Spam calls are killing voice calling in South Africa

South African mobile network operators Vodacom and MTN have experienced reduced call revenues amid surging spam call rates in the country.

TrueCaller recently revealed that spam call rates were 25% higher in the first half of 2026 than in the first half of 2025.

According to TrueCaller’s data, South Africans were targeted by nearly 17.5 billion spam calls in the first six months of the year.

Mmathebe Zvobwo, TrueCaller’s director for market development in South Africa, told BusinessDayTV that sales spam is dominant in South Africa.

“In July alone, a lot of those spam and scam calls were sales, with a 64% contribution to the overall number. They’re primarily sales calls. They’re primarily telemarketers,” she said.

She added that the next-highest contributor was calls related to financial and utility services. Zvobwo said South Africa was a prime target for spam and scam calls.

“South Africa is a very interesting country because we’ve got over 196% mobile penetration, so that means on average, South Africans have two phones or two SIM cards,” she said.

“We are a mobile-first country. We’ve got about 79% Internet penetration. It obviously creates the perfect ecosystem from a spam, scam, and fraudulent activity perspective.”

The rising trend in spam targeting South Africans has affected MTN and Vodacom’s call revenues in recent years.

MTN South Africa told MyBroadband that it had observed a gradual decline in voice revenue in recent years.

“There has been a noticeable change in how customers engage with voice calls, including a reluctance to answer calls from unknown numbers,” MTN South Africa said.

It said the declines in voice call revenue were attributed to factors such as availability, shifting communication habits, and industry-wide concerns about spam calls.

“The disruptive nature of spam calls can discourage users from engaging with legitimate calls, indirectly impacting usage,” MTN South Africa said.

WhatsApp calls hurt revenues more

MTN encourages customers to use call identification tools like TrueCaller and to be cautious when sharing personal information online or through services.

“The company also continues to work closely with regulators and industry bodies to help create a safer, more trusted communications environment for all South Africans,” MTN said.

Vodacom spokesperson Byron Kennedy said spam calls were an industry-wide challenge that contributed to shifts in customer behaviour.

Vodacom and MTN both said that the impact of over-the-top (OTT) data-based services, such as WhatsApp calls, on revenue was more severe.

MTN South Africa said the primary driver behind declining voice call revenues was customers shifting to data-based platforms.

“The increasing adoption of mobile data and platforms such as WhatsApp and Microsoft Teams has significantly influenced this trend,” MTN South Africa said.

Vodacom’s Kennedy said outbound voice minutes declined by 6.4% in South Africa in its last financial quarter, confirming a managed migration to OTT services.

“We expect customer communication patterns to continue to evolve with smartphone adoption, with voice remaining an important and resilient service for Vodacom,” he said.

MyBroadband analysed Vodacom’s voice call revenues and subscribers’ average monthly usage from its 2021 to 2026 fiscal years.

Total voice traffic declined by 12.63% over the six years, from 68,455 million minutes in 2021 to 59,810 million minutes in 2026.

The primary driver was a decline in outgoing minutes, which fell by 17.74% from 57,586 million to 47,371 million over the same period.

Incoming voice traffic increased by 14.44% over the period, from 10,869 million minutes to 12,439 million minutes.

Average monthly usage per subscriber dropped from 136 minutes in 2021 to 108 minutes in 2026, with postpaid users’ usage declining the most.

Their average monthly usage declined from 195 minutes to 121 minutes over the period, while prepaid usage declined from 126 minutes to 105 minutes.