American mobiles phones operate differently to mobiles elsewhere in the world. These are some of the key differences:

Mobile networks in the USA have been slow to adopt the GSM standard and although there is a good choice of competing mobile phone networks in the States, only two ( AT&T and T-Mobile ) operate nationwide GSM networks. Furthermore, the GSM networks in the States use the 850 Mhz and 1900 Mhz frequencies as opposed to the 900 Mhz and 1800 Mhz frequencies used elsewhere in the world. To use a US SIM card you will need to have a tri-band phone that works on the 1900 Mhz frequency or preferably a quad-band phone that works on the 850 Mhz and 1900 Mhz frequencies. Many newer mobile phones will work in the United States but it is best to double-check with your phone manufacturer.

Americans pay for both incoming and outgoing calls. That's right, all American mobile networks charge you to receive as well as make calls. The rate for incoming calls is the same as the national call rate. However the price per minute on a monthly plan is relatively low so you generally still pay less with a phone in the States compared with most other countries.

The cost of calling an American mobile phone is exactly the same as calling an American landline. This makes it very cheap if you divert your home phone to your US phone and friends can call your mobile in the US without worrying about call costs. In most costs it will be cheaper for your friends and family to call your US mobile phone than to call the mobile you normally use at home.

American mobile phones have the same area codes as regular landlines. This means that your phone number is indistinguishable from a regular American phone number.