We are here to help you get answers to your questions about OneSimCard phones and services.
I can make calls through OneSim VoIP. However incoming calls are going through my roaming SIM. What's wrong?
If your incoming calls are not being routed through the OneSim VoIP app then you are either not connected to Wi-Fi or the OneSim VoIP app is not active.Is text messaging available on the OneSim VoIP App?
OneSimCard SIM VoIP users with US and Canadian numbers may now send and receive text messages over the OneSim VoIP app on iPhone and Android. The cost to sending a message is $0.05 per text to most countries. Receiving message is $0.05. Â
Â
OneSimCard SIM VoIP users with US and Canadian numbers may now send and receive text messages over the OneSim VoIP app on iPhone. The cost to send or receive each message is $0.05.Â
How does OneSim VoIP work when the call is received?
When someone dials your OneSim VoIP enabled Personal Extra Number (PEN), the system will first check if your OneSimCard phone is registered with the OneSim VoIP app on a Wi-Fi network. If it is registered, the call will be sent using VoIP. If the OneSim VoIP app is not running or it is not registered on a Wi-Fi network, then the call will be sent using the standard OneSimCard roaming network and charged our standard roaming rates.Can I use Facetime, WhatsApp, Telegram, Discord, iMessage, and other messaging Apps with eSIM?
For DataMax eSIM, you can use these Apps as you already do. Please ensure your messaging account is already setup with your primary carrier’s phone number because you cannot sign up for these services with the DataMax eSIM number.
Additionally, the eSIM data service can be used for the actual data part of your communications. So, when you are installing eSIM on phone, you can select the Primary service for Facetime and iMessage and then if your selected eSIM to be your primary data service, the communications will go over eSIM mobile data.
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:
Â
There are no special instructions to receive calls in these countries.
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 Data Roaming turned on for eSIM to work?
Yes. Data Roaming should be enabled on your phone for eSIM for data to work. Calls and texts on eSIM World should work with or without it.
How does eSIM works?
How do I install my eSIM?
Before purchasing, please ensure you have verified that your device is unlocked and one of the supported devices. Installation is completed by using your phone to scan the QR code of the purchased eSIM. You may scan the QR code by displaying it on the computer screen, another device, or a printed copy.
If you’ve already purchased OneSimCard eSIM, you can see full installation instructions and access your QR code from the Recharge menu in your online account. Make sure eSIM is selected in the Select SIM Card drop down menu.
If you have not purchased your eSIM yet, learn more about international eSIM here.
When making an outgoing call how do I select which way the call should go: through regular roaming or through OneSim VoIP?
To make an outgoing call using OneSim VoIP, you need to be registered on a Wi-Fi network and have the OneSim VoIP app running on your phone. You should make the call using the OneSim VoIP app dial pad. To make a call the regular roaming way,you should make a call from your regular phone dial pad.Â
NOTE: Regular roaming calling is NOT available on DataMax or DataMax eSIM cards. To use voice you will need to use the OneSim VoIP app
© 2006-2024 Belmont Telecom Inc., DBA OneSimCard.com. All rights reserved