Is it illegal for brokers to open an account in an intermediary?

It is not illegal, as long as the account opening itself is legal and there is no fraud.

The law doesn't stipulate, at most it violates the company's regulations. Now the number of accounts opened by securities companies is not illegal. The account you open now may be used by this customer in the future. It's not illegal at all, nor is it a customer. Is to open an account first

If a securities company wants to find someone to open an account for them, it must require that person to have a securities qualification certificate. Otherwise, it's illegal. If the violation is investigated by the CSRC, it will be fined10 million yuan. Therefore, securities companies will not take this risk. Generally, the securities broker or team leader tells you privately that he will not sign the contract.