We are here to help you get answers to your questions about OneSimCard phones and services.
When I try to make a call, I get a message 'Call is modified and cannot be made'. What does that mean?
Some phone models do not allow direct dialing with older OneSimCard SIMs sold before January 1, 2017.
To get around this problem, you should try either of these methods:
* is a star character located on the keypad
Other examples of how to use the *146* dialing prefix if necessary:
The prefix *146* and # at the end can be used from any phone. However, newer OneSimCard SIM do not require it and you should be able to dial codes directly, 091, 094, 095, 099 or 098XXXX*XX Talk.
If you have an older SIM and the dialing does not work without entering *146*, please follow these simple instructions to remove the need to dial *146*:
How to activate compatibility mode:
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 1. Locate OneSimCard Menu.
 On iPhones it is called SIM Applications menu and is located under Settings- Phone menu
     On Androids it is called SIM Toolkit app and it looks like one of the apps
Newer SIM Cards: Select Compatibility option and make sure "On" is selected
Older SIM Cards: After selecting Settings:
Bear in mind that if you have powered your telephone down, and have removed and reinstalled the battery, you will need to follow the programming steps outlined above, again.
When dialed directly, some Nokia and other phones can display message: "Call is not allowed" or "Call is barred". Just ignore this message and wait for the ring-back for 10 seconds or so.
What Is the Difference Between "Direct Dial" and "Callback Dial" calling?
Direct Dial calling allows the caller to enter the international call prefix, country calling code and telephone number and then be directly connected to the person they are calling. This is how you dial when using your regular mobile service. Direct Dial Calling is standard on the OneSimCard Europe & More, OneSimCard Universal and eSIM.
Callback calling also allows the caller to enter the international call prefix, country calling code and telephone number. After the called number is entered, the user immediately receives an incoming call connecting the user to person called. Callback is very simple to use and allows for low cost calling on the OneSimCard Plus and OneSimCard Expedition (formerly Data & Roam). Callback does not increase the connection time. It is the same as with Direct Dial.
The battery in my phone does not last long? It got fully drained during the flight to Europe. Why?
There can be a number of reasons why a battery does not hold a charge. Excluding the possibility of it being a faulty battery, there is another important factor to consider. If your phone is not registered on a roaming network, the battery will drain very quickly as the phone is constantly searching for a network to register on. So, if you get on a 6 hour flight and do not turn the phone off, or put it into airplane mode, by the time you land at the airport your battery will be drained and you will not be able to call back home.
The same thing will happen in those areas with spotty or weak signal network coverage - the battery will drain very fast. It is always a good idea to have an extra battery with you when you travel abroad.
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I have more than one Personal Extra Number (PEN). Can I use different PENs for OneSim VoIP?
If you have more than one OneSim VoIP enabled PEN you can switch between these PENs for the purpose of the OneSim VoIP account. This option is available in the My SIM Cards menu in your online account.I have an iPhone and am receiving charges for SMS sent to a UK mobile number 447786205094. Why?
This is a known issue with Apple's Facetime and iMessage applications on Apple iPhone devices. We recommend disabling Facetime and iMessage so it will not be able to automatically send SMS to this 447786205094 number. Any SMS sent to this number automatically by your phone can not be refunded by OneSimCard. Additional questions regarding iPhone applications and how they communicate should be directed to Apple Support.I am traveling in Saudi Arabia and can receive calls, but I can't make an outgoing call. What should I do?
Local carriers in Saudi Arabia sometimes block standard OneSimCard outgoing calls. If this happens you need to either (a) enter a compatibility code into the settings of your phone or (b) initiate your call by sending an SMS message from the regular SMS menu (not the OneSimCard menu) of your phone.
How To Activate Compatibility Mode:
Bear in mind that if you have powered your telephone down and removed and reinstalled the battery, you will need to follow the programming steps outlined above again.
How To Deactivate Compatibility Mode:
How To Dial Without Activating Compatibility Mode:
Initiate your call by sending an SMS message from the regular SMS menu (not the OneSimCard menu) of your phone.
For example, to call from Saudi Arabia to Boston USA you should go to the SMS menu of the phone and send a message:
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There are no special instructions to receive calls in these countries.
Can I check my Voice Mail from a phone other than my OneSimCard phone?
Yes. You can access the Voice Mail from other phones.I have a Samsung phone. When I dial following your instructions it does not work. What's wrong?
How to activate compatibility mode:
 1. Locate and Open "OneSimCard" Menu. ( It could  be displayed as STK Menu)
    2. Select "Settings"
Bear in mind that if you have powered your telephone down, and have removed and reinstalled the battery, you will need to follow the programming steps outlined above, again.
d when used with a OneSimCard.
I just activated my SIM card and can't make a successful test call. What's wrong?
If you just activated your SIM card and can not make a test call by following the instructions in the user manual, you will likely just need to power off the phone and power it back on again. The phone should automatically re-register with one of our partner networks. Remember, if you answer the test call when it rings you will be charged for the call.Do I need to have a OneSimCard SIM card installed in my phone to use OneSim VoIP?
No. OneSimCard SIM is not required to be installed in the phone for OneSim VoIP to be used. However, you do need to have OneSimCard account with a VoIP capable PEN.© 2006-2025 Belmont Telecom Inc., DBA OneSimCard.com. All rights reserved