For Universal, Expedition, & eSIM World ONLY: Just dial 099 "Send" from your OneSimCard phone and in few minutes the balance will be displayed on the screen of your phone. Customers with iPhones can use OneSimCard Assist app to check balances and many other things.

You can always check your current balance by logging onto your OneSimCard account at www.onesimcard.com.

Yes! Just select "nano size" or buy a 3-in-1 SIM that contains all 3 sim sizes during checkout.

OneSimCard can help you save a lot of money on international roaming abroad over large domestic carriers. Check out these rate tables to compare international roaming offerings from AT&T, Verizon,  and T-Mobile. 

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.

Through a unique partnership with Viber, your primary OneSimCard number (+372) can be called free of charge for any Viber user! (requires activation and special dialing instructions, see below)

HOW: When this feature is activated, Viber users can call OneSimCard numbers for free by using a special dialing format +372800XXXXXXXX, where XXXXXXXX is the rest of the OneSimCard phone number after 372. For example, a OneSimCard user with the phone number +37212345678 should be called by dialing +37280012345678.

TO ACTIVATE: Log in to your OneSimCard account and go to the My SIM Cards menu. Scroll down to where it says "Incoming Viber Calls" and click Enable to activate this option.

COST: The call is free for the Viber user. The cost of receiving the Viber call is the same as receiving a call through a Personal Extra Number (PEN), i.e. the regular incoming call rate in the country you are in plus 20c/min. In countries with free incoming calls, like Italy or Japan, the cost will be just 20c/min.

PLEASE NOTE:

• When dialing in Viber, if Viber user chooses the Estonian country code in the menu then they should just dial 800XXXXXXXX because the +372 is added automatically.
• If the “free calls to OneSimCard from Viber” option is not activated for a particular OneSimCard number, when a Viber user dials +372800XXXXXXXX they will hear an automatic message: “The mobile phone is either switched off or out of coverage area.”

PLEASE NOTE: Viber is not available for the DataMax or DataMax eSIM

In order to add airtime instantly, simply register a credit card with us on our website.

There are several ways to add airtime to your OneSimCard service.
Automatic Recharge - recommended:

1. Just log on to your account at www.onesimcard.com and set auto-recharge in the Recharge Menu. Funds will be added to your account when your balance drops below the threshold you set.

From the phone using your credit card (Universal, Expedition and eSIM World only):

1. a) From the phone dial pad dial 098YYYY*XX. Talk. YYYY = Last 4 digits of the credit card used last at OneSimCard.com. YY = Amount from 25 to 99 USD

 For example, if you need to add $50 and the last 4 digits of the credit card registered with us is  8654:
You would dial 0988654*50 and press TALK. In few seconds you will get a confirmation message with  your new balance.
* is a star character located on the keypad
From the phone using 1SIM Fund:
 a) From the phone dialpad dial 098YYYY*XX. Talk. YYYY -  4 digits PIN you created in 1SIM FUND menu. YY Amount from 25 to 99 USD

 For example, if you need to add $50 and the 1SIM FUND PIN is  8654:
You would dial 0988654*50 and press TALK. In few seconds you will get a confirmation message with  your new balance.
* is a star character located on the keypad

From the OneSimCard.com web interface:

1. You must log in at www.onesimcard.com each time you wish to add funds.
2. The minimum recharge amount is US $25.00
3. Using Recharge PIN purchased from a dealer:

If you purchased a recharge PIN from OneSimCard Authorized dealer, you can recharge your account from OneSimCard handset from OneSimCard - Add Credit menu. When the Add Credit menu is selected, enter the 10-digit PIN and press the Talk (Send) button. 

Unless otherwise noted, all phones sold on OneSimCard.com come with our standard 90-day replacement warranty. This warranty covers any mechanical defects, but does not include damage due to Acts of God, neglect, water damage, or other intentional or unintentional abuses of the phone. OneSimCard does offer extended warranties available for purchase.

Yes. If you would like to upgrade your Standard, Plus, Europe & More, Expedition version SIM card to a Universal, DataMax, or DataMax eSIM SIM card, or upgrade a regular size SIM card to a micro-SIM card (for example, to use in an iPhones) then place your order online by selecting the product option on our Mobile Accessories page here. In the shopping cart you will be able to select your upgrade.