Key Takeaways:
Fixed line subscriptions dropped by 7.94%, continuing a steady long-term decline.
Fixed network voice traffic rose by 8.12%, showing residual reliance in key sectors.
VoIP adoption is surging among SMEs due to cost savings, flexibility, and remote capabilities.
Mobile voice and data dominate user communication preferences, with over 116 million subscriptions.
Broadband growth (up 3.43%) strengthens VoIP infrastructure and accelerates mobile substitution.
South Africa’s telecommunications landscape is undergoing a significant transformation, with fixed line usage declining, mobile and VoIP (Voice over Internet Protocol) services gaining ground, and user behaviour evolving rapidly in response to digital alternatives.
Drawing from ICASA’s State of the ICT Sector Report (2025), we unpack the key trends shaping the voice communication market — from fixed line revenues to VoIP calling trends and mobile substitution.
Fixed Line Services: Still Declining, But Not Dead Yet
The slow fade of fixed line services continues. According to the 2025 ICASA report, fixed line voice subscriptions dropped to 1.35 million, down from 1.47 million in the previous year — marking a 7.94% year-on-year decline.
This isn’t new. Over the past decade, South Africa has seen a consistent drop in landline usage. Telkom, once the dominant fixed-line provider, has shifted its focus toward mobile and LTE offerings. But despite the slide, fixed lines haven’t disappeared entirely. Certain enterprise sectors — including finance, legal, and call centres — still use fixed lines for redundancy, regulatory, or operational reasons.
The VoIP Rise: Flexible, Affordable and Scalable
While fixed lines fade, VoIP services are thriving, especially among small to medium enterprises (SMEs). VoIP solutions — such as cloud PBX systems — have become the go-to for businesses seeking cost efficiency, scalability, and geographic flexibility. Unlike traditional landlines, VoIP calls are routed over broadband internet, which removes the need for copper lines and physical infrastructure.
While ICASA’s report doesn’t explicitly break out VoIP revenue, it notes a 3.43% increase in fixed line broadband subscriptions, indicating that the infrastructure needed for VoIP is expanding.
Coupled with the availability of Fibre to the Business (FTTB) and high-speed LTE services, the foundation for cloud-based telephony continues to strengthen.
Companies are no longer confined by geography or hardware. With virtual numbers and web-based calling apps, VoIP is enabling distributed teams, remote workforces, and more agile customer service models. And in a country grappling with load shedding and rising costs, the lower overheads of VoIP vs. traditional PABX systems are increasingly attractive.
Mobile vs Fixed Calling: The Substitution Effect
The substitution of mobile for fixed line calling is a global trend, but it’s especially pronounced in South Africa. ICASA’s report shows that mobile cellular voice subscriptions (prepaid and postpaid) continue to dominate, with a total of 116 million active subscriptions recorded — more than double the population due to multi-SIM usage.
Mobile is clearly king, but it’s also evolving. With the increase in LTE and 5G devices (up by 13.97% year-on-year), mobile voice services are increasingly carried over data networks, making the line between mobile voice and VoIP even blurrier.
In this context, traditional voice minutes — whether from fixed or mobile — are becoming less relevant than overall connectivity and data capacity. Businesses now assess voice solutions not on line rental or per-minute costs, but on flexibility, quality of service (QoS), and integration with CRMs or support platforms.
Network Traffic: Fixed Line Still Carries Weight
Interestingly, despite the overall decline in fixed line voice subscriptions, fixed line network traffic increased by 8.12%, suggesting that those who still use landlines are using them more intensively.
This could be driven by specific use cases, such as call centres or VoIP trunking services that still route traffic through fixed line infrastructure in hybrid systems.
From a VoIP provider perspective, this highlights a continued need for reliable fixed line interconnects and termination agreements. Even in a cloud-first world, interconnection with legacy networks remains important — particularly when servicing larger enterprises or government clients.
Consumer Behaviour: Data Over Dial Tone
The consumer calling landscape has also shifted in terms of how people communicate. The ICASA report points out a 5.03% increase in mobile data subscriptions and a 12.64% growth in machine-to-machine (M2M) mobile subscriptions, underscoring the shift from voice to data-centric services.
Younger consumers and digitally native businesses are skipping voice altogether in favour of apps like WhatsApp, Microsoft Teams, Zoom, and Slack. While these platforms aren’t traditional VoIP, they represent the same core shift: voice is now just one part of a larger, integrated communications strategy.
What This Means for VoIP Providers and Businesses
The message is clear: investing in VoIP is no longer just an upgrade — it’s a strategic move.
Here’s why:
1. Cost control
VoIP typically offers better call rates, especially for international or inter-branch calls.
2. Scalability
You can add users or features without installing new lines.
3. Mobility
With mobile and softphone apps, staff can work from anywhere.
4. Integration
VoIP platforms integrate with CRMs, call tracking tools, and support desks — something traditional systems can’t do.
For VoIP service providers, VoIP calling trends show us that the opportunity lies in educating SMEs and mid-sized firms on the benefits, offering value-added services, and ensuring reliability through strong SLAs and failover infrastructure.
Comparing Fixed Line vs VoIP and Mobile Trends (2024–2025)
| Metric | 2024 | 2025 | % Change | Implication |
|---|---|---|---|---|
| Fixed Line Subscriptions (million) | 1.47 | 1.35 | -7.94% | Declining usage, especially in residential markets |
| Fixed Line Network Traffic (minutes) | ~4.1 billion | ~4.5 billion | +8.12% | Higher usage by enterprise, government, etc. |
| Fixed Broadband Subscriptions (million) | 3.5 | 3.62 | +3.43% | VoIP-enabling infrastructure continues to grow |
| Mobile Subscriptions (million) | 111.5 | 116.0 | +4.04% | Multi-SIM behaviour and mobile dominance |
| LTE & 5G Devices | ~33 million | ~38 million | +13.97% | Faster networks boosting mobile and VoIP calls |
💡 What This Means for Consumers
The numbers tell a compelling story. Fixed line services are shrinking, but haven’t vanished. Enterprise use is holding the line—so to speak—due to internal needs for stability, QoS, or compliance. Yet, even those businesses are shifting rapidly toward hosted PBX and SIP trunking solutions.
On the consumer side, fixed lines are nearly obsolete. Mobile and VoIP apps (like WhatsApp, Microsoft Teams, and Zoom Phone) have redefined how people interact. Cost-conscious users are routing calls via Wi-Fi or mobile data instead of traditional voice networks.
This is creating a tipping point where telecom providers must reimagine their offerings:
Invest in VoIP-ready fibre packages
Phase out legacy landline infrastructure
Offer cloud calling solutions integrated with digital tools
Create pricing bundles that reward mobile-data-driven calling
VoIP Calling Trends: The Momentum Is Just Getting Started
We are firmly in the post-landline era, and VoIP is no longer a fringe technology. It’s the default voice platform for new businesses, digital-first teams, and anyone seeking cost-efficiency with rich feature sets.
The coming years will likely see more:
Consolidation between ISPs and VoIP providers
Voice and video bundled as one collaboration suite
Voice traffic fully migrating to data-first platforms
With broadband infrastructure expanding and mobile substitution reaching saturation, VoIP calling trends tell us that VoIP is poised to be South Africa’s voice platform of the future.
Fixed line usage continues to decline, but still serves niche needs. Meanwhile, VoIP — bolstered by broadband growth and cloud-first business models — is taking centre stage.
As mobile networks get faster and more stable, and as fibre access expands, VoIP adoption is only going to accelerate. Providers who can offer cost-effective, flexible, and high-quality calling solutions will be well-placed to lead this transformation.
If you’re still hanging onto your landline, it might be time to ask: what’s holding you back?
