Back in October 2021, I wrote a post on The 3G4G Blog asking Are there 50 Billion IoT Devices yet? The question went back to one of the best-known predictions from the early days of the Internet of Things: that there would be 50 billion IoT devices by 2020. That number referred to the wider IoT universe, not just cellular IoT. The devices could be connected using cellular networks, Wi-Fi, Bluetooth, Zigbee, LPWA technologies and many other forms of connectivity.
When I looked at the numbers in 2021, the reality was very different. GSMA estimated 13.1 billion IoT connections in 2020, of which around 1.9 billion were cellular. Ericsson estimated 12.4 billion IoT devices, including around 1.6 billion cellular IoT connections, while Transforma Insights put cellular IoT at around 1.55 billion connections in mid-2021. Five years later, the picture is clearer, although IoT counting remains anything but simple.
Transforma Insights estimates that there were 21 billion active IoT devices globally at the end of 2025, rising to 48 billion by 2035. So, interestingly, the market may eventually get very close to that famous 50 billion figure, just around 15 years later than originally expected. Transforma Insights The accompanying Transforma forecast presentation shows the same progression from 21.0 billion in 2025 to 48.0 billion in 2035.
Most of those devices are not cellular. Transforma estimates that short-range technologies such as Wi-Fi, Bluetooth and Zigbee account for around 79–80% of IoT connections. Cellular represents 11.3% of the total in 2025, or about 2.4 billion devices, increasing to 14.1%, or 6.8 billion, by 2035. The remainder includes non-cellular LPWA, satellite and other technologies. Transforma Insights The presentation also breaks the cellular component down across 2G, 3G, 4G, 5G mMTC and 5G non-mMTC technologies.
There is, however, an important complication. Berg Insight estimates that there were 4.2 billion cellular IoT connections at the end of 2025, significantly higher than Transforma's 2.4 billion figure. Berg forecasts this reaching 6.5 billion in 2030.
This is a good reminder that IoT numbers depend heavily on what is being counted and how. Transforma builds its forecasts from active devices and individual applications, whereas mobile operators commonly report IoT SIMs, cards, terminals, managed connections or M2M accesses. These measures are not necessarily equivalent. That distinction becomes particularly obvious when looking at individual operators. The three Chinese operators alone currently report more than 3 billion IoT connections, already more than Transforma's 2.4 billion estimate for the entire global active cellular IoT device base at the end of 2025. The numbers therefore should not be mixed as though they measure precisely the same thing.
With that caveat, it is nevertheless fascinating to see the scale of IoT connectivity being managed by the world's largest mobile operators. Based on the latest available operator reporting and estimates, this is how the largest cellular IoT and M2M connectivity providers currently compare:
| Rank | Operator | Reported/estimated cellular IoT / M2M connections |
|---|---|---|
| 1 | China Mobile | 1,511 million |
| 2 | China Telecom | 806 million |
| 3 | China Unicom | 772.6 million |
| 4 | Vodafone | 244 million |
| 5 | AT&T | ~150–160 million |
| 6 | Bharti Airtel India | 86.06 million |
| 7–9 | Verizon | ~62–69 million |
| 7–9 | Deutsche Telekom | ~62–69 million |
| 7–9 | Telefónica | 64.74 million |
| 10= | KDDI | ~60.6 million |
| 10= | Orange | 60.49 million |
Approximate figures based on latest available operator reporting and estimates, 2025–2026. Definitions vary by operator.
China Mobile is in a completely different league from most operators. At the end of June 2026 it reported 1.511 billion IoT card connections, alongside 1.011 billion conventional mobile customers. In other words, China Mobile now has roughly half a billion more IoT card connections than mobile customers.
There is also a nice connection back to my 2021 post. Transforma Insights told me at the time that there were around 1.55 billion cellular IoT connections globally. China Mobile alone now reports 1.511 billion IoT card connections, almost the same number. Again, the definitions are not directly comparable, but it gives some indication of just how dramatically the scale of operator IoT connectivity has changed.
China Telecom is second. Its first-half 2026 results show 806 million IoT connected devices, up from 746 million at the end of 2025. That means it added around 60 million connected devices in just six months.
China Unicom follows closely with 772.608 million IoT terminal connections at the end of June 2026.
Together, China Mobile, China Telecom and China Unicom now report approximately 3.09 billion IoT connections. There is then an enormous gap to the largest operator outside China.
Vodafone reports 244 million IoT connections, making it comfortably the largest Western cellular IoT connectivity provider. Vodafone's scale is particularly notable because its IoT business is international and extends well beyond the countries in which Vodafone operates its own mobile networks.
AT&T comes next. The operator said in March 2026 that it connects 150 million devices across major industry sectors and connects more than 80% of connected cars in the US. Berg Insight estimated AT&T's cellular IoT base at 160 million at the end of 2025. Given the difference in wording and methodology, showing this as approximately 150–160 million seems more sensible than choosing one supposedly precise number.
India is another market where M2M connectivity is expanding rapidly. According to TRAI's August 2026 data, India had 140.50 million M2M cellular mobile connections, up from 137.70 million a month earlier. Bharti Airtel accounted for 86.06 million, representing 61.25% of the market. Reliance Jio had 27.10 million, Vodafone Idea 22.57 million and BSNL 4.78 million. That puts Airtel India comfortably in sixth place globally. Berg Insight had estimated Airtel's IoT base at 69 million at the end of 2025, so the growth during 2026 has been substantial.
The next three operators are much harder to order precisely. Berg Insight estimates that Verizon and Deutsche Telekom each had somewhere between 62 and 69 million cellular IoT connections at the end of 2025. Telefónica provides a more recent and precise number. It reported 64.739 million IoT accesses at the end of June 2026, up from 44.052 million a year earlier, an increase of 47%. Much of the increase came from Spain, where new IoT lines associated with connected roadside-assistance beacons drove particularly rapid growth.
Given the overlap between these figures and their differing reporting dates and definitions, I have grouped Verizon, Deutsche Telekom and Telefónica together as positions 7–9, rather than suggesting that we can confidently distinguish between them.
The final place is effectively a tie between KDDI and Orange. KDDI reports 60.632 million "Connected Solutions" managed connections for FY2025, with a target of 80 million by FY2028. This is a broader managed-connections KPI rather than a perfectly clean cellular IoT SIM count, so again it needs to be treated with some caution. Orange provides one of the clearer definitions. At the end of June 2026 it reported 60.491 million M2M accesses. Orange defines M2M as SIM cards dedicated to exchanging information between machines through one or more communications networks.
The numerical difference between KDDI and Orange is tiny compared with the difference in definitions, so treating them as joint tenth is more meaningful than declaring one definitively larger than the other.
The technology underneath these connections is changing as well. Transforma Insights estimates that there were 487 million cellular-based IoT device shipments during 2025, rising to around 1.2 billion annually by 2035. In 2025, 4G accounted for 46% of shipments, while 5G mMTC accounted for 48%, mainly reflecting the huge Chinese NB-IoT market. By 2035, Transforma expects 5G mMTC to account for 64% of cellular IoT shipments and 5G non-mMTC for another 27%, while 4G falls to just 9%.
The comparison also highlights why I excluded M2M and IoT when recently looking at the world's largest mobile operators by conventional subscriber numbers. China Mobile's 1.511 billion IoT cards, Vodafone's 244 million IoT connections and Airtel India's 86 million M2M connections would substantially distort any ranking intended to show the number of people subscribing to mobile services.
It also brings us back to the question I asked in 2021. No, we did not have 50 billion IoT devices in 2020. Even today, Transforma Insights estimates the global total at around 21 billion, although it now expects the market to reach approximately 48 billion by 2035. But cellular IoT has nevertheless grown enormously. Depending on which methodology is used, the global cellular IoT base at the end of 2025 was somewhere between Transforma's 2.4 billion active devices and Berg Insight's 4.2 billion cellular connections. That gap is itself an important lesson: whenever somebody quotes an IoT number, it is worth asking exactly what is being counted.
What is beyond doubt is that IoT is now operating at extraordinary scale. China Mobile alone manages more than 1.5 billion reported IoT connections, the three Chinese operators together report more than 3 billion, and operators around the world are supporting tens or hundreds of millions of connected cars, smart meters, trackers, payment terminals and other machines.
The 50 billion prediction may have been far too optimistic on timing, but the IoT market certainly did not disappear. It just took a rather different path to the one many people imagined fifteen years ago.
Related Posts:
- Operator Watch Blog: The World’s 10 Largest Mobile Operators by Subscriber Numbers in 2026
- Operator Watch Blog: A Billion for China and China Mobile
- Operator Watch Blog: World's Largest Mobile Networks by Data Traffic - Q1 2024
- Operator Watch Blog: 8.05 Billion Mobile Subscribers with 5.22 Billion Unique by End of 2020
- Operator Watch Blog: World's Largest Mobile Networks by Data Traffic - March 2021
