Compatible Handsets

• Any GSM-style phone will accept your SIM card as long as it has been unlocked for use with your carrier's network. This can come in handy in a number of different scenarios. If your primary phone stops working, you can switch your SIM card to a different device until your primary one has been repaired. Some carriers offer loaner phones in their retail stores to use in this situation. If you plan to travel overseas, you can unlock your device for international use (with your carrier's help) and place a foreign SIM card inside when you arrive. This allows you to use local cell service without having to buy a new phone.
  
  

Address Book

• With removable SIM cards, your address book follows you from phone to phone. In situations where your phone has suffered a major malfunction, you will not lose your carefully maintained contact list, as long as the SIM card is not the source of the problem. SIM cards provide 128 KB of memory to use for storing contacts and other types of data. As long as your address book fits within this constraint, it can be easily transferred. When switching your SIM card to an alternate device, the phone book will automatically become available on the new phone.
  
  

Text Messages

• Your cache of stored text messages will also follow your SIM card. So if you buy a new phone or need to use an alternate for some reason, you will not lose access to important messages that you've saved. GSM-style phones automatically store messages on the SIM card until their 128 KB of available memory is used up, both by text messages and your phone book.
  
  

Phone Theft

• Should your phone ever be stolen, you can obtain a replacement SIM card and link it to your wireless services. This means that you can use an old phone or a loaner from a retail store or friend until you purchase a replacement. While your phone book and text messages will still be lost, you will at least be able to use your services without necessarily having to purchase a new phone right away.