Unicom will let you sign a contract and let you agree to the contract when doing business.

Call signature service is a kind of value-added service that transmits the preset signature information to the other party when the user calls. Both calling and called users can customize. Before the call starts (one party's mobile phone rings) or after the call ends, the system automatically pushes the call signature information (publicity information, product information, promotion information, customer care, etc.). ) preset by the user to the other party's mobile phone, so as to achieve the purpose of corporate image promotion and commercial information transmission.