Data privacy and unlawful interception of information laws prevent South Africa’s mobile operators from getting tougher in the first against spam calls at the network layer – but interventions taken in international markets including Australia suggests more can still be done.

TechCentral reported last week that South Africa’s spam call epidemic is getting worse, despite multipronged efforts to fight the scourge. Interventions by regulators, third-party application developers and even device manufacturers continue to be circumvented by unscrupulous telemarketers and scammers, leaving users wondering what can be done.

It’s at the network layer that operators have room to implement technical solutions to block spam calls before they are routed to customers. However, there are a number of technical challenges that make such interventions impractical, with adherence to data privacy laws also a big concern for operators.

“It is important to note that we as Vodacom do not monitor communication content over our network, and therefore we cannot distinguish if such content is spam or not as this would amount to unlawful interception of communication in terms of Rica (the Regulation of Interception of Communications and Provision of Communication-Related Information Act),” a Vodacom spokesman told TechCentral via e-mail. “We are however willing to work with the authorities in support of lawful measures to be taken to manage spam.”

The fact that mobile operators do not monitor their customers’ calls does not mean they do not take any action to fight the problem. An MTN South Africa spokesman told TechCentral that measures are taken at the interconnect and wholesale level, which include network security and spam filtering tools “that use international best-practice learnings, processes and live global information”.

Mobile operators maintain their own databases of spam and scam call sources, using automated network monitoring tools to keep them out. However, spammers change the numbers they use frequently, using international phone numbers and spoofing – where they pose as legitimate and trusted entities – to circumvent network security protocols.

Monitoring and enforcement

According to MTN, the regulatory framework – encompassing Protection of Personal Information Act (Popia) and the Consumer Protection Act (CPA) – already prohibits direct marketing to consumers without prior consent. However, these laws are not enforced properly.

“The main challenge lies in monitoring and enforcement. Strengthening regulatory capacity to investigate complaints and take action against repeat offenders is crucial,” said MTN.

Vodacom noted that customers have the option to opt out from direct marketing calls and can sign up with the Direct Marketing Association’s Do Not Contact list. Furthermore, unsolicited SMSes can be reported to the Wireless Service Providers’ Association.

Read: Scam call epidemic: lessons for South Africa from Down Under

MTN said it also encourages consumers to report spam calls to relevant regulators, adding that customers ought to use in-device call-blocking features or reputable third-party apps to filter unwanted calls.

Lessons from other markets like Australia suggest there is room for South Africa’s telecoms sector – including regulators and operators – to work more closely together to fight the plague of scam and spam calls.

In 2022, the Australian Communications and Media Authority introduced legislation that placed mandatory obligations on mobile operators to identify, trace and block scam calls and SMSes. To meet these obligations, operators had to implement systems to detect and block suspicious calls at the network level before they could reach users. The regulator said operators reported blocking more than 2.3 billion scam calls and “hundreds of millions” of scam SMSes by December 2024.

“We work to reduce the threat of phone scams by making, promoting and enforcing telco rules, collaborating domestically and internationally, and progressing initiatives such as the SMS sender ID register to make Australia a hard target for scammers,” the regulator said.

The regulations also require Australian operators to share information that will help identify and disrupt scam campaigns with each other and other government bodies. Systems to prevent the spoofing of numbers, where scammers pose as legitimate businesses, were also legislated.

In another initiative, the Australian regulator in December 2023 piloted an SMS sender ID register, which is essentially a database held by mobile operators used to confirm that messages claiming to be from an official institution such as the government or a bank are really from that source.

Even if regulatory changes were made to give mobile operators the leeway to monitor the traffic carried over their networks in more detail, they would still be restricted by certain practical considerations.

“A key challenge in stopping spam calls lies in the inability of mobile networks to accurately assess the nature or intent of a voice call in real time. Unlike SMS or e-mail, where content can be scanned, voice communication does not offer the same visibility,” said MTN. – © 2025 NewsCentral Media

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