Most IoT devices do not need full 5G. Low-power sensors are better on LTE-M or NB-IoT, mid-range devices on 4G Cat 1 today and 5G RedCap as it matures, and only high-bandwidth or low-latency devices such as CCTV and industrial gateways need full 5G. RedCap needs 5G standalone, and many IoT SIMs do not yet get standalone on UK networks.
The IoT industry has spent years being told that 5G will connect everything. The truth is more interesting. 5G is a family of technologies, and for most machines the right member of that family is not the one with the big speed test numbers.
Match the radio to the job
| Technology | Good for | Speed | Power | UK status |
|---|---|---|---|---|
| NB-IoT | Meters, simple sensors, deep indoor | Very low | Lowest | Available, coverage varies by network |
| LTE-M | Trackers, alarms, wearables, anything that moves | Low | Very low | Available on major networks |
| 4G Cat 1 / Cat 1 bis | Telemetry, payment, small gateways | Moderate | Moderate | Everywhere 4G is |
| 5G RedCap | Mid-range devices that want 5G features | Moderate to good | Lower than full 5G | Needs standalone; early days |
| Full 5G | CCTV, gateways, vehicles, industrial routers | High | Highest | Widely available |
NB-IoT and LTE-M are formally part of the 5G standards for massive IoT, so a device using them is arguably already “5G”. It just does not say so on the box.
RedCap: the 5G that IoT was waiting for
RedCap, short for Reduced Capability, strips 5G down: fewer antennas, narrower bandwidth, simpler modems, lower cost and better battery life. It is aimed at the middle ground where LTE-M is too slow and full 5G is overkill. There is a full explainer in what is 5G RedCap, and a real example of a RedCap router in the Teltonika RUT276.
The catch is that RedCap only works on 5G standalone. So a RedCap device needs standalone coverage, a SIM that is allowed onto the standalone core, and a provider that supports it. Plenty of IoT SIMs on the market do not yet tick all three. Until they do, a RedCap device may fall back to 4G or not connect at all, depending on its design. Check before you build a product around it.
When full 5G makes sense
- CCTV and video analytics uploading continuously.
- Industrial gateways aggregating many devices.
- Vehicle and rail connectivity carrying passenger and operational traffic.
- Remote control and robotics, where steady low latency matters, which really means standalone.
The SIM matters as much as the module
IoT devices are often deployed somewhere and left. That makes the SIM strategy critical:
- Multi-network access keeps devices online when one network has a fault or a gap. See multi-network SIMs.
- Roaming SIMs from overseas providers work in the UK, but face roaming limits, including restrictions on 2G and 3G and, in some countries, on permanent roaming.
- eSIM lets you change network over the air. The SGP.32 standard reached commercial availability in 2026 and is designed specifically for devices with no screen. See eSIM and 5G.
Plan for the switch-offs
3G has already gone in the UK. 2G is on borrowed time: every UK network has committed to switching it off by 2033, and some have said they will start well before. Any device still relying on 2G as a fallback needs a plan. The details are in the 2G and 3G switch-off guide.
Questions people ask
What is 5G RedCap?
Reduced Capability 5G: a simpler, cheaper, lower-power version of 5G designed for mid-range IoT devices such as wearables, trackers and small routers. It needs a 5G standalone network.
Will LTE-M and NB-IoT be switched off?
No UK network has announced an LTE-M or NB-IoT switch-off. They are part of the 5G family of standards for massive IoT and are expected to run for many years.
Do IoT SIMs work on 5G standalone in the UK?
Some do, many do not yet. Standalone access depends on whether the SIM provider has it agreed with the UK network, and roaming IoT SIMs rarely get it.