A desk phone stand and a more legible display make more difference than any lecture: you reread a message calmly instead of clicking in a panic.
The most common mistakes
- Writing a sentence instead of the keyword. "Hello, please stop sending me messages" won't be processed by an automated system. Send the word on its own.
- Replying to the wrong number. The keyword works with the short code given in that message, not with another brand's.
- Assuming one STOP covers everything. Each advertiser manages its own database: there is no universal opt-out from marketing texts in France.
- Mixing up Bloctel and STOP SMS. Bloctel doesn't cover text messages, only cold calls.
- Deleting the message before reporting it. If you want to forward it to 33700 or prove an abusive send, keep it, or at the very least a screenshot of it. For a case that may drag on, a pocket portable printer or a simple dated backup is enough to keep usable evidence.
Key takeaways
Replying STOP is free, lawful and effective — but only within the scope this mechanism was created for: commercial marketing from identifiable companies going through a French short code. Outside that scope, STOP isn't protection, it's a signal.
The sorting rule fits in one sentence: if the message is trying to sell me something, I reply STOP; if it's trying to scare me or make me click, I forward it to 33700.
Frequently asked questions
Does replying STOP to a text cost money?
No. The reply is free or counted as a standard text message from your plan. An opt-out text cannot be premium-rated: that's a regulatory requirement for all SMS marketing in France.
Should you reply STOP to a scam text?
No. Nobody processes those replies, and replying tells the scammer your number is active and read. Forward the message to 33700, then block the sender and delete the message once you've reported it.
The texts keep coming after my STOP — what now?
First check that it really is the same sender: each advertiser has its own database. If it is, and the messages persist beyond two weeks, keep the screenshots and file a complaint with the CNIL.
Does Bloctel block marketing texts?
No. Bloctel is the opt-out scheme for telephone cold calling: it covers calls, not messages. For texts, the tools are STOP, 33700 and the filters in your messaging app.
Can you reply STOP to a sender shown as a name?
Generally no: an alphanumeric sender ID can't receive replies. The message must then offer another way to opt out (unsubscribe link, keyword to a short code). If it contains none, the send is non-compliant and can be reported.
