2G and 3G switch-off and your devices

UK mobile networks have switched off 3G, and 2G is set to close by 2033 at the latest. A device that can only use those networks will stop connecting when they go, however good its SIM. The SIM cannot add a radio the device does not have, so the work is in knowing what your devices can actually use.

Find out what the device's modem supports

Everything depends on the cellular modem inside the device. Check its specification for the network technologies it supports:

2G only (GPRS, EDGE): at risk when 2G closes.
3G (UMTS, HSPA): no longer usable for 3G; it may still fall back to 2G until that closes.
4G (LTE): the current mainstream for devices.
NB-IoT: a low-power 4G-family technology for devices that send small amounts of data.

Older alarm communicators, telemetry units, trackers and lift lines are the usual places to find 2G and 3G modems. If the specification is unclear, the model number and the manufacturer's support pages usually settle it.

Audit before anything stops

For an estate of more than a handful of devices, a simple inventory turns a vague worry into a plan:

Record	Why it matters
Device and model	Identifies the modem
Supported technologies	2G, 3G, 4G, NB-IoT
Location and access	Some devices are hard to reach to replace
Does it need voice or SMS?	Changes what the replacement must support
Owner and supplier	Who replaces or reflashes it
Replacement date	So it happens before a failure, not after

Devices that are hard to reach, or that do something safety-related, go to the top of the list.

What to replace with

A replacement device should support 4G, and for low-power, low-data devices NB-IoT is worth considering because it is built for long battery life and deep coverage. ThingSIM SIMs support 4G data, NB-IoT and SMS. If the device needs a voice path, check that separately with the device supplier, because a data SIM alone does not provide one.

Most telemetry devices use very little data. 50 MB on UK 4-network is £0.90 a month, and the multi-network roaming helps devices in awkward locations. See how much data your device needs to size it.

Common questions

Will a new SIM keep my 2G or 3G device working?

No. The limit is the device's modem, not the SIM. A device that only supports 2G or 3G needs replacing or upgrading to a 4G or NB-IoT model.

Do ThingSIM SIMs support NB-IoT?

Yes. ThingSIM SIMs support NB-IoT as well as 4G data and SMS.

Which devices are most likely to be affected?

Older alarm communicators, telemetry and metering units, trackers and lift lines. Check each model's supported technologies and record them in an inventory.