The SIM Inside Your Payment Terminal Is a Bigger Retail Decision Than It Looks

A company opens a new retail outlet near an international border and assumes the same cellular payment terminals that have worked reliably inland will work just as well in the new location.

But they don’t.

As mobile networks from neighbouring countries come into range, connections become unreliable and terminals repeatedly lose service. Yet when engineers investigate, they discover something strange: there is a perfectly good local network available. The terminals are simply refusing to connect to it because of a fundamental connectivity question that wasn’t asked long before those terminals ever reached the store.

This is just one real-world example (more on it later) of how decisions made about cellular connectivity before deployment can determine which networks a payment terminal can use, which countries it can operate in – and even whether its owner remains free to change connectivity providers five years down the line if requirements change.

It’s the difference between a frictionless checkout and a customer who cannot pay.

And cellular connectivity decisions like this are about to matter to a lot more retailers.

According to Berg Insight, 54 per cent of all POS terminals shipped globally in 2024 incorporated cellular connectivity. The installed base reached around 166 million terminals that year too, and is forecast to hit 247 million by 2029.

There are compelling reasons for this growth. Cellular frees payment terminals from hard-wired and therefore ‘tethered’ Ethernet, while reducing their dependence on store Wi-Fi – an environment the payment provider neither owns nor controls.

Cellular also enables terminals to move. Restaurants can take payments at the table, delivery drivers can accept cards at the customer’s door, and pop-up stores can trade from almost anywhere.

But as cellular payment terminals proliferate, there is an important distinction many retailers and payment providers may not realise.

The cellular connectivity increasingly powering payment terminals isn’t necessarily the same as the consumer connectivity we know from smartphones. The payments industry isn’t just moving to cellular. It is increasingly moving to a different class of cellular connectivity called cellular IoT.

A different cellular built for machines, not people

Cellular IoT – IoT being short for ‘Internet of Things’ – uses the same underlying cellular infrastructure as smartphones but is designed around the very different requirements of large fleets of connected machines and devices.

These machines range from smart meters and vehicle trackers to payment terminals. These typically need to exchange small amounts of data periodically but reliably, operate unattended, and be remotely managed in fleets of thousands or hundreds of thousands of devices.

And there is considerably more to getting cellular IoT right than choosing a consumer mobile network and price plan and putting a SIM into a device.

When used in a front-line, business-critical device such as a payment terminal, decisions around network access, network selection, diagnostics, eSIM architecture and long-term supplier flexibility can affect how reliably terminals operate today – and how much freedom their owners retain tomorrow.

The deployment timescales are different too. Cellular IoT devices typically remain deployed for a decade or more, during which time networks, standards, security requirements, markets and commercial arrangements may all change.

Yet a connectivity decision made on day one can be surprisingly difficult to reverse in year three. This is where telecoms vendor lock-in becomes a serious commercial risk.

Depending on how the SIM, eSIM and connectivity architecture are configured, a payment provider can discover years after deployment that changing connectivity supplier is not simply a matter of signing a better contract. The underlying technical architecture itself may restrict its ability to move.

That can affect negotiating power, pricing, network choice and even expansion into new emerging markets if the existing provider cannot provide the connectivity required.

That makes decisions taken before deployment much more important than they initially appear. And because retailers and payment providers cannot be expected to be cellular IoT experts, the key is knowing what questions to ask.

Five questions to ask before deploying

1. ‘Exactly which mobile networks can my terminals use?’

‘Global coverage’ does not necessarily mean access to every network in a country. Access to multiple suitable networks provides greater resilience when coverage varies or one operator experiences problems.

2. ‘Can my terminal choose the best available network?’

Some cellular IoT arrangements steer terminals towards preferred operators, even when another available network could provide a more reliable connection. Payworld Belgium encountered precisely the kind of border problem described at the beginning of this article until its terminals were freed from network steering.

3. ‘Can we see what is happening on the network?’

When UK payment provider Dojo set out to push its payment performance beyond industry benchmarks, deep network-level analysis surfaced subtle factors involving Android networking behaviour, modem configuration and interactions with mobile networks.

Ask what network-level information you can access yourself across the fleet. If the answer is simply ‘raise a support ticket’, see this as a red flag if you are managing thousands of terminals.

4. ‘If I want to change provider in five years, can I?’

eSIM sounds like freedom because connectivity can be provisioned remotely. But depending on how it is implemented, the original cellular IoT connectivity provider may still control which connectivity profiles can be added and how they are changed. Find out before deployment, not afterwards.

5. ‘What happens when networks and standards change?’

The retirement of 3G networks worldwide provides the obvious warning. Networks close, standards evolve and roaming arrangements change. If connectivity cannot adapt remotely, an external network decision could ultimately leave a retailer replacing SIMs – or even terminals – across thousands of locations.

Connectivity is becoming part of the retail experience

This complexity is why specialist cellular IoT providers such as Onomondo have emerged alongside traditional mobile operators, offering connectivity built for fleets of machines with greater network visibility and control.

But the wider lesson is vendor neutral.

Retailers and payment providers don’t need to become telecom engineers. They do need to recognise that connectivity can influence where terminals work, how reliably they transact, how easily businesses enter new markets and whether they remain free to change suppliers.

The SIM may be almost invisible. But the decisions behind it can determine who controls your connectivity for years to come. Make sure it’s you.