Call Spoofing Protection Switzerland 2026

A call comes in. Your screen shows your bank's number, a police station or a familiar Swiss line — yet the person on the line is a fraudster. This is call spoofing, and complaints about it have risen sharply in Switzerland. To curb it, the Federal Office of Communications (OFCOM/BAKOM) has agreed new obligations with Swiss providers, phased in across 2026.

So what actually changes, and when? From 1 January 2026, calls arriving from abroad that display a faked Swiss landline number must be marked as "unknown" or blocked at the network level. From 1 July 2026, the same protection extends to faked Swiss mobile numbers. This guide explains in neutral terms what spoofing is, what the new provider duties really require, and how you can protect yourself in practice.

Key Takeaways

• Call spoofing is the manipulation of the displayed caller ID (CLI). Fraudsters impersonate your bank, the police, an authority or a relative to obtain data or trigger a money transfer.
• New provider duties, phased: from 1 January 2026, foreign calls that fake a Swiss landline number must be flagged as "unknown" or blocked; from 1 July 2026 this also covers faked Swiss mobile numbers. The legal basis is Art. 26a para. 6 of the Ordinance on Telecommunication Services (FDV/OST, SR 784.101.1).
• How it works technically: transit providers must mark incoming foreign calls that show a Swiss number; where marking is not possible, they must remove the number. The provider that delivers the call to you can then suppress the number or block the call.
• Your first line of defence is still you: never share a PIN, passwords, TAN codes or card data on the phone. Banks, the police and authorities never ask for these on the phone.
• Reporting: to your provider (turn on the anti-spam filter), to OFCOM/BAKOM (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 (Calling Line Identification) so that your screen shows a different number than the one actually placing the call. This is made possible mainly by VoIP services, which let the transmitted A-number be set almost freely — a structural weakness of the classic telephone protocol.

Spoofing works for three reasons. First, many recipients treat a call as legitimate the moment a known or local Swiss number (+41) appears. Second, fraudsters pair 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 such as "Police", "UBS" or "Swisscom" lower the recipient's guard.

Jargon, briefly

• CLI (Calling Line Identification): the caller number transmitted with a call and shown on your display.
• Spoofing: deliberately faking that number so it shows something other than the real origin.
• Transit provider: a network operator that carries a call between two other networks — here, the link between the foreign origin and your Swiss provider.

The most common spoofing variants

The new OFCOM duties at a glance

The legal basis is the Swiss Telecommunications Act (FMG / TCA, SR 784.10) and the Ordinance on Telecommunication Services (FDV / OST, SR 784.101.1), in particular Art. 26a. They oblige telecommunication service providers operating in Switzerland — Swisscom, Sunrise and Salt, MVNOs such as yallo, Wingo, M-Budget, Coop Mobile or Lebara, and pure VoIP operators — to take concrete technical measures against CLI spoofing from abroad. OFCOM supervises implementation; breaches can trigger regulatory action.

The mechanism runs along the call path. Under Art. 26a para. 6 FDV, transit providers must add an indicator that marks incoming foreign calls displaying a Swiss number — including the identity of the marking transit provider. Where that marking is technically impossible, the transit provider must remove the caller number. The terminating provider, which actually delivers the call to your phone, can then recognise the manipulation more easily and either show the call as "unknown" or block it entirely.

From 1 January 2026 — Swiss landline numbers

From 1 July 2026 — Swiss mobile numbers

Alongside these spoofing rules, an older duty still applies: under Art. 82 ff. FDV, providers must offer a filter against unwanted advertising calls. Swisscom, Sunrise, Salt and several MVNOs now run such network-side filters; Swisscom reports blocking roughly one million suspicious calls a month. OFCOM developed the new anti-spoofing measures together with the industry and coordinated with authorities in Austria and Germany, where comparable rules sharply reduced reported cases.

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, cut the simplest and currently most common pattern: faked +41 numbers from abroad.

How to protect yourself in practice

If you are reviewing your setup anyway, it is worth checking which spam protection your plan includes — our mobile plans Switzerland overview and the mobile internet guide show what each provider offers.

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:

For households with several lines, a family mobile plan can make it easier to manage spam filters and contracts in one place.

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): your screen 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 2026?

From 1 January 2026, providers must mark or block foreign calls that display a faked Swiss landline number. From 1 July 2026, the same protection extends to faked Swiss mobile numbers. The mechanism is set out in Art. 26a para. 6 FDV (SR 784.101.1) under the Telecommunications Act (FMG, SR 784.10): transit providers mark or remove the number, and the delivering provider can then suppress or block the call.

Why are landline and mobile numbers protected on different dates?

The rules are phased for technical reasons. The marking and verification mechanism was rolled out first for fixed-line numbers (from 1 January 2026) and then extended to mobile numbers (from 1 July 2026), giving providers and transit operators time to implement the signalling across both network types.

Which providers are covered?

All telecom service providers 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 transit and pure VoIP operators.

Do the new rules eliminate spoofing completely?

No. Spoofing via pure VoIP without classic signalling remains harder to detect, and fraudsters switch to generic foreign numbers or faked names in messaging-app calls. The rules do 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/BAKOM (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 across 2026 — marking and blocking faked +41 calls from abroad, first for landline numbers (1 January 2026), then for mobile numbers (1 July 2026) — are a 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 a 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/BAKOM and the NCSC

If a blackout is also on your mind, see our guide on mobile networks during a power outage.

Available in other languages

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