All Global System for Mobile Communication (GSM) handsets need a SIM card. It is a small chip that contains the data on your phone number, user ID, rate plan, billing information, and phone service. Its main function is to authorize you to make and receive phone calls. When you hear of a global roaming SIM card, it is simply a SIM card that can be used internationally.

When traveling, it is best to use international SIM cards rather than local SIM cards because it gives the benefit of having only one number. This is very advantageous especially if you are traveling to different countries in one trip. In addition, it offers cheaper rates compared to your local roaming charges.

Of course you are aware that when you travel abroad, your incoming calls are also charged by your local service provider right? Your natural reaction therefore is to limit not just your outgoing calls, but your incoming calls too. Imagine telling your friends and relatives not to call you when you are abroad because you will be charged enormously. How embarrassing!

This kind of situation will never happen to you if you use international SIM cards because incoming calls are free! If not, it will definitely have a very low charge. This means that you can save on money while at the same time keeping in touch with your loved ones.

It is best to use a global roaming SIM card that is prepaid, so that you can activate your GSM mobile without entering into a contract with the service provider. When you purchase the card, there is already an airtime credit in it, and you may recharge the card anytime to lengthen the credit. This SIM card is usually valid for six months but it can be extended as long as you need it.