IoT SIM or phone SIM for a device?

A phone SIM will often work in a router or a camera, at least for a while. The trouble starts later: terms that do not allow it, a SIM tied to one network, a monthly bill for something that sits in a drawer, and a device that stops working the day a bundle runs out. An IoT SIM is built for the job a device actually does.

What a phone SIM is designed for

A consumer SIM assumes a person with a phone. Its price assumes a handset, its allowance assumes a person's browsing, and its terms often limit or forbid use in routers and other devices. It is locked to one network, so a device in a spot where that network is weak simply has a weak connection. And it is billed every month whether the SIM is used or not.

None of that matters for a phone. All of it matters for a camera on a building site, a card machine at a market, or a tracker in a van.

What an IoT SIM does differently

	Phone SIM	ThingSIM IoT SIM
Networks	One	All four UK networks (O2, Vodafone, Three, EE), or three for less
Billing	Every month from purchase	Only while the SIM is switched on
At the allowance	Throttled, cut off or overage	Pauses; upgrade or wait for the reset
Contract	Often 12 to 24 months	None; monthly or annually
Device use	Often limited by the terms	What it is for
Remote management	None	Portal and API

The multi-network part is the one most people underestimate. A ThingSIM UK 4-network SIM uses whichever network is strongest where the device is, so a camera on the edge of one network's coverage is not stuck with it.

Paying only for what is switched on

SIMs arrive inactive and cost £2.00 each, once. Billing for a SIM starts the day you switch it on in the portal, so a drawer of spare SIMs costs nothing until each one goes into service. When a device is retired, cease its SIM and the charge stops. See how ThingSIM billing works for the detail.

Sizing it properly

Most devices use far less data than a phone. A card machine or alarm communicator often fits comfortably in 50 MB a month; a router or a camera that uploads video needs much more. The data guide works through the common devices. Plans run from 50 MB at £0.90 a month on UK 4-network to 5 GB at £8.85.

When a phone SIM is fine

For a one-off test on your desk, a spare phone SIM is a quick way to check a device connects. For anything installed and left to run, use a SIM designed for it.

Common questions

Can I put a ThingSIM SIM in a 4G router?

Yes. That is one of the main things it is for. The APN for each SIM is shown against it in the ThingSIM portal; see setting the APN.

Does a ThingSIM SIM do SMS?

Yes. SMS is supported, which matters for trackers and alarm communicators that are configured or report by text.

What happens if my device uses more data than I expected?

The SIM pauses at its allowance instead of running up a bill. You can move it to a larger plan straight away, paying only the difference for the rest of the month, or wait for the allowance to reset.