iSocket Is Suitable For Prepaid SIM Cards

Posted , by Denis Sokol (Last update )

NOTE! This is old article

Since 2021 we offer new Plug-and-Go hassle-free iSocket with integrated connectivity - it works out of the box and can solve all the problems that we have been helping clients solve for the last 10+ years: remote power outage alarm monitoring, vaccine storages temperatures monitoring, remote reboot for equipment, break-in, flood, fire, gas leak and other notifications, and more. Just one new amazing iSocket! With new energy metering capabilities. You can order it from

This article is a good example of how much trouble our customers and our support have had with SIM cards. This is the main reason why we are introducing the hassle-free Plug-and-Go iSocket technology in 2021.

This is a re-post of old articles that have changed because of updates in the mobile world. I have split this article into several different posts. Here I tell basic information about the use of prepaid SIM cards in iSocket. Sometimes these cards called PAYG or Pay-As-You-Go cards. If you are from USA or Canada, read this post [link removed, old article] about specific for SIM cards for USA and Canada. The information below will be useful for you too.

You must disable any voicemail or call-forwarding services for your subscription or prepaid card! Please ask your mobile operator for help if necessary.

Some users have approached us about problems with prepaid cards. We have tested the device with prepaid cards of various operators in different countries. A common problem is that the device does not send a reply nor call back to the user when using prepaid cards. The explanation is simple: You have not activated your prepaid card!

For USA and Canada the customer activation process may be different from described in the next paragraph. Please read my post here [link removed, old article].

Some cards require activation by a call to customer support. If you insert one of these cards into the iSocket, the device will receive messages and incoming calls and will be able to execute commands, but you will not receive any responses. The problem is not with the device. If you were to insert the same card (new, but not yet activated) into your mobile phone and try to send an SMS, you will also get an error message. Please read the instructions for the prepaid card carefully and activate it, using your mobile phone. After you have activated the card, it can be used in iSocket.

Some prepaid cards require to be preset to accept calls and select the support service language required. Do this using your mobile phone according to the instructions for the prepaid card. You can then use the card in your iSocket.

You must disable any voicemail or call-forwarding services for your subscription or prepaid card! Please ask your mobile operator for help if necessary.

Note too that some prepaid cards do not allow you to send SMS’s at all, because this is not included in the tariff. If this is the case with your prepaid card, then iSocket will also be unable to send SMS’s. Check whether you can send SMS via your mobile phone with the same prepaid card.

Sometimes, prepaid cards have pre-stored numbers (for example the number to customer service). In very rare cases this can interfere with the normal operation of the phone. You can quite safely remove these numbers from the SIM-card without doubts. This can be done using your mobile phone.

Remember also to disable the PIN-code request. The POWER LED will indicate by specific blinking if you have not done so (see User Manual for the device). Disable PIN-code security using your mobile phone. If you have not done so and you turn on the unit three times you might have to reset the SIM-card PIN-code using the PUK-code.

To sum up: Activate your prepaid subscription according to the instructions, disable any voicemail or call-forwarding, ensure that you have sufficient credit on the SIM-card, disable PIN code security and the card can then be used in your iSocket.

Which is better? - prepaid or subscription (contract) service?

It is entirely up to you! A prepaid card, for example, might be convenient because you can buy it quickly and do not need to sign any contracts. From a financial point of view, there are no particular recommendations. Although prepaid cards have no monthly fee, it does have a validity period from activation or last recharge. If you don’t plan to use the device frequently, the limited validity period may be inconvenient. Read the terms of use carefully when buying a prepaid card.

On the other hand, some mobile operators provide contracts with a low monthly fee. If you choose this alternative you do not need to worry about the validity period. This small monthly fee could prove more economical and convenient for you.

Most but not all prepaid cards, and in some cases contract SIM cards, will be deactivated by the operator if you do not use it. They usually require to make at least one call or send at least one SMS during a certain period. To prevent deactivation of the SIM card for this reason you can send a message to the iSocket at least once a month or configure scheduler to send it for you. You also can request a call back from the iSocket unit. See more information about these features in the user manual [link removed, old article] for your iSocket.

Posted (Last update )


5.0 (based on 12 reviews)

iSocket for power outages monitoring in the United States and Canada

 From ordering to installing, everything went smoothly and gently. What an easy way to set up!

 From ordering to installing, everything went smoothly and gently. What an easy way to set up!

5.0 By from Belgium

A small cost for the peace of mind and comfort that iSocket gives you.

Remember, the cost of the damage from a power outage can be considerably more than the cost of a solution that will send you power outage notifications. And remember, power failure alerting is not the only feature iSocket offers you.