We are here to help you get answers to your questions about OneSimCard phones and services.
Are there any additional roaming charges?
There are NO additional roaming charges. The rates you see listed on our Rates & Coverage page are the only rates you will be charged when making or receiving calls on your OneSimCard enabled cell phone. This is true for using regular cellular voice or 1SIM VoIP App.What are the advantages of using OneSim VoIP?
The main advantages are significant cost savings and the ability to call from countries where there is no voice roaming coverage available, or for DataMax or DataMax eSIMs
OneSim VoiP can be used from any Android or Apple ( iOS) device to make international LD calls even when you are not traveling. OneSim VoIP does not require having OneSimCard SIM being installed in the phone. OneSim VoIP can be used with Wi-Fi or 3G/4G - no difference. You just need to have OneSimCard account with the SIM VoIP capable PEN. Calling using OneSim VoIP will cost most of the time less than any other way of calling.
OneSim VoIP is available with the following SIM cards: Plus, Expedition (formerly Data & Roam),  Europe & More, DataMax, and DataMax eSIM.I have a OneSimCard SIM and my phone will not register on a roaming network, what's wrong?
Sometimes when moving from the USA, Canada or Mexico to another country, the SIM card will need to be reset to properly register on a new country roaming network.
What should I do if my OneSimCard phone or SIM card is lost or stolen?
If your phone or SIM card is lost or stolen and automatic recharge is on, this could be a serious problem.
To prevent this, log in to your account and activate the option to block your service immediately after you notice your phone or SIM card is missing. You can find this option in the My SIM Cards menu. Your OneSimCard service for this SIM card number will be instantly blocked. The remaining balance on your lost SIM can be transferred to another SIM card on your account or you can order a replacement SIM card if you would like to keep your phone numbers from the lost SIM. However, the existing data package can’t be transferred to the new SIM card.
Alternatively, you can contact customer service online or call 001-617-313-8888 for assistance.
Does voicemail work with OneSim VoIP?
Yes. If you are not available to answer the OneSim VoIP call or if the OneSim VoIP app is turned off, the call will be routed through our standard roaming network. If the call is not answered it will be sent to your OneSimCard voicemail box.Â
NOTE: Voicemail is not available for DataMax or DataMax eSIM cards with OneSim VoIP.
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.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.
Can I move balances from one SIM card to another?
We allow moving balances from one SIM card to another in the following cases:
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.
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.
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