# LTE-M vs NB-IoT: which low-power network for your device?

> How LTE-M (Cat-M) and NB-IoT differ in data rate, mobility, voice and battery life, which suits trackers, meters or sensors, and how to check your device.

Choosing a SIM · 27 October 2026

LTE-M and NB-IoT are the two low-power cellular technologies built for IoT devices that send small amounts of data and run for years on a battery. Both are part of the 4G family, both reach places ordinary 4G struggles with, and every ThingSIM supports both. Which one a device uses is decided by its modem, so the choice is really a choice of device.

## The short version

| | LTE-M (Cat-M1) | NB-IoT |
|---|---|---|
| Data rate | Higher: enough for firmware updates and frequent reports | Very low: small, infrequent messages |
| Moving devices | Handles movement between cells | Best for devices that stay in one place |
| Voice | Possible (VoLTE) on supporting devices | No |
| Latency | Lower | Higher |
| Battery life | Long | Longest |
| Coverage in buildings and underground | Better than standard 4G | Deepest |
| Typical devices | Trackers, wearables, alarm communicators, vending | Meters, level and environmental sensors, parking sensors |

## When LTE-M is the better fit

Choose an LTE-M device when it moves, needs to respond quickly, sends more than a few readings a day, or needs firmware updates over the air without taking hours. Asset trackers and anything that might need a voice path are the classic cases.

## When NB-IoT is the better fit

Choose an NB-IoT device when it stays put, sends small readings infrequently, and must run for years on a battery, often somewhere radio struggles to reach: a meter in a basement, a sensor in a manhole, a logger in a plant room.

## Check the device, not the SIM

The SIM does not decide which technology is used; the device's modem does. Look in the specification for "LTE Cat-M1" or "Cat-M" and "NB-IoT" (sometimes "Cat-NB1" or "Cat-NB2"). Many modules support both, plus standard 4G as a fallback. Confirm with the device supplier how it is configured to use them in the UK before a large deployment.

## Data use

Both suit small plans. Most low-power sensors and meters fit the 50 MB plan, at £0.90 a month on UK 4-network; see [how much data your device needs](/how-much-data-does-my-device-need).

## Common questions

### Does ThingSIM support LTE-M and NB-IoT?

Yes. Every ThingSIM supports LTE-M and NB-IoT as well as 4G data, 2G and SMS. The device's modem decides which it uses.

### Is LTE-M the same as Cat-M1?

Yes. LTE-M is the common name for the LTE Cat-M1 category, sometimes shortened to Cat-M.

### Which is better for a GPS tracker, LTE-M or NB-IoT?

Usually LTE-M, because trackers move between cells and often need to report more often than NB-IoT is designed for. See [choosing a SIM for a GPS tracker](/sim-for-gps-tracker).

### Is NB-IoT the same as 5G?

NB-IoT and LTE-M are 4G-family technologies that are also recognised as part of 5G's plans for massive IoT, so devices built for them are expected to remain usable as networks move on.

## Recommended plan

50 MB, UK 4-network: £0.90 a month per active SIM, ex VAT.

Source: https://thingsim.com/lte-m-vs-nb-iot