Is there a contract period for the mobile phone building block package?

China Mobile's building block package has a contract period. Building block packaging is a flexible packaging combination. Users can choose appropriate traffic packets, voice packets and short message packets to combine freely according to their own needs. This kind of package often comes with a certain contract period, that is, users cannot change or cancel the package at will during the contract period. The contract period exists mainly to protect the interests of operators, because users will get certain benefits during the contract period, such as giving away traffic, reducing tariffs or providing their services. Users can change or cancel the package at any time, and the operator will lose. The main services of China Mobile include mobile voice call service, short message service, data traffic service, broadband service and its value-added service. In addition, China Mobile also provides various communication-based services, such as mobile payment, cloud storage and Internet of Things.