We are here to help you get answers to your questions about OneSimCard phones and services.
How do I set up SMS text messaging on my phone?
SMS messaging usually works without any additional setup of the phone.
In rare cases when there are issues sending or receiving text messages, please look at the following:
Problem with Sending SMS:
SMSC number should be set as follows:
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1. For Standard  and Plus OneSimCard SIM: +3725099000 for all countries except:
a. China:  +85290296747
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2. For the Expedition (former Data & Roam) SIM as well as for Europe & More SIM: +37256100041
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Special instructions for Apple Phones:
With Apple iPhones to check SMSC:
From the phone dialer Dial *#5005*7672#Â
You will see the SMSC set currently on the phone.Â
To change the SMSC on Iphone dial:Â
Plus and Standard SIMs: **5005*7672*+3725099000# for all countries except China and **5005*7672*+85290296747# if in China.
Expedition (formerly Data & Roam) and Europe & More SIMs in any country:Â **5005*7672*+37256100041#
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If your phone requires the name of Message Center Name enter: SMSC
SMS lifetime is short - must be at least 2 hours or set to Maximum settings.
Try sending SMS from OneSimCard menu
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 Problem with Receiving SMS:
How can I dial '+' on my phone when making call?
Note: You can always dial 00 instead of + when making outgoing calls. For example, to reach OneSimCard customer service in the USA you can just dial 001 617 3138888.
You should consult the phone manual for this info. Different manufacturers have specific ways to access the '+' key, so make sure you know yours.
Here are few known ways:
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Do I need to activate the SIM card when my order is received or purchased from a retail store?
Yes, you will need to activate the SIM card once the order is received.
All OneSimCard international SIM cards and international cell phones with SIM cards are shipped inactive to prevent theft and improve security. Only the person who placed the order for OneSimCard service can activate it.
Activation is very simple: When you receive the SIM, just log in to your account at www.OneSimCard.com and click the large Activate button you will see in the middle of the screen.
Retail Customers: If you purchased your SIM card through an online or brick-and-mortar retail store, you should have received activation instructions inside the product packaging. To activate retail SIM cards, go to www.OneSimCard.com/Retail enter your new OneSimCard international mobile number and fill out the form to register and activate the SIM card. You will be provided specific instructions on the registration page.
Is there a mobile app that will let me recharge my account and other services?
Yes! Our myOneSim app for the iPhone devices will let you easily access many account services, such as recharging your account, checking voicemail, ordering discount voice and text plans, and much more. MyOneSim is available for download from the App store. Find more information in the Help section of your online account.
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DataMax SIM cards can't be managed by myOneSim app at this time
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.
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.
How do I enable roaming on my Android Phone?
This is very simple!ÂThe 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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How much does it cost someone in the US or Canada to call to my OneSimCard cell phone?
For Universal, Expedition, and eSIM World SIM cards, many U.S. and Canadian carriers can charge more than $3/minute to connect to an Estonian mobile number, the primary mobile number for a OneSimCard global SIM card. Your SIM card includes a U.S. number which will be much less expensive for people to call.
Callers can also use one of the Common Access Numbers (CAN) that we provide to you free of charge in more than 10 countries. Your OneSimCard account will simply be charged an additional 20c/min to the incoming rate in the country you are in to receive those calls. There is also the option of ordering a dedicated Personal Extra Number (PEN) in Canada and many other countries that will forward all calls directly to your OneSimCard cell phone. You can see the list of countries where PENs are available here:
You can order a Personal Extra Number when placing your order or later at any time by logging in to your account. Visit our Rates & Coverage page and choose any country to view all rates.
If you would prefer for the caller to pay for calls made, we recommend they buy Peanuts Prepaid. Using this service would guarantee a connection to your OneSimCard mobile phone from the U.S and Canada for 20c/min and it is very easy to use without switching your LD carrier.
For Physical 3-in-1Â DataMax and DataMax eSIM, if you chose to use SIM VOIP app, your friends and family will call the PEN number you are assigned, so in most cases, there will be no tariff for them to call you, and the cost to receive the call is only $0.01/Minute.
I can't send SMS from my iPhone
There is a known bug with iPhone phone book. If you are trying to text to a contact that is entered in the phone book, and the contact is not entered in proper international number format, the SMS will not go through even if you just enter the number in the SMS menu directly and properly.© 2006-2026 Belmont Telecom Inc., DBA OneSimCard.com. All rights reserved