Yes. There are a few options available if your phone is locked to the carrier that sold you the phone.

• Try contacting the carrier to see if they unlock it for you.

• You can purchase a travel phone bundle with the SIM at

           http://www.onesimcard.com/international-cell-phones/

To make a call:

• Dial 00-CountryCode-AreaCode-Number and press the TALK/SEND button.
  Example: To call OneSimCard Support in the USA you would dial 00 1 617 3138888 and press TALK/SEND. 

With Europe & More, Univesal and eSIM World that do not use the callback to make a call, you will just get connected.
 
With OneSimCard Plus SIM or Expedition (formerly Data & Roam) SIMs:

After pressing the TALK/SEND button you will see a variable message on the screen (for example 'Wait for call') which you can ignore and your phone will ring back in a few seconds. Answer this ring as you normally would answer any incoming call. Your call will then be connected.

If you are unsure about how to properly dial an international number, follow this link for detailed country by country dialing instructions.

For DataMax, and DataMax eSIM cards, you can place calls using our low cost OneSIM VoIP service. OneSim VoIP costs much less than traditional voice roaming.

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.

Armenia, Austria, Belgium, Bulgaria, Canada, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Gibraltar, Greece, Hungary, Iceland, Ireland, Italy, Kazakhstan, Latvia, Lithuania, Luxembourg, Malta, Monaco, Netherlands, Norway, Poland, Portugal, Romania, Russia, San Marino, Slovakia, Slovenia, Spain, Sweden, Switzerland, Ukraine, United Kingdom, USA and Vatican City

Of course you can! Simply send and receive SMS texts according to your phone's user manual or from the OneSimCard Menu. Receiving SMS is always free. Sending an SMS (text message) is $0.15 - $1.50 depending on the country.

SMS messages sent to a OneSimCard phone should always be sent to the main OneSimCard mobile number rather than to an optional Extra Number, with the exception of new SMS enabled numbers in USA, Canada and UK Mobile available since Jun 3rd, 2014. When replying from OneSimCard phone to the SMS received on USA or Canada SMS capable PEN using Europe & More sim or the Expedition SIM, the main number of the SIM that starts with 372 will be displayed on the text receiver phone. With the Universal SIM, you can select what caller ID will be shown on the SMS receiving party phone.

You can also send SMS messages from OneSim VOIP app at much lower rates.

You can also send a free SMS message to any OneSimCard customer from our web site or by sending email to [email protected], where 372XXXXXXXX is the OneSimCard primary mobile phone number. The maximum number of daily SMS sent to the SIM over email or web is 25.

Please bear in mind that message should be sent in English characters. In addition, it should not be longer than 160 characters including spaces.

These 2 options of sending SMS by email provide completely free way of communicating, as it is usually free for you to send the email and costs nothing for the OneSimCard customer to receive a text message.

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.

• If you have the OneSimCard Menu on your phone (it may be called Sim Application Menu on iPhones or SIM Toolkit on Androids), go to the menu, scroll down to Settings and enter Service Code 2003 and confirm, then Code 000 and confirm. For older SIM cards after this enter Service Code 1101 and confirm. Turn the phone off and then back on. 
  
  
• If you do not have access to the OneSimCard Menu then turn off your phone, remove the battery for 20 seconds, reinstall the battery and then turn back on your 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.