SIM/eSIM troubleshooting checklist

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Written by
Ken-Tristan Peterson

This article was updated on 26th April, 2022.

This blog post will help guide you through the first steps of the troubleshooting you can conduct on your own before escalating the issue to 1oT.

We’ve found that these steps fix most (if not all) of the problems encountered during the initial setup or from a random connection interruption.

We have categorized the troubleshooting into four different layers:

  • the SIM card itself,

  • the device,

  • roaming networks,

  • network infrastructure and more

Because there are many different layers involved, it's recommended to approach troubleshooting systematically.

Also, when going through the list, record your answers, so that you can quickly forward them to us. This helps to solve the problem promptly as 1oT support team will have more info.

SIM & Terminal

SIMs and eSIMs are very reliable and usually the issues are not related to the SIM itself. But a few things you should check from the SIM management side are:

  • Check the SIM/eSIM card is inserted correctly into the device.

  • Does the device recognize the SIM? Can the device read the ICCID number?

  • Is the SIM/eSIM in Live state in Terminal?

  • Check if the SIM has reached the data or SMS consumption limit.

  • Try resetting the SIM in 1oT Terminal.

    A SIM reset does a network-level refresh to the current subscription. It's always good to also make a hardware restart following the SIM reset.

    This action might take a while, wait for the pending action to complete.

    Keep in mind, that a device reset can push the device to find a new network. Sometimes, when there's no connectivity (network is down, there's no signal, etc.), then the device gets stuck and needs a reminder that other networks are available as well.


There is a difference between being registered to a network and having data connectivity. Often these two are considered the same.

Network registration means that the SIM is allowed to the network, you can send SMS messages once registered. Data connectivity comes into play after network registration, once you have allowed data (and roaming) on your device and set the correct APN.

  • Are you registered to the network?

    Check your device for network registration status.

  • Do you have data connectivity? Can you open a PDP context/data session?

    This is the process to start a data session from your device on the registered network.

    If you are having problems, make sure you are registered to the network first. Make sure the device configuration is correct, see Device section in this blog.

  • Are you able to send and receive SMS messages?

  • Try sending messages from Terminal and also from another device.

    The number (technically known as MSISDN) of the SIM/eSIM is displayed in Terminal. If you can send or receive SMS messages, you are registered successfully to the network. For data connectivity, you will need to open a PDP context/data session.

  • Is your preferred Radio Access Technology (2G, 3G, 4G, LPWAN) available?

    Make sure your SIM, roaming network and device support the technology you want to use.


If this SIM and device combination has worked before but not anymore, make sure you have not changed any configurations. Update the firmware to a previous version.

If it is a new device you are using for the first time with 1oT SIM/eSIM and you are experiencing issues, check the below items:

  • Have you set the correct APN settings?

    You can find APN settings for your SIM/eSIM in 1oT Terminal. Depending on the device, APN settings are applied differently, check your hardware documentation.

  • Is data allowed on your device?

  • Is roaming allowed on your device?

  • Have you restarted your device?

  • Have you tried using the SIM/eSIM in another device?

    Using the SIM/eSIM in a mobile handset is the easy way to verify the proper functioning of the SIM/eSIM.


eSIM with the default profile will act just like a regular SIM and all SIM troubleshooting and setup tips also apply for eSIM.

The only difference in eSIM is when it comes to transactions like download, enable and delete. If you are experiencing issues with one of these, make sure your device covers the next points.

  • Does your device support eSIM?

    Not all devices support eSIM. Devices that support eSIM might need to have some configuration applied. You can read more about it here.

  • Is SIM ToolKit enabled on the device?
    Learn what is SIM ToolKit.

  • Is BIP enabled on the device?
    See what is BIP.

Final tips!

You may have problems in places where general cellular coverage is weak. For example, basements, warehouses or remote areas.

Make sure the selected network covers your area. Coverage maps can be helpful in this. Some free and public resources are available from nPerf, Cell Mapper, and from the GSMA.

If you have gone through all the troubleshooting tips and you are still experiencing issues, make sure to contact our Customer Support team at

We encourage you to provide as much information as possible about your problem. 

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