Call Spoofing Protection Switzerland 2026

A call comes in. Your screen shows your bank's number, a police station or a familiar Swiss line — and the person on the line is in fact a fraudster. This is called call spoofing, and it has grown sharply in Switzerland in recent years. OFCOM records a steady increase in complaints about unwanted advertising calls and fraudulent calls.

With the revision of the Ordinance on Telecommunication Services, the Federal Council introduced two staggered obligations for all Swiss providers: since 1 July 2025, providers must check the plausibility of the outgoing CLI (Calling Line Identification); from 1 January 2026, calls from abroad that use a faked Swiss number (+41) must be blocked at the network level. This guide explains in neutral terms what spoofing is, what the new provider duties are, and how you can protect yourself in practice.

Key Takeaways

• Call spoofing is the manipulation of the displayed caller ID. Fraudsters impersonate your bank, the police, an authority or a relative to obtain data or trigger a money transfer.
• New provider duties: since 1.7.2025, Swisscom, Sunrise, Salt and all MVNOs (yallo, Wingo, M-Budget, Aldi Suisse Talk, Lebara, TalkTalk and others) must check the plausibility of outgoing CLI; from 1.1.2026, calls from abroad with a faked +41 number are blocked at the network level.
• Your first line of defence is still you: never share PIN, passwords, TAN codes or card data on the phone. Banks, the police and authorities never ask for such details on the phone.
• Reporting: to your provider (turn on the anti-spam filter), to OFCOM (online form) and, in case of financial loss, to the NCSC as well as the cantonal police.

What is call spoofing — and why does it work so well?

In call spoofing the caller manipulates the transmitted CLI so that the screen of the called person shows a different number than the one actually placing the call. This is made possible by VoIP services, which let the transmitted A-number be set almost freely — a technical weakness of the classic telephone protocol.

Spoofing works for three reasons. First, many recipients view a call as legitimate as soon as a known or local Swiss number (+41) appears. Second, fraudsters combine spoofing with social engineering: they create time pressure, pose as bank staff, police or a relative in distress, and push for immediate action. Third, familiar display names like "Police", "UBS" or "Swisscom" lower the recipient's guard.

The most common spoofing variants

The new OFCOM duties at a glance

The legal basis is the Swiss Telecommunications Act (TCA / FMG, SR 784.10) and the Ordinance on Telecommunication Services (OST / FDV, SR 784.101.1). They oblige all telecommunication service providers operating in Switzerland — Swisscom, Sunrise and Salt, MVNOs such as yallo, Wingo, M-Budget or Lebara, and pure VoIP operators — to take concrete technical measures against CLI spoofing. OFCOM supervises implementation; breaches can trigger regulatory action.

Since 1 July 2025 — outgoing plausibility check

From 1 January 2026 — blocking inbound foreign calls with Swiss CLI

These measures do not deliver perfect protection: spoofing via pure VoIP without classic telephony signalling will still occur in 2026, and fraudsters move quickly to new tactics (generic foreign numbers, faked display names in messaging-app calls). They do, however, noticeably reduce the simplest and currently most common attack pattern: faked +41 numbers from abroad.

How to protect yourself in practice

Warning signs during the call

Technical protection measures

What to do in case of a fraud attempt

Immediate actions

1. Hang up without further discussion. Politeness has no value here — fraudsters use every second to apply pressure.
2. Note the number or take a screenshot of the call log if the number was shown.
3. Do not call back. Apparently harmless foreign numbers can hide premium rates.
4. Inform your relatives, especially elderly ones. Spoofing waves are often rolled out in coordinated bursts across families or neighbourhoods.

If you have already transferred money or shared data

Key reporting points in Switzerland

Protecting the most vulnerable

Senior citizens

Older people are statistically more often targeted by phone fraud: they tend to answer more readily and to trust authority figures more. A few simple family rules cut the risk significantly:

Small and medium-sized enterprises

SMEs are targeted by CEO fraud: a fake executive or accounting department demands an urgent payment to a new account. Recommended safeguards: a four-eyes principle for payments above a defined threshold, a callback procedure to a known landline rather than direct confirmation, and regular awareness training.

FAQ

What exactly is call spoofing?

Call spoofing is the falsification of the transmitted CLI (Calling Line Identification): the screen of the called person shows a different number than the one actually placing the call. It is enabled mainly by VoIP and is used to impersonate a bank, an authority or a known contact.

What new duties apply in 2025/2026?

Since 1 July 2025, all telecom service providers operating in Switzerland must check the plausibility of outgoing CLI and filter implausible numbers. From 1 January 2026, calls from abroad with a Swiss number (+41) must be blocked or flagged at the network level, except for legitimate roaming cases. Legal basis: TCA (SR 784.10) and OST (SR 784.101.1).

Which providers are covered?

All telecom service providers licensed or registered in Switzerland: Swisscom, Sunrise and Salt, plus all MVNOs and resellers (yallo, Wingo, M-Budget, Aldi Suisse Talk, Lidl Connect, Lebara, TalkTalk, Coop Mobile, Quickline and others) as well as pure VoIP operators.

Do the new rules eliminate spoofing completely?

No. Spoofing via pure VoIP without classic signalling remains harder to detect. The rules do, however, sharply reduce the simplest pattern — faked +41 numbers from abroad. Your own caution on the phone remains essential.

Where do I report suspicious calls?

Via the online form of OFCOM (unwanted advertising and spoofing calls) and to the NCSC for suspected cyber fraud. In case of financial damage, also file a criminal complaint with the cantonal police.

What should I do if I have lost money?

Contact your bank immediately and request a recall of the transfer, block your cards, change passwords and file a police report. The faster you react, the more likely transfers within Switzerland can be stopped. Cross-border transfers, by contrast, are rarely recoverable.

Am I liable if I fall for a scam?

It depends on the case. Banks examine in particular whether you complied with your customer duties of care (keeping codes secret, handling 2FA confirmations carefully). No blanket statement is possible — seek advice from your bank, a lawyer or SKS Consumer Protection.

Conclusion

The OFCOM duties phased in during 2025/2026 — CLI checks and the blocking of faked +41 calls from abroad — are an important structural step against call spoofing in Switzerland. They reduce the most common attack pattern, but they do not replace your own caution. The best defence stays simple:

1. Be suspicious of unexpected calls, especially under pressure
2. Never share PIN, passwords, TAN codes or card data on the phone
3. In doubt, hang up and dial the official number of your bank or authority yourself
4. Inform your relatives, especially older ones
5. Report spoofing — to your provider, OFCOM and NCSC

Available in other languages

• Deutsch: Call Spoofing Schutz Schweiz 2026
• Français: Protection Call Spoofing Suisse 2026
• Italiano: Protezione Call Spoofing Svizzera 2026