# A 4G data SIM for a card machine > Choose a small data plan for a compatible payment terminal and test it at your stall, event, van or delivery stop. Use-case guides · 19 February 2026 For a compatible card machine sending payment data, start with UK 4-network 50 MB at £0.90 per active SIM per month. Payment messages are small, but the whole terminal's use matters, including updates and any other equipment sharing its connection. Check with your payment provider that the terminal accepts a separately supplied data SIM before ordering. A stall, van or delivery terminal needs to connect where the transaction takes place. ThingSIM UK 4-network roams across O2, Vodafone, Three and EE and uses whichever is strongest where the device is. That gives moving equipment more network options without choosing a single operator for every stop. ## Check with the payment provider first Ask for the exact terminal's SIM requirements and configuration instructions. Confirm whether you can change its mobile data settings yourself or need the provider to do it. The SIM supplies connectivity; your payment provider remains responsible for the payment service and the terminal's approved setup. Confirm the required physical SIM size or explicit eSIM support. ThingSIM physical cards pop out to mini, micro or nano. An eSIM arrives as a QR code minutes after ordering, but only choose it when the terminal supports the installation method. Either format costs £2.00 per SIM once. ThingSIM supports SMS. Whether the terminal uses SMS for setup or another function is a question for the terminal provider. Do not assume that SMS support makes a payment feature available, and do not copy configuration commands intended for a different model. ## A pre-trading checklist 1. Confirm that the terminal accepts your own data SIM and get the provider's setup instructions. 2. Order the correct format ahead of the event or first delivery round. Physical SIMs are posted to UK and EU addresses; allow for delivery in your schedule without assuming a particular arrival date. 3. Match the installed SIM to its portal record and activate it when you are ready to test. Billing starts on activation, not when the SIM arrives. 4. Enter the APN shown against the SIM in the ThingSIM portal using the terminal's supported configuration process. 5. Run the payment provider's approved connection or transaction test. Check the result in the relevant payment system rather than relying only on signal bars. 6. Repeat the test at the actual trading position, including inside the van or stall if that is where payments happen. 7. Check portal usage after a representative trading period and confirm that the allowance leaves room for expected updates. Keep the SIM reference and provider contact details with your trading kit. If a payment fails, knowing whether the terminal has working data helps you describe the issue to the right support team. ## Plan for a busy venue Multi-network access is useful when the best available network differs between venues. It does not turn a pre-opening test into a guarantee about every transaction later in the day. Test at relevant times where possible and agree with your payment provider how staff should respond to a connection failure. Keep the terminal in its intended operating position during the test. A successful connection outside a vehicle does not demonstrate the same result inside it. If it uses a separate mobile router, test the full path from the terminal through that router to the payment service. The [payment terminals page](/sectors/payment-terminals) covers this use case. For temporary installations, [connecting event kit](/connecting-event-kit) includes activation and packing-up checks that are easy to miss when setting up quickly. ## Keep the allowance focused on payments A 50 MB plan is a starting point for small payment messages, not a promise about every terminal. Ask the supplier for its expected data use and update requirements. If the SIM is in a shared router, count every connected device rather than assigning the terminal's estimate to the whole connection. Avoid putting staff browsing, camera uploads and payment traffic into one estimate without separating them first. [How much data a device needs](/how-much-data-does-my-device-need) explains how to turn measured use into an allowance. ThingSIM also offers 250 MB, 1 GB and 5 GB when the complete workload needs more. Check usage in the portal before an important trading day. When a SIM reaches its allowance, it pauses instead of charging overage. You can move it to a larger plan immediately, paying only the difference for the rest of the month, or wait for the reset. ## Order for the way you trade Order up to 25 SIMs online by card; larger fleets go through [fleet enquiries](/contact?topic=fleet). SIMs arrive inactive, which lets you prepare spare kit before it is needed. Pause an unused SIM between jobs, but keep it active whenever you expect the terminal to be ready for payments. There is no contract, with monthly card billing or twelve months paid up front without a discount. See [billing explained](/iot-sim-billing-explained) and [help](/help) for account details. ## Common questions ### Will ThingSIM work in every card machine? Check with the payment provider before ordering. The terminal must accept a separately supplied SIM and support the required configuration. ### Is 50 MB enough for payments? It is a starting allowance for small payment messages. Include terminal updates and any shared-router traffic, then check actual usage. ### Does the SIM include the payment service? No. ThingSIM supplies SIM connectivity, while your payment provider supplies the payment service and terminal support. ## Recommended plan 50 MB, UK 4-network: £0.90 a month per active SIM, ex VAT. Source: https://thingsim.com/card-machine-4g-sim