South Africa’s Spam Call Epidemic Is Quietly Draining Mobile Operator Revenue
Your phone buzzes with an unknown number. You stare at it, let it ring out, and wait to see if a WhatsApp message follows. If that sounds like your daily routine, you are far from alone — and this behaviour is becoming a serious headache for South Africa’s mobile operators.
The habit of rejecting or ignoring calls from unfamiliar numbers has become second nature for millions of South Africans. While the root of the problem — a relentless flood of spam and scam calls — is well known, the financial ripple effect on telecoms operators is only now being fully understood.
At a recent Truecaller event held in Johannesburg, Mmathebe Zvobwo, the company’s director for market development in South Africa, highlighted just how deeply this culture of call avoidance has taken hold. She noted that the sheer volume of spam interactions has made South Africans dismissive of their own phones, with many choosing to simply wait for a follow-up email or text before engaging with any unknown caller.
“Taking the right call is critical because, by default, people don’t answer their phones,” Zvobwo said. “If a call comes in, unless it’s your spouse, child, friend or mother, people are not eager to answer. But that could be a recruiter or talent manager trying to reach you.”
The scale of the problem is staggering. According to Truecaller data, South Africans received over 30 billion spam calls in 2025 alone. What’s more alarming is that the first quarter of 2026 has already shown a 20% year-on-year increase in spam and scam call volumes. Globally, the issue is equally severe — Truecaller’s recent announcement that it has crossed the 500 million user milestone underscores just how widespread the crisis has become.
How Spam Calls Are Gouging Mobile Operator Revenues
With consumers increasingly refusing to pick up their phones, mobile operators are feeling the pinch. Several of South Africa’s major operators confirmed to industry media that call avoidance is indeed affecting user behaviour — though the financial damage is being cushioned by a longer-running trend.
The biggest blow to traditional voice revenues has actually come from data-driven communication platforms. Apps like WhatsApp dominate consumer calling, while platforms such as Microsoft Teams and Zoom have largely replaced conventional calls in the business world. The era of paying per-minute voice charges is already fading fast.
Bryan O’Donovan, chief data and analytics officer at Cell C, acknowledged that spam and scam calls have changed how consumers engage with voice communications across the board. He noted, however, that it would be overly simplistic to pin all revenue decline solely on spam. “Voice usage trends are shaped by multiple factors, including the broader shift to data-based and OTT communication,” he said.
Cell C says it applies a “layered, industry-aligned approach” to reduce spam traffic on its network, with suspicious calling patterns monitored on a case-by-case basis. MTN South Africa echoed these concerns, observing a clear reluctance among customers to answer calls from unknown numbers. The operator attributed the trend to a combination of changing communication habits, platform availability, and industry-wide spam concerns.
MTN stated that it works closely with regulators and industry bodies to build “a safer communications environment for all South Africans.” Beyond network-level spam blocking, MTN is also urging users to be more careful about sharing personal contact information online or through surveys. O’Donovan at Cell C echoed this view, emphasising that customer awareness remains a critical piece of the puzzle.
On the technology front, AI-powered call screening is emerging as one of the most effective defences available to consumers today. Truecaller recently rolled out an AI call screening feature as part of its paid subscription tier. The tool uses a voice assistant to ask callers to identify themselves and state their reason for calling, with the response transcribed in real time on the recipient’s screen — allowing them to decide whether to answer or reject the call.
Apple has also entered the space, releasing a native AI call screening feature with its iOS 26 update last September. For users within the broader Apple ecosystem, the live transcription is even displayed across connected devices, including iPads, MacBooks and iMacs, as long as they are online at the time of the call.
The convergence of regulatory pressure, technological innovation, and growing public awareness may eventually help stem the tide of spam calls flooding South African networks. But for now, the ring, reject, repeat cycle shows no sign of slowing down — and both consumers and operators are paying the price.