Starting July 1, telecommunications providers in Switzerland are required to label all incoming international calls that mimic Swiss mobile numbers. This new mandate expands upon existing regulations that already required the labeling of spoofed Swiss landline numbers, aiming to curb a rising tide of fraudulent activity where criminals pose as banks, police, or other authorities to deceive consumers.
According to the Federal Office for Cybersecurity (Bacs), hundreds of fraud cases are reported weekly, many of which originate from spoofing—a technique where perpetrators hide their actual location to make a call appear as if it is coming from a trusted, local source. By flagging these calls as “unknown” or “anonymous” on recipient displays, providers intend to give consumers the necessary information to decide whether or not to answer.
How the new labeling mandate works
The expansion of the labeling requirement to include mobile prefixes, such as 079, follows a similar policy implemented for fixed-line numbers earlier this year. Major providers including Salt, Sunrise, and Swisscom have confirmed their commitment to the new guidelines. The process relies on inter-provider cooperation, where companies share information regarding suspicious traffic. For instance, if a call appearing to originate from a Swisscom number is directed toward a Sunrise customer, the system is designed to identify the spoofing attempt and label the call as “anonymous” for the recipient.
Did You Know? The Federal Office for Cybersecurity (Bacs) receives hundreds of reports of fraud every week, with a significant portion of these criminal attempts beginning as spoofing calls.
What are the expected impacts?
While the industry expects the measures to improve the fight against telephone fraud, providers have stopped short of quantifying the success of these interventions. Sunrise stated that it is currently too early to provide reliable data on the impact of the rules, while Salt noted that quantifying the specific effects remains difficult. Swisscom, however, reported an increase in blocked and anonymized calls compared to the previous year. The company expects the new measures to be a strong tool in combating spoofing, though it acknowledged that the situation remains a persistent “cat-and-mouse game.”
Expert Insight: The transition from manual vigilance to automated labeling represents a shift in how infrastructure providers address security. While labeling provides a critical layer of defense, the inherent nature of spoofing—which relies on technical manipulation of caller ID data—suggests that users will likely need to maintain a high level of skepticism toward unsolicited calls even after these safeguards are fully integrated.
Frequently Asked Questions
What happens if I receive a call that has been labeled as anonymous?
The labeling is intended to alert you that the call is likely an international spoofing attempt. You can then decide for yourself whether to accept or decline the call.
Are all Swiss mobile numbers affected by this new rule?
No. The rule specifically applies to international calls that are spoofing or “faking” a Swiss mobile number. Legitimate calls from within Switzerland are not subject to this labeling requirement.
Have the telecommunications providers released data on how many calls are blocked?
No. While Swisscom confirmed they are seeing “significantly more” blocked and anonymized calls than in the previous year, they and other providers have not yet released specific, concrete statistics on the overall impact of the new measures.
How will you change your phone habits when you see an “anonymous” label on your screen?
