In the second quarter of Kenya’s 2025/26 financial year, total domestic mobile SMS traffic fell from 14.7 billion messages to 14.4 billion, a decline of 291 million messages in three months.
At the same time, total domestic voice minutes grew by 5.2%, rising from 29.9 billion to 31.5 billion minutes.
These two numbers moving in opposite directions in the same quarter, across the same subscriber base, tell a story about how people are communicating and what technology is driving the change.
Why Is SMS Falling?
The report from the Communications Authority states that the SMS decline is “probably due to growing uptake of internet-based messaging services.”
WhatsApp, Telegram, and similar applications run over data connections and offer features like images, voice notes, group chats, and read receipts that SMS does not.
For users on smartphones with a data connection, there is little reason to pay per SMS when an internet message is effectively free within an existing data bundle.
In the October-to-December quarter, the average mobile subscriber sent 61.1 SMS messages per month, down from 62.4 the previous quarter. Over the same period, the average subscriber made 133.9 minutes of calls per month, up from 127.5.
Smartphone penetration reached 92.9% of devices on Kenyan networks. That means nearly every mobile user in Kenya now has a device capable of running WhatsApp. The infrastructure for internet messaging is there, and the behavioral shift is following.
Why Is Voice Rising?
This is the more counterintuitive part. If smartphone and data penetration are rising, why are voice call minutes also rising rather than being replaced by video calls and internet voice?
Part of the answer is that mobile voice remains cheap and accessible. The average pay-as-you-go voice tariff across operators in this quarter was KES 3.47 per minute, which is modest and lower during off-peak hours.
Voice calls on mobile networks work even in areas with weaker data connections since they require no app installation, and they connect to anyone with a mobile number regardless of which messaging app they use.
Voice doesn’t have an interoperability problem; messaging apps do.
The usage figures also reflect the sheer growth in subscriptions. With 78.4 million SIM cards active in a country of 52.4 million people (a penetration rate of 149.5%), reflecting multiple SIMs per user, even modest per-subscription increases in call minutes translate to very large absolute minute counts.
There’s also a likely festive season effect. The October-to-December quarter encompasses the December holiday period, which drives increased communication across all channels.
This may have boosted voice minutes specifically, since family calls, which are often longer and more personal in nature, may be more likely to happen by voice than by text.
On-Net vs. Off-Net: The Competitive Picture
The breakdown between on-net calls (within the same network) and off-net calls (across networks) is telling. On-net voice traffic grew 4.4% to 26.2 billion minutes; off-net traffic grew a faster 9.1% to 5.3 billion minutes. Off-net SMS also grew 3.5% while on-net SMS fell 2.6%.
This pattern suggests that interconnection between networks is increasing relative to within-network traffic.
Off-net calls and messages have historically been more expensive than on-net ones due to termination fees, so their growth despite higher cost may indicate changing tariff structures, bundle offerings, or simply network diversification among users who hold SIMs from multiple operators.
Safaricom’s dominant position in voice traffic is notable: its 19.6 billion voice minutes in the quarter versus Airtel’s 11.8 billion gives it a 62.2% share of total domestic voice traffic.
In SMS, the gap is even wider as Safaricom accounts for 91.55% of all domestic SMS traffic, compared to Airtel’s 8.41%.
The SMS trajectory points downward, and there’s no structural reason to expect a reversal. As the remaining feature phone users (currently about 29.6 million devices) gradually transition to smartphones over the next few years, the base of users dependent on SMS as their primary messaging tool will shrink further.
The more interesting question is whether voice itself eventually follows SMS’s path. Internet-based voice (VoIP via WhatsApp calls, for example) already exists and is widely used, but it hasn’t yet displaced traditional cellular voice in the aggregate data.
The minutes-per-subscription figure is still rising. That could reflect durability of voice as a communication form, or it could be a lagged indicator, the same way SMS continued growing for a while after smartphones arrived before the internet messaging shift became visible in the numbers.
For now, what the data shows is a technology transition playing out in real time: one communication channel yielding to the internet while another holds its ground, at least for now.
