Cold calling May 21, 2026 6 min read

Can we really stop the plague of phone and SMS spam?

Q: What is caller ID spoofing?

Spoofing means faking the calling number so your screen shows a local number (mobile or landline) while the actual caller is overseas. It's extremely common in training-fund scams, fake bank advisers or fake delivery drivers. Since October 2023, France's ARCEP requires operators to block obviously spoofed calls, which has cut volume without removing the problem.

Q: How do you report a spam SMS in France?

Forward the SMS to 33700 (free service), then send the sender's number in a second SMS. 33700 is run by carriers and feeds Signal Spam. For calls, you can report directly on signal-spam.fr or via Bloctel. Aggregated reports allow ARCEP and the DGCCRF to fine offenders.

Q: How can I avoid having my phone number resold?

The best strategy is compartmentalisation: use a disposable virtual number (Onoff, Hushed, or a second number from your carrier) for sign-ups to contests, loyalty programmes, delivery apps or any non-essential service. Keep your real number only for family, friends, and critical administrative services.

Q: Why do I keep getting training-fund calls even though that cold calling is banned?

Phone cold calling for CPF training has been illegal in France since April 2022 (law of 19 July 2021). Calls that still get through come almost exclusively from offshore or fraudulent actors who ignore French law. Never confirm anything by phone, never share your CPF ID, and report the calls to 33700 or signal-spam.fr.

Look, we all get those texts about a parcel that's supposedly stuck, or that random call from a number we don't know about some "training fund". It's exhausting, and it feels like no matter what we do, our number is doing the rounds everywhere. Let's break down what actually works — and, more importantly, what never really did.

TL;DR

Opposition lists like Bloctel only bite on legal French companies. Offshore scammers using caller ID spoofing couldn't care less. The strategy that works in 2026: compartmentalise (a virtual number for non-essential sign-ups), report (33700, Signal Spam), and cut the supply by removing your data from the data brokers reselling phone lists.

Section 01

Why opposition lists fail

In France, there have been initiatives like Bloctel. The idea was a good one: you sign up, and cold callers no longer have the right to call you. The thing is, it only applies to "legal" companies that play by the rules. Scammers and international spam networks using spoofing couldn't care less.

97% of French citizens say they're annoyed by phone cold calling, according to the 2024 UFC-Que Choisir survey, and nearly 60% keep getting calls despite being signed up to Bloctel.

Bloctel isn't useless — you should sign up, it's free, and it does filter out some of the classic commercial cold calling (energy, insulation, mutual insurance). But don't count on it to stop:

Training-fund scams (banned in France since April 2022, but largely offshore)
Fraudulent SMS messages (parcels, banks, tax authorities)
Automated robocalls from abroad
Charities, political surveys, debt collection (exempted)

Section 02

Spoofing: industrial number forgery

Spoofing means making a number show up on your screen that isn't actually the caller's. It's gone industrial: a call centre in the Maghreb or in Eastern Europe can generate thousands of virtual numbers — mobile, or even landline numbers from your own département — to push up the answer rate.

Since October 2023, ARCEP has required French carriers to block obviously spoofed calls (a French number calling from abroad without a legitimate interconnection). This mechanism — called MAN, for "Mécanisme d'Authentification des Numéros" — has reduced the volume without removing it. Fraudsters adapt by using "clean" numbers (legally leased) or by going through alternative carriers that don't enforce MAN.

~1 billion unwanted calls filtered every month thanks to MAN, according to ARCEP — but a significant share still slips through by exploiting weaknesses in the system.

Section 03

How your number ends up in the wild

Every time you hand over your phone number for an online contest, to create a loyalty account, or even on certain delivery apps, you're risking it leaking into poorly secured databases. And once your number is out there, it's game over: it gets resold on the dark web or directly to call centres.

The main sources of leaks, in order of impact:

Mass data breaches: a retailer gets hacked, tens of millions of numbers (along with names and emails) land on specialised forums.
Resale by data brokers: data brokers buy your contact details from every one of your commercial touchpoints and build ready-to-call lists.
Mobile apps: your number is requested to "verify your identity", then shared with third-party partners through Android/iOS permissions.
Reverse directories: your profession or your business is publicly listed, your number gets picked up by automated scraping.

Section 04

Reporting effectively (33700, Signal Spam)

Reporting won't fix your personal problem in the short term, but it feeds the statistics ARCEP, the DGCCRF and the CNIL use to fine offenders. And some of those fines are starting to hurt:

For fraudulent SMS

Forward the SMS to 33700 (free, run by carriers). You'll get an acknowledgment asking you to send the sender's number. It's natively integrated into some iOS and Android versions.

For calls

Head to signal-spam.fr or use the dedicated app. You can also file a complaint with Bloctel if the caller ignored your opposition (online form on bloctel.gouv.fr).

For confirmed scams

Report it on the THESEE platform (cybermalveillance.gouv.fr) if you've been the target of an attempted fraud. And if you've handed over banking details: file a police complaint immediately and put a stop on your card.

Section 05

Compartmentalisation: the method that works

To really fight this, you have to change tactics. Instead of trying to block numbers after the fact (they change every day), the best practice is "compartmentalisation".

1. A main number for real-life use

Family, friends, your employer, your doctor, your bank, the tax office. This number should never appear in a non-essential web form.

2. A disposable virtual number for everything else

Apps like Onoff, Hushed, Symlex, or simply a second number with your carrier (often €3-5/month). This number is for sign-ups, contests, loyalty programmes, deliveries. If it gets spammed, you bin it and create another — without ever touching your main identity.

3. Cutting it at the source

Even with a locked-down main number, it may already be sitting in some data broker's files from older breaches. Services like Sheeldy contact those brokers under GDPR rules to have your number deleted from their databases — which gradually shrinks cold calling at the root.

Frequently asked questions

Does Bloctel really work against phone cold calling?

Only partially. Bloctel forces legal French companies not to call numbers on the list, under threat of a fine. In practice the service cuts some calls but doesn't stop offshore cold callers, scammers using spoofing or fraudulent SMS. Sign up anyway on bloctel.gouv.fr — it's free — but without any illusions.

What is caller ID spoofing?

Spoofing means faking the calling number so your screen shows a local number while the actual caller is overseas. Very common in training-fund scams, fake bank advisers or fake delivery drivers. Since October 2023, France's ARCEP has required carriers to block obviously spoofed calls.

How do you report a spam SMS in France?

Forward the SMS to 33700 (free service), then send the sender's number in a second SMS. 33700 is run by carriers and feeds Signal Spam. For calls, you can report directly on signal-spam.fr or via Bloctel.

How can I avoid having my phone number resold?

The best strategy is compartmentalisation: use a disposable virtual number (Onoff, Hushed, or a second carrier line) for sign-ups to contests, loyalty programmes, delivery apps or any non-essential service. Keep your real number only for family, friends, and critical administrative services.

Why do I keep getting training-fund calls even though that cold calling is banned?

Phone cold calling for CPF training has been banned in France since April 2022. The calls that still get through come almost exclusively from offshore or fraudulent actors. Never confirm anything by phone, never share your CPF ID, and report the calls to 33700 or signal-spam.fr.

Factual sources Statistics from the Signal Spam platform · Annual reports from ARCEP on premium-rate numbers, cold calling and the MAN mechanism · French law no. 2020-901 of 24 July 2020 regulating phone cold calling and fighting fraudulent calls · Law of 19 July 2021 banning CPF cold calling (applicable since April 2022).

In a nutshell

Stopping phone spam in 2026 isn't a fight you win with a single move. You have to combine: sign up to Bloctel (free, useful against legal cold callers), report everything to 33700, compartmentalise with a virtual number for non-critical services, and most importantly, remove your number from the data brokers fuelling the whole chain. It's the only strategy that holds up over time.