However, there is one problem that needs attention. In fact, no matter how many stock index accounts you have opened in many futures companies, there is only one exchange code. I can find out that you have opened a futures account, because an ID number can only be opened once in the exchange. If you open an account with another futures company, the company will apply for the transaction code of your last account opening. The transaction code consists of two parts, company code and customer code. Among different company account opening transaction codes, only the company code has changed, but the customer code has not changed.