1 Bank of Communications APP, enter the column of "Treasury bonds, securities and futures", and click "Open an account in custody account" in the savings bonds (electronic) drop-down item to open it.

2. The mobile phone can be set to receive the dynamic password when it is turned on.

. National debt (national debt; Governmentloan, also known as national bond, is a creditor-debtor relationship formed by the state on the basis of its credit and in accordance with the general principles of debt. National debt is issued by the state, which is a kind of government bond issued by the central government to raise financial funds. It is a debt certificate issued by the central government to investors, promising to pay interest and repay the principal at maturity within a certain period of time. Because the issuer of national debt is the country, it has the highest credit and is recognized as the safest investment tool. According to the different ways of borrowing debts, national debt can be divided into national bonds and national loans. According to the different repayment periods, national debt can be divided into fixed-term national debt and irregular national debt.