Is it illegal for idle fish to let others add their mobile phone numbers?

It is not illegal for idle fish to let others add their mobile phone numbers. According to relevant information, idle fish is a c2c marketing method, so there is no strict requirement for the contact information of sellers and buyers. When you discuss the contact information, a pop-up window will pop up in the chat window of the platform. In order to protect the rights and interests of buyers and sellers, it is safer to trade on the platform as much as possible.