During the agreement period of Unicom contract machine, it is not allowed to separate calling cards. If the phone card is no longer given away, the phone card will be in arrears and will be blacklisted by Unicom. It is recommended that you use this card normally during the agreement period. It is quite cost-effective for China Unicom's 3G package to have no roaming in the whole country. After the agreement expires, you can freely change the package or cancel the contract, so as not to affect your reputation.