Your phone rings. It’s an unknown number. You stare at the screen, let it ring out and wait to see if a WhatsApp message follows. Sound familiar? You’re not alone – and you’re part of a growing problem for South Africa’s mobile operators.
The reflex to reject or ignore unfamiliar callers has become so deeply ingrained that it’s now reshaping how tens of millions of South Africans use their phones. And while the root cause – an epidemic of spam and scam calls – is well documented, the knock-on effects on operator revenue are only now coming into sharper focus.
At an event hosted by Truecaller in Johannesburg last week, Mmathebe Zvobwo, the company’s director for market development in South Africa, said the overwhelming volume of spam and scam interactions has led to dismissive attitudes among South Africans, with many opting not to answer calls from unknown numbers at all, choosing rather to wait for a follow-up e-mail or text if it’s important.
“Taking the right call is critical because, by default, people don’t answer their phones. So, if a call comes in, unless it’s your spouse, child, friend or mother, people are not eager to answer their phone. But on the flip side, that could be a recruiter or talent manager trying to reach you,” said Zvobwo.
South Africans are inundated with spam calls and the rate at which they are being bombarded is on the rise. Truecaller data shows that over 30 billion spam calls were received by South Africans in 2025. The first three months of 2026 have shown a 20% year-on-year rise in spam and scam calls.
The problem is just as severe globally, with Truecaller’s announcement this week that it has breached the 500 million user milestone testament to the scale of the issue.
Gouger of revenues
If people are responding to this by refusing to take calls, mobile operators are losing out on potential income. South Africa’s mobile operators that were queried by TechCentral agree. However, the impact is not as severe as one might expect, mostly because traditional voice revenues have been in decline for many years already.
The biggest gouger of voice revenues has been lower-cost, data-driven voice and video calling, first enabled by applications like the now-defunct Skype. Nowadays, WhatsApp calling dominates the consumer space, while apps such as Teams and Zoom cater for the business market.
Read: Truecaller cooperating with Info Regulator’s Popia probe
“The increase in spam and scam calls has changed how consumers engage with voice calls across the industry, with many people more cautious about answering unknown numbers. While this does affect call behaviour, voice usage trends are shaped by multiple factors, including the broader shift to data-based and OTT (over the top) communication, and it would not be appropriate to isolate or quantify the impact of spam calls on operator revenue in simple terms,” said Bryan O’Donovan, chief data and analytics officer at Cell C.
Operators have a responsibility to limit the amount of spam and scam calls carried over their networks. According to O’Donovan, Cell C “applies a layered, industry-aligned approach” to reduce spam traffic on its network. “Suspicious calling patterns are measured on a case-by-case basis,” he said.
MTN South Africa has observed similar patterns regarding the transition to data services and the impact of spam calls on user behaviour.
“There has been a noticeable change in how customers engage with voice calls, including a reluctance to answer calls from unknown numbers. This shift can be attributed to a range of factors, including availability, changing communication habits and industry-wide concerns around spam calls. Although spam is not the primary driver of declining voice traffic and revenues, the main factor remains the migration towards data-based messaging platforms,” said MTN South Africa.
Read: Spam calls surge in South Africa despite apps, laws and tech fixes
MTN said it works closely with regulators and industry bodies to “create a safer communications environment for all South Africans”. Over and above its efforts to block spam traffic on the network side, it encourages its users to remain cautious when sharing personal information, like their contact number, online or through surveys. Cell C’s O’Donovan shared a similar sentiment, adding that customer awareness remains an important part of solving the spam call issue.
AI call screening is one of the most effective methods for controlling spam available today. Truecaller recently incorporated the feature into its paid subscription tier. It includes an AI-powered voice assistant that asks the caller to state their name and reason for calling. The response is transcribed on the receiver’s screen in real time, giving them the option to either answer or ignore the call.
Apple has a native AI call screening feature that was released with the iOS 26 update last September. For users with multiple devices in the Apple ecosystem, the live transcription of the incoming call is made visible on their iPad, MacBook and iMac, too, provided these devices are connected to the internet at the time. – © 2026 NewsCentral Media
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