We are here to help you get answers to your questions about OneSimCard phones and services.
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.Can I call using OneSim VoIP from countries where OneSimCard does not offer roaming coverage?
Yes. You can call from absolutely anywhere as long as you have a good Wi-Fi connection.How do I prevent the service from expiring?
The OneSimCard phone number has no expiration, provided you made at least 1 call or sent an SMS once every 12 months.
However, the funds on the SIM expire 10 months after your last recharge. The minimum recharge amount is $25. You can keep the balance from expiring by simply recharging at least once every 10 months. If you let your balance expire, then all you need to do to get the service up and running again is to log in and add funds to your SIM card. Automatic recharge will be canceled if you let your funds expire.
NOTE: For Physical 3-in-1Â DataMax & DataMax eSIM SIM cards, if the SIM card has no balance, the SIM will expire and be removed from the account after 7 days, unless there is a data package currently active on the SIM (not a future activation). If there is no balance on the SIM and the active data package expires, the SIM will expire 7 days following the expiration of the active data package.
Â
An expired SIM can be restored for a $10.00 restoration fee plus a recharge of at least $25.00.
Â
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.
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:
Â
 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.
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.Can I move balances from one SIM card to another?
We allow moving balances from one SIM card to another in the following cases:
Will a OneSimCard international SIM card work with my mobile phone?
OneSimCard will work with almost any unlocked GSM tri-band or quad-band cell phone. A partial list of compatible cell phones that we have tested can be viewed here.
If you need to unlock the phone, we suggest contacting your carrier or phone manufacturer for unlocking information or services.
If your phone is not a quad-band phone, please make sure that the bands of your phone are those required in the country of your travel. You can look it up here.
If you are still unsure whether your cell phone is compatible, contact support or purchase an international cell phone and SIM card bundle from us, which all come preloaded with our international SIM card, $10 balance and OneSimCard Apps Installed.
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.When I make a call using OneSim VoIP the quality of the call is not as good as the quality of the regular roaming connection. Can this be improved?
The quality of a OneSim VoIP call is only defined by the quality of your Wi-Fi connection. This is the part of the connection that we can not control. Quality of the Wi-Fi connection is defined by many parameters, rather than just by the speed of the connection. With a good Wi-Fi connection the quality of the call will be similar to using our regular roaming network.
© 2006-2026 Belmont Telecom Inc., DBA OneSimCard.com. All rights reserved
