My dad is in America now, and I want him to bring an Iphone4s back. What is the concept of lock machine without contract? What do you mean you want to decode it?

First of all, there are two kinds of mobile phones in America. One is a contract machine and the other is an unlock machine.

Let's talk about the contract machine first. The contract machine first binds these fixed operators, such as AT & amp； T and sprint and so on. The pre-tax price is $ 199. If you want to buy their contract machine, you must sign a two-year contract. If it takes less than two years, it is a breach of contract. This will affect your credit. Except, of course, some things you don't say. To sign a contract with these companies, you must first have an American social security code. If not, you must pay a deposit in 500 yuan. Return it after one year. Also, the contract machine cannot be unlocked (at least for half a year).

Then there is the lock opener. The price of the unlocking machine is 650 dollars. But it only applies to GSM networks. In other words, some CDMA cards of China Telecom and China Unicom cannot be used, but they can be moved. So if you want to buy, you have to consider one of these two factors. Generally speaking, the unlocking machine is more suitable. But you need to make an appointment half a month in advance. This needs to be remembered.

That's basically it. You can keep asking questions.

If you have time, you can log on to Taobao and search for the shop "Travel Dresser", which contains many nice clothes. It is more suitable for traveling abroad or studying abroad. Thanks for reading.