1, the legal mobile phone customized by telecom and mobile phone manufacturers, users must sign a contract with the designated operator to use the mobile phone, and pay the rental fee in full (mostly in the name of deposit).

2. You can't change your card when you make an appointment. After changing the card, the mobile phone will be locked and the phone bill will not be refunded. Despite these limitations, contract machines still have many advantages over bare machines. The supply of bare metal in the market is not guaranteed, the contract machine must have a license, and there is no or little phone bill for a long time after signing the contract.